ML20206M989

Medical Misadministration Rept:Medical Misadministrations Reported for 1985 & 5-Yr Assessment of 1981-85 Repts

ML20206M989
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Issue date:	06/30/1986
From:	Pettijohn S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
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ML20206M920	List: ML20206M914 ML20206M989
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TASK-AE, TASK-N602 AEOD-N602, NUDOCS 8607010339
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a AE00/N602 MEDICAL MISADMINISTRATION REPORT Medical Misadministrations Reported for 1985 and Five-Year Assessment of 1981-1985 Reports s

by the

- Office for Analysis and Evaluation of Operational Data

. Nonreactor Assessment Staff June 1986 i

Prepared by:

Samuel L. Pettijohn This report characterizes the Medical Misadministration database maintained by the Office for Analysis and Evaluation of Operational Data. This report does not contain detailed analyses of individual events, but focuses on an attempt to identify potential and actual problem areas, and address the status of NRC activities in those areas.

8607010339 860625 NEXD PDR ORG

s TABLE OF CONTENTS Pa5Le

1. INTRODUCTION..................................................... I

2. THERAPY AND DIAGNOSTIC MISADMINISTRATIONS REPORTED FOR 1985...... 4 2.1. General .................................................... 4 2.2 The ra py Mi s a dmi n i s tra tion s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Diagnostic Misadministrations............................... 6 2.4 Corrective Actions.......................................... 9 2.5 Findings................................................... 10

3. THERAPY AND DIAGNOSTIC MISADMINISTRATIONS REPORTED FOR 1981 THROUGH 19 8 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1 Genera 1.................................................... 10 3.2 The ra py Mi sa dmi ni s tra ti on s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2.1 Ge n e ra 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2.2 AE0D Case Study Report on Therapy Misadministrations.................................. 14

~3.2.3 Therapy Misadministrations Reported to NRC Since August 1984................................... 15 3.3 Diagnostic Misadministrations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3.1 G e n e ra l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3.2 Percent of NRC Licensees Reporting M i s a dmi n i s tra ti o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3.3 Licensees Reporting Multiple Misadministrations..... 18 3.3.4 Misadministrations Involving the Administration of a Dose Differing from the Prescribed Dose by G rea te r tha n 50% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.3.5 Causes and Corrective Actions for Misadministrations. 21 l

l 3.4 Findings................................................... 22 APPENDIX A -

SUMMARY

DESCRIPTION OF THERAPY MISADMINISTRATIONS REP 0RTED......................................... 23 APPENDIX B -

DIAGNOSTIC MISADMINISTRATIONS REPORTED TO NRC, 1981-1985........................................ 33 l

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1. INTRODUCTION The Nuclear Regulatory Commission (NRC) regulates certain aspects of the uses of reactor produced radioisotopes

• in nuclear medicine and therapeutic radiology. Nuclear medicine is defined as that specialty in the practice of medicine dealing with the diagnostic, therapeutic (exclusive of sealed sources), and investigative use of radionuclides. Therapeutic radiology is that branch of radiology which deals with the therapeutic application of ioniz?ng radiation, including gamma rays, as well as particulate radiation from any artificially and naturally radioactive materials, as well as X-ray generators and particle accelerators.

As a result of a number of serious misadministrations involving radiation therapy in the 1970s, and to assure the complete and consistent reporting of

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such events, in 1980 the NRC promulgated regulations (10 CFR 35.41 through 35.45) to require the reporting of diagnostic and therapy misadministrations involving nuclear medicine studies or radiation therapy, although the regulations did not define the occurrence of a misadministration to be a violation of any NRC regulation.

Diagnostic misadministration, as used in NRC regulations, refers to the misadministration of radioisotopes during diagnostic procedures (e.g., brain scans and bone scans). Therapy misadministration, as used in the regulations, refers to the misadministration of radiation during therapeutic procedures.

The regulations, which became effective on November 10, 1980, define a mis-administration to mean the administration of:

(a) a radiopharmaceutical or radiation from a sealed source other than the one intended; (b) a radiopharmaceutical or radiation to the wrong patient; (c) a radiopharmaceutical or radiation by a route of adminis-tration other than that intended by the prescribing physician;

• The Atomic Energy Act of 1954, as amended in 1974, limits the NRC's regulation of radioactive materials to reactor produced isotopes.

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% (d) a diagnostic dose of a radiopharmaceutical differing from the prescribed dose by more than 50%;

(e) a therapeutic dose of a radiopharmaceutical differing from the prescribed dose by more than 10%; or (f) a therapeutic radiation dose from a sealed source such that .- w errors in the source calibration, time of exposure, and treatment geometry result in a calculated total treatment dose differing from the final prescribed total treatment dose by more than 10%.

Items (a), (b), (c), (e), and (f) apply to therapy misadministrations, and (a), (b), (c), and (d) apply to diagnostic misadministrations. The NRC requirement to report these misadministrations was not made an item of

" compatibility" for Agreement States (i.e., the States are not required to establish regulations requiring their licensees to report misadministrations);

however, six Agreement ~ States have adopted similar reporting requirements.

Any regulation of radiation therapies that use linear accelerators or X-ray

- equipment is done by the individual States. As a result, misadministrations involving these types of radiation therapy are not required to be reported to the NRC. Any reporting requirement for these types of therapy would be those imposed by the individual States.

The Commission's purpose in requiring the submittal of misadministration reports to the NRC is to verify that their causes are properly identified and that licensees implement appropriate corrective actions to prevent recurrence.

However, according to the Office of Inspection and Enforcement (IE) (Comment received from " peer review" of the AE0D Preliminary Case Study Report, Therapy Misadministrations Reported to the NRC Pursuant to 10 CFR 35.42, June 1985),

"In most cases, there has been no regulatory basis that would support NRC action to either require corrective actions or to enforce those that the licensee has voluntarily proposed."

Written reports of misadministrations are submitted by licensees to the appropriate NRC Regional Office. The Regional Office reviews a licensee's misadministration report and either performs a special inspection to investi-

. gate the misadministration, or includes a review of the misadministration in the next scheduled inspection of the licensee. In the case of therapy misadministrations, the Regional Office will normally make a determination as

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to whether a medical consultant should assess the effects of the misadminis-tration on the patient. The NRC's Office of Inspection and Enforcement (IE) and Office of Nuclear Material Safety and Safeguards (NMSS) receive copies of licensee misadministration reports. The Office for Analysis and Evaluation of Operational Data (AE0D) also receives copies of the reports, reviews them for generic problems, prepares abstracts, and enters pertinent data into a computerized database.

There are approximately 400 NRC licenses that authorize licensees to perform teletherapy treatments, 600 that authorize licensees to perform brachytherapy treatments, and about 600 that authorize licensees to perform radiopharma-ceutical therapy treatments. About 2700 NRC licenses authorize 2400 licensees to perform diagnostic studies (nuclear medicine studies) and radiation therapy.

These licensees rep 6Fted 34 therapy misadministrations and about 2000 diagnostic misadministrations for the 1981-1985 period.

The significance in the occurrence of any event stems from the potential impact of the event on public health and safety. One dimension of event risk is the frequency of the event; a second is the magnitude of the potential impact of the event. AE0D has used the data collected on misadministrations for five years to estimate error rates for certain misadministration events.

Teletherapy Misadministration - There were 21 therapy misadministration reports that involved teletherapy machines.*

In these 21 events, a total of 72 patients were overtreated or undertreated. Using data from the 1983 Patterns of Care Study of the American College of Radiology, the error rate per patient is estimated to be about 0.015%.

Diagnostic Misadministration -

There were about 2000 diagnostic misadministrations reported to NRC over the five-year period.

A recent study by the Technologist Section of the Society of Nuclear Medicine estimated that about 10 million diagnostic procedures are performed annually in the United States. Since NRC regulates only 23 of the 50 states, it is estimated that about 4 million procedures are performed annually by NRC licensees. Thus, the diagnostic error rate per procedure is estimated to be about 0.01%.

• A device that uses a radioactive cobalt-60 or cesium-137 source to produce a radiation beam used in the treatment of patients for cancer.

s s Therapy misadministra'tions are associated with procedures in which large doses of radiation are administered to patients to achieve a therapeutic effect.

Diagnostic misadministrations are associated with procedures designed to permit a diagnosis to be made with little exposure to the patient. Therapy misadministrations have larger potential impacts on the health of the patient than diagnostic misadministrations. Since both teletherapy misadministrations and diagnostic misadministrations have about the same estimated error rate, the therapy misadministrations as a class appear to be individually and collectively more significant than diagnostic misadministrations. For this reason, therapy misadministration reports are reviewed in detail, while diagnostic misadministration reports are reviewed primarily from a collective or statistical viewpoint.

This report contains a compilation of data for misadministrations reported to the NRC for 1985, and an overview of misadministrations reported to the NRC for the period 1981 through 1985. Section 2 contains a compilation of data

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for 1985, including a discussion of therapy misadministrations and diagnostic misadministrations. Section 3 contains an analysis of the therapy and i

diagnostic misadministrations reported to the NRC for 1981 through 1985, and

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$ection 4 contains the report findings. Appendix A contains a summary description of the therapy misadministrations reported to NRC. Appendix B contains the yearly distribution by cause code and corrective action code for diagnostic misadministrations involving the wrong radiopharmaceutical.

2. THERAPY AND DIAGNOSTIC MISADMINISTRATIONS REPORTED FOR 1985 2.1 General l

l Table 1 summarizes the statistics for the medical misadninistrations reported l to the NRC for 1985. For this period, 297 of the approximately 2400 NRC licensees authorized to perform nuclear medicine studies or radiation therapy reported one or more misadministrations, a total of 384 reports involving 414 patients. Of the 384 reports of misadministrations for 1985, 380 (99%)

reported diagnostic misadministrations, and four (1%) reported therapy misadministrations.

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5-TABLE 1 ,

I Statistics for Medical Misadministrations Reported for 1985 Diagnostic Therapy Total Number of Reports 380 4 384 Number of Patients Involved 410 4 414 Number of Licensees Reporting 293 4 297 2.2 Therapy Misadministrations

- Four therapy misadministrations were reported in 1985. One of the misadminis-trations involved teletherapy (treatment at a distance), one involved brachy-therap (treatment from implanted sources), one involved a strontium-90 eye

_ applicator, and one involved radiopharmaceutical therapy (iodine-131 for hyperthyroid treatment). Table 2 presents data on the type and probable cause of the misadministrations.

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The teletherapy misadministration was caused by errors in dose calculations involving treatment time. The brachytherapy misadministration was caused by a failure to promptly employ a computer program to verify the accuracy of the treatment plans. The therapy misadministration involving a strontium-90 '

eye applicator resulted from a unique error--the attending physician misinterpreted an area containing scar tissue in the medial limbal area of the right eye as the area to be treated--while the misadministration involving the iodine-131 was caused by the dose calibrator function or range switch being set to the wrong position due to simple human error.

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AE00 issued a case study report (AE0D/C505) in December 1985 that analyzed i

16 teletharapy misadministrations and two brachytherapy misadministrations that were reported to NRC between January 1981 and July 1984. The general

! conclusion drawn from the analysis was that the occurrence of therapy mis-administrations can be reduced by improvements in licensee quality assurance l procedures, especially as they relate to verifying the accuracy of patient dose r F

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• calculations. The teletherapy and brachytherapy misadministrations that occurred in 1985 might have been prevented by quality assurance procedures directed to verifying dose calculations.

TABLE 2 Type and Probable Cause of Therapy Misadministrations Reported for 1985 Dose different from prescribed by >10%

(Teletherapy) 1 Failure to verify treatment time Dose different from prescribed by >10%

(Brachytherapy) 1

, Failure to have program to verify accuracy of treatment plans to assure delivery of correct dose Dose different from prescribed by >10%

. (Sr-90 Eye Applicator) 1 No specific cause known Dose different from prescribed by >10%

(Radiopharmaceutical) 1

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• Dose calibrator range or function switch set to wrong position 2.3 Diagnostic Misadministrations Table 3 presents data for 1985 on the number of diagnostic misadministrations by the type and cause of misadministration. Of the 380 total reports, 294 involved the administration of the wrong radiopharmaceutical to a patient, and 67 involved the administration of a radiopharmaceutical to the wrong patient (92% of the reported misadministrations were of these two types). The remaining diagnostic misadministrations involved four reports involving the wrong route of administration, and 15 reports in which the diagnostic dose of a radiopharmaceutical differed from the prescribed dose by greater than 50%.

AE0D developed the cause categories used in Table 3 after a review of a sample group of typical misadministrations. All of the causes involve human error.

With regard to administration of the wrong radiopharmaceutical, the data show

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~7- l TABLE 3 Type and Cause of Diagnostic Misadministrations Reported to NRC for 1985 i

Wrong Radiopharmaceutical 294 Radiopharmaceutical received from radiopharmacy was mislabeled 16 Physician's order misinterpreted 42 Errors in preparation or delivery of dose:

Mix-up of radiopharmaceutical doses stored in lead pigs 71 Wrong reagent kit used to prepare dose 18 Lead pigs or syringes were mislabeled 20 Mix-up of syringes containing radiopharmaceuticals 31 Other causes:

Nuclear medicine requisition was not checked 11 Insufficient information 61

, - Miscellaneous 24 Wrong Patient 67 Patient answered to wrong name 15 Wrong patient's name on requisition 15 Physician's order misinterpreted 1 Patient's ID was not correlated with type of study 25 Wrong patient delivered to nuclear medicine department 7 Insufficient information 1 Other 3 Wrong Route of Administration 4

! Procedure not understood 1

! Insufficient information 2 Other 1 Diagnostic Dose Differing from Prescribed Dose by 50% 15 Dose calibrator misread 1 Dose calibration range of function switch set to wrong position 2 Insufficient information 1 Other 11 Total Number of Reports 380

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1 that 16 of the 294 events (5%) resulted from receipt of mislabeled doses from a radiopharmacy. For the remainder of the events, 42 (15%) resulted frcm misinterpretation of the physician's order, and errors in the preparation or delivery of doses accounted for 140 (48%). Another 96 reports (32%) had other causes, or contained inadequate information from which to assign a cause.

The dominant causes for the wrong patient events were (a) failure to correlate the patient's identification with the study, 25 events (37%); (b) the patient answering to the wrong name, 15 events (22%); and (c) the wrong patient's name being on the requisition, also 15 events (22%). Relatively simple quality assurance procedures (check the patient identification against the study, ask the patient to state his name) would reduce the frequency of these events.

The remaining two types of diagnostic misadministrations, wrong route of administration and excess dose, had diverse causes.

Although most of the diagnostic misadministrations in 1985 involved technetium-99m, three involved therapy dores of iodine-131 that were mis-

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administered by technologists.* In these cases, the technologists were not familiar with the type of study requested, or did not follow the physician's prescription. On July 22, 1985, the Office of Inspection and Enforcement (IE) issued an Information Notice describing previous similar events involving iodine-131 and the precautions that could prevent the occurrence of these types of events. One of the iodine-131 events occurred in 1985 after the Notice was distributed.

In addition to the diagnostic misadministrations in 1985 that involved therapy doses of iodine-131, one of the 1985 diagnostic administrations involving technetium-99m involved the administration of 200 millicuries of technetium-99m (ten times the prescribed dose) to a patient. This resulted

( from the technologist making an error in reading the dose calibrator.

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! *Several similar misadministration cases have been reported since the l misadministration reporting requirement became effective in November 1980.

Generally, doses of iodine-131 that are 1 millicurie or more are considered l to be in the therapy range for iodine-131. For example, the typical dose range for iodine-131 used in the treatment of hyperthyroidism is 1 to 8

millicuries.

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, 2.4 Corrective Actions Table 4 shows the corrective actions proposed by licensees. Approximately 204 (50%) of these corrective actions involved the retraining of. personnel or implementing new radiopharmaceutical labeling and handling procedures.

TABLE 4 Corrective Actions Proposed by Licensees in

> 1985 Diagnostic Misadministration Reports Type of Corrective Action Number of Reports Implement new procedures requiring technologist to check patient's chart for physician order 30 Implement new radiopharmaceutical labeling and

. handling procedures, e.g., color coding, segregation of radiopharmaceuticals, etc. 62 Implement new procedures for patient identification, i.e., ask patient to state or write name, check

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patient SSAN, use of secondary identification, as well as patient ID bracelet 22 Reinstruct personnel 142 Reprimand technologist or other personnel 23 Improve supervision of personnel 6 Not Specified 31 Other 64 Total 380

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2.5. Findings Findings that can be drawn from this review of misadministrations reported to the NRC for 1985 are as follows:

(1) Four therapy misadministrations occurred in 1985: one tele-therapy treatment, one brachytherapy, one radiopharmaceutical therapy; and, reported for the first time, one therapy using a strontium-90 eye applicator.

(2) Essentially all of the diagnostic misadministrations for 1985 involved either the administration of the wrong radiopharma-ceutical or the administration of a radiopharmaceutical to the wrong patient. The number, type, and cause of diagnostic misadministrations are about the same as reported for 1984.

The causes reported by licensees are generally the same as have been reported in the past; that is, simple errors associated with (1) preparation of radiopharmaceuticals, (2) processing nuclear medicine requisitions, and (3) patient identification.

(3) There were three diagnostic misadministrations involving the administration of millicurie doses of iodine-131. The administered doses were in the dose range that would normally be administered for therapy. Hence, the risk to the patient was comparable to the risk in therapy of iodine-131 misadministrations.

3. THERAPY AND DIAGNOSTIC MISADMINISTRATIONS REPORTED FOR 1981 THROUGH 1985 3.1 General This section contains a discussion of therapy misadministrations and a review of diagnostic misadministrations reported to the NRC by NRC licensees for 1981 through 1985.

, Table 5 shows the number and type of therapy and diagnostic misadministra-tions reported to the NRC for each year from 1981 through 1985. The number of therapy misadministrations reported annually varied from 4 to 12. The most frequent type of therapy misadministration involved teletherapy, ranging from nine in 1984 to one in 1985. There is no apparent reason for the high number of events occurring in 1981 and 1964.

For diagnostic misadministrations, the data in Table 5 show that the number of diagnostic misadministrations reported annually varies from 430 in 1981 to 334 in 1983. The total number of diagnostic misadministrations reported for each of the five years, 1981 through 1985, shows a downward trend. When the data are disaggregate'd into types of diagnostic misadministrations, it can be seen that two types of misadministrations--wrong radiopharmaceutical and wrong patient--comprise over 90% of the total reported misadministrations in any year. In most yeahi, these two types represent 95% to 98% of the reported events.

The annual number of diagnostic misadministrations in which the wrong radio- '

pharmaceutical was used does not vary much over the five year period, ranging from 242 in 1982 to 294 in 1985. There does not appear to be any marked trend in the number of these events reported annually. In contrast to this type of diagnostic misadministration, the number of wrong patient events does vary widely, ranging from 121 in 1981 to 67 in 1985. The annual number of these wrong patient events shows a decrease with time, and appears to be the reason l that the total number of diagnostic misadministration reports shows a downward l trend over the period.

l 3.2 Therapy Misadministrations 3.2.1 General

As shown in Table 5, a total of 34 therapy misadministrations were reported to the NRC for 1981 through 1985 (see Appendix A for summary description).

l Twenty-one of the therapy misadministrations involved teletherapy treatment, six involved brachytherapy treatment, six involved radiopharmaceutical treatment, and one involved treatment with a strontium-90 eye applicator.

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2 TABLE 5 Misadministrations Reported to NRC for 1981-1985 Therapy Misadministrations Year Type of Therapy 1981-Misadministration Reported 1981 1982 1983 1984 1985 1985 Dose different from prescribed by >10% (Teletherapy) 6 2 3 9 1 21 Dose different from prescribed by >10% (Brachytherapy) 2 1 1 1 1 6 Dose different from prescribed by >10% (Sr-90 eye applicator) 0 0 0 0 1 1 Wrong Radiopharmaceutical 1 0 0 0 0 1 Dose different from prescribed by >10% (Radiopharmaceutical) 1 1 0 2 1 5 Total 10 4 4 12 4 34 Diagnostic Misadministrations Year Type of Diagnostic 1981-Misadministration Reported 1981 1982 1983 1984 1985 1985 Wrong Radiopharmaceutical 293 285 242 276 294 1390 -

Wrong Patient 121 117 75 90 67 470 Wrong Route of Administration 2 4 1 1 4 12

Dose Different from Prescribed by >50% 14 11 16 30 15 86 Total 430 417 334 397 380 1958 Number of Licensees Reporting 351 355 293 318 293 817*

Number of Patients 517 451 437 442 410 2257

• Some licensees reported in more than one year.

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s In the 21 teletherapy misadministration events, 73 patients were over- or under-treated, with most events involving the overtreatment of patients. Using data from the Patterns of Care Study of the American College of Radiology, the error rate per patient for teletherapy misadministrations has been calculated to be 0.015L

• Data from which error rates could be calculated were not available for brachytherapy and radiopharmaceutical therapy.

One teletherapy misadministration involved the undertreatment of 53 patients over a three year period, and one brachytherapy misadministration and two radiopharmaceutical therapy misadministrations also involved the under-treatment of patients. Twenty-six of the 34 therapy misadministrations were included in the AEOD case study on therapy misadministrations, issued in December 1985, that is discussed below. Eight of the misadministrations

- occurred after the period addressed by the case study.

Eight 6f the therapy misadministrations also were determined by the Commission to be abnormal occurrences. The routine evaluation of misadministrations for potential A0 reporting began in 1984. Thus, the eight therapy A0s all occurred i in 1984 o'r later. It can be seen from Table 5 that 16 therapy misadminis-

, _ trations occurred in 1984 and 1985. About half of these have had consequences, or potential consequences, that led to their designation as A0s, which points to the significance of these events.

4 i *This error rate is calculated from data contained in the results of the American College of Radiology's (ACR) Patterns of Care study. The survey showed that there were 820 cobalt-60 teletherapy machines in use in the

, United States in 1980, and that about 227 new patients are treated per year per machine. This gives about 186,140 new patients treated per year.

Since NRC regulates only about half of the therapy facilities in the United States (23 States are regulated by NRC), about 93,070 patients 2 per year, or about 465,350 patients for the five year period from January 1981 through December 1985, were treated in NRC-licensed facilities.

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3.2.2 AE00 Case Study Report on Therapy Misadministrations The AEOD case study (AE0D/C505) on Therapy Misadministrations Reported to the NRC Pursuant to 10 CFR 35.42 was published in December 1985. The study included an analysis of the 16 teletherapy and two of the brachytherapy misadministrations that occurred between 1981 and July 1984. The major findings were:

(1) Most of the 16 teletherapy misadministrations and the two brachytherapy misadministrations could have been prevented by independent verification of patient dose calculaticns.

(2) A teletherapy misadministration that involved 53 patients over three years involved human error in measuring the.

transmission of ccbalt-60 radiation through a wedge filter.

NRC regulations issued in November 1980 that require tele-i therapy machine calibration (10 CFR 35.21) do not require that correction factors for beam mcdifiers such as wedge filters be verified during the annual calibration of the teletherapy machine.

l The case study recommendations related to these findings were:

(1) The NRC's Office of Nuclear Material Safety and Safeguards

,- (NMSS) should communicate the information contained in the i report to the affected licensees.

(2) NMSS also should consider the following actions with regard l to establishing quality assurance requirements for radiotherapy l facilities licensed by NRC, Contact appropriate professional organizations to encourage and support the initiation of a voluntary, industry-directed physical quality assurance program for radiotherapy facilities.

If substantial progress toward completion of the voluntary program, including a final completion date, has not been demonstrated at the end of two. years, the necessary studies should be initiated to determine whether a rulemaking is justified to require that l

radiotherapy facilities licensed by NRC have quality l assurance programs to ensure the accuracy of patient l doses. The programs shoul.d include such things as i independent verification of the activity of brachytherapy l sources before the sources are implanted.

(3) 10 CFR Part 35.21 should be amended to include the calibration of beam modifiers such as wedge filters, shaping filters, trays, etc.

3.2.3 Therapy Misadministrations Reported to NRC Since August 1984 Eight therapy misadministrations were reported to NRC from August 1984 to December 1985, and thus were not included in the AE0D case study discussed above. Four of the misadministrations occurred from August to December 1984 and four occurred in 1985. The types and causes of the misadministrations are given in Table 6.

Half of these misadministrations involved teletherapy treatment, with the primary cause being errors in dose calculations that were not detected prior to the beginning of treatment. The overtreatment of patients in these teletherapy events ranged from from 12% to 79%.

Two misadministrations since August 1984 involved the administration of ,

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iodine-131 for the treatment of hyperthyroidism. In one case, 12 microcuries was administered instead of 12 millicuries, as prescribed, because the dose calibrator was set for microcuries instead of millicuries. In the second case, the technologist failed to verify the activity of an iodine dose administered to a patient. The patient received a dose 50% greater than the prescribed dose. A review of these misadministrations revealed that they rasulted frcm procedural problems and/or the failure of licensees to assay patient doses prior to administration of the radiopharmaceutical.

The brachyth6rapy misadministration reported since August 1984 involved the overtreatment of a patient by 180% (5000 rads prescribed; 14,000 rads adminis-tered). Although there is some question as to the root cause of the event, independent verification of the dose calculation could have averted the i

misadministration.

One 1985 misadministration involved the use of a strontium-90 eye applicator on the wrong part of the eye. The eye was treated with 1000 rads of radiation (beta radiation). The licensee's report provided minimal information on the circumstances that led to the misadministration. This is the only report that AEOD has received of this type of misadministration. .

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TABLE 6 Therapy Misadministrations Reported to NRC August 1984-December 1985 Misadministration  % Difference in Number

• Treatment Dose Type ** Cause 27 +79% T Dosimetrist performed dose calculations based on the wrong prescription 28 +12% T Error in dose calculations 29 +26% T Error in dose calculations 30 +50% R The technologist failed to verify the activity of iodine-131 therapy dose 31 -1000% R Dose calibrator range or function switch set to wrong

. position 32 +35% T Error in dose calculations 33 +180% B Error in dose calculations 34 NA 0*** Unique error 9

• These numbers have been assigned to agree with the identifying numbers used in Appendix A.

• • T - Teletherapy R - Radiopharmaceutical B - Brachytherapy 0 - Other

• • • This misadministration involved a Sr-90 eye applicator.

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, In general, most of the therapy misadministrations reported to NRC following the completion of the AE0D case study on therapy misadministrations are of the same type and have the same causal factors as the misadministrations included in the case study. (The exception is the one reported misadministration involving a Sr-90 eye applicator.) It is believed that the analysis of therapy misadministrations presented in the AE0D case study apply to the teletherapy and brachytherapy misadministrations reported since August 1984.

3.3 Diagnostic Misadministrations 3.3.1 General Table 5 shows the annual number of diagnostic misadministrations by type. The number of licensees. reporting misadministrations, and the number of patients involved in the misadministrations. It can be seen that there were 1958 diagnostic misadministrations events that occurred between January 1981 and December 1985. The misadministrations involved 2257 patients.

3.3.2 Percent of NRC Licensees Reporting Misadministrations The data in Table 5 show that the number of licensees reporting one or more events annually ranges between 293 and 351. Since some licensees have submitted reports in more than one year, a separate tally was made of the total .

number of licensees reporting over the period. The tally showed that the 1958 reports of diagnostic misadministrations received by AE0D were submitted by 817 (34%) of the approximately 2400 NRC licensees authorized to perform diagnostic nuclear medicine studies. The percent of licensees reporting one

or more misadministrations is roughly linear from 1982 through 1985 (Table 7).

j About five percent of NRC licensees submit their first misadministration each year.

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s TABLE 7 Cumulative Percent of NRC Licensees Reporting One or More Medical Misadministrations Year Cumulative Fraction 1980 0 1981 13%

1982 22%

1983 27%

1984 30%

1985 34%

3.3.3 Licensees Reporting Multiple Misadministrations The distribution of the number of licenseer, reporting specific numbers of

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diagnosticmisadmidistrationsisgiveninTable8. It can be seen that 401, or about half of the 817 licensees reporting, reported a single misadminis-tration, and 426 reported two or more misadministrations for a total of 1456 reports. The maximum number of misadministrations reported by a single licensee is 18.

The number of misadministrations reported per year by a licensee, however, does not necessarily provide an indication of the licensee's performance telative to other licensees. A better perspective of licensee performance is obtained by including the licensee program size for licensees reporting multiple misadministrations.

A recent study by the Technologist Section of the Society of Nuclear Medicine showed that about 80% of the Nuclear Medicine facilities are located at i hospitals. The survey also showed that, although the annual number of l

diagnostic procedures (using radioisotopes) was a function of the number of i hospital beds, it was reasonably constant over a wide range of numbers of beds.

l Based on data contained in the study, factors relating the number of studies l per bed for a given hospital size were determined.

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s Size Number of Procedures

- (Number of Beds) Per Bed Per Year 0-99 10 100-199 9.0 200-299 8.5 300-399 7. 5 400-499 7.5 500-999 7.0

>1000 5 This relationship permits an estimate of the number of nuclear medicine studies performed annually once the size of the reporting institution is known [e.g., a hospital with 250 beds would perform approximately 2125 (250 x 8.5) procedures peryear]. This value can be used to determine the error rate for a specific institution and to compare error rates among institutions.

TABLE 8 Licensees Reporting Multiple Misadministrations

. 1981-1985 Number of Number of Total Number Licensees Reporting Reports Submitted of Reports 401 1 401 158 2 316 96 3 288 65 4 260 i 45 5 225 28 6 168 10 7 70 9 8 72 3 9 27 1 12 12 1 18 18 Total 817 75 1857 As noted in Section 1, the average error rate for all NRC licensees has been estimated to be 0.01%. To calculate or estimate the error rate for individual l

licensees, the data provided above, together with the hospital size, were used to estimate the error rate for a sample of hospitals that reported several misadministrations over the five year period. The maximum calculated rate for an individual licensee in the sample set was 0.1%.

t

(

m  ;

1 These error rates show that the highest error rate of a licensee experiencing several misadministrations over the five year period was an order of magnitude higher than the average error rate for all licensees. This errDP tate was still small. AE0D is preparing a case study of licensees who report multiple misadministrations to determine whether any actions by NRC are appropriate.

3.3.4 Misadministrations Involving the Administration of a Dose Ditrering from the Prescribed Dose by Greater than 50%

The data in Table 5 show that 86 (4%) of the diagnostic misadministrations reported involved the administration of a radiopharmaceutical dose that differed from the prescribed dose by greater than 50%. For most of the misadministrations, the administered dose exceeded the prescribed dose. Most of the misadministrations of this type involved the administration of from 50%

to 100% of the prescribed dose of a technetium-99m compound, although one misadministrationin~volvedtheadministrationofatechnetiumdosethatwasten times greater than the prescribed dose (200 millicuries vs. 20 millicuries).

A small but significant subset of these reports involved the administration of a therapy dose of iodine-131 where a diagnostic dose of iodine-131 or a

~

compound of technetium-99m was prescribed. Ten reports of this type were received over the five year period. These misadministrations typically involved events in which the technologist performed a whole body iodine scan on the patient, where the referring physician ordered a thyroid uptake or scan.

l The dose for whole body iodine scans is typically 1 to 5 millicuries; the typical dose for a thyroid uptake study or scan is 30 microcuries of iodine-131, or 5 to 10 mil 11 curies of technetium-99m. The "whole body iodine-131 scan" is the only diagnostic study where this large amount of iodine-131 is used.

The radiation dose to a patient is significantly higher if he is administered therapy doses of iodine-131 instead of the prescribed diagnostic dose of a radiopharmaceutical. For example, a patient prescribed a 5-millicurie dose of technetium-99m for a " thyroid scan" would receive 0.7 rads to the thyroid. A l

five millicurie dose of iodine-131 can produce a dose of 4000-9000 rads to the thyroid.  ;

l -_ _

s For administrations of iodine-131 where the potential exists for a patient to receive a high dose of radiation if the wrong study is done, there appears to l be a demonstrated need for more involvement in the process by the nuclear l medicine physician. The Office of Inspection and Enforcement issued an j Information Notice (IN-85-61), "Misadministrations to Patients Undergoin;<

Thyroid Scan," July 22, 1985 that addresses this problem. The discussion section of the notice states:

Checking the patient's identification and previous history before approving nuclear medicine procedures is very important, especially where a high dose to the patient will result from the procedure. It also is important for licensees to establish written procedures for dosage preparation and administration and to check the referring physician's written

, request before administering the dosage.

3.3.5 , Causes and Corrective Actions for Diagnostic Misadministrations Essentially all of the diagnostic misadministrations have human error as the root cause. The only cause of an event involving the wrong radiopharmaceutical that appears to warrant discussion is the receipt of a mislabeled radio-pharmaceutical from a radiopharmacy. Tracking the number of the reports over time is important since a pharmacy may supply several hospitals with the same mislabeled drug at the same time. The numer of events stemming from this cause by year are:

1981 24 1982 31 1983 15 1984 29 1985 16 Although nurses and other personnel may contribute to wrong patient events, the technologist preparing or administering the radiopharmaceutical appears to be the person responsible for essentially all misadministrations except those attributed to mislabeled doses received from radiopharmacies. The root cause of most of the misadministrations involving the wrong patient appear to have resulted from the technologist's failure to verify the identity of the patient and the type of nuclear medicine procedure ordered.

s The dominant corrective action proposed by licensees was retraining. Since the corrective actions and their effectiveness are licensee specific, a meaningful determination of whether corrective actions were effective would have to focus on the trend in misadministration rates at specific licensees that reported several misadministrations. Since the highest misadministration rate estimated for a sample of licensees was 0.1%, no detailed evaluation of these rates and the associated corrective actions has been made.

3.4 Findings

(1) Thirty-four (34) therapy misadministrations were reported to NRC during 1981-1985. The error rate per patient for teletherapy misadministrations is estimated to be 0.015%. No estimates of error rate for other types of therapy misadministration are available.- There is no clear trend in therapy misadministrations.

, The actions proposed in AE0D case study report AE0D/C505 should

. be effective in reducing the occurrence of the types of teletherapy and brachytherapy misadministrations reported.

.. (2) The overall error rate for diagnostic misadministrations per administration was estimated to be .01%. The maximum calculated error rate for a sample of licensees that reported several misadministrations over the five year period was 0.1%. All of the error rates were low.

(3) A few diagnostic misadministrations involved the administration of a therapy dose of iodine-131 instead of the prescribed diagnostic dose of a radiopharmaceutical (iodine-131, iodine-123, technetium-99m,etc.). These misadministrations, though few, can result in patients receiving over 1000 times more radiation to the thyroid than would be received if the correct dose were administered.

(4) The number of misadministrations involving the wrong radio-pharmaceuticals has not decreased substantially over time. The number of misadministrations involving the wrong patient has shown a decrease between 1981 and 1985. The net result is a slight decrease in the total number of reports / year.

s -

APPENDIX A

SUMMARY

DESCRIPTION OF THERAPY MISADMINISTRATIONS REPORTED Case 1:

An error was made in measuring wedge filter transmission factors. The filters are wedge-shaped lead blocks placed in path of the radiation beam to produce a defined gradient of radiation in the treatment field. The undertreatment of at least 53 of approximately 900 patients treated by teletherapy irradiation from July 1980 to August 30, 1983 resulted from the error. Most of the 53 cases were 10-15% below the prescribed dose; however, four cases were 30%

below the prescribed dose. In 38 cases the licensee still had contact with the patient and had noted three cases where cancers (neoplasms) had recurred.

The error was discovered during an annual output calibration measurement that included a check of all wedges used in the treatment of patients. A discrepancy was found between the July 7, 1980 calculated wedge filter

< transmission factors and the August 30, 1983 calculated factors. For example, the 60 degree angle wedge, which had a factor of 1.63 based on data and calculations from 1980 had been recalculated based on August 30, 1983 data to have a~ factor of 2.70. Therefore, the licensee's patients treated with this wedge received radiation doses less than those prescribed by the physician.

Case 2:

._ A patient was setup for cobalt-60 radiation therapy treatment to the right breast, when the left breast was the one with the carcinoma. The patient received one treatment of 200 rads. There was no apparent injury. The therapist was directly involved with the setup and notified the patient and the referring physician.

Case 3:

A patient scheduled for cobalt teletherapy treatment of 3000 rads was administered a dose of 3345 rads (11.5% overtreatment). The treatment period was from December 22 to January 6 of the next year (10 treatments). The error was discovered on March 10. The overtreatment occurred due to an error in calculating the time that the cobalt source was exposed.

Case 4:

i A treatment of 3000 rads to the midline of the brain in 12 equal fractions of l 250 rads each via two lateral beams was prescribed. The treatment time for each beam was' calculated to be 1.39 minutes.

The dosimetrist calculated the treatment time on the physics calculation sheet l and then entered it in pencil in the first treatment column on the daily treatment record sheet. The calculations were then checked by a physicist who initialed both the physics calculation sheet and the chart check column in the 1

s daily treatment record sheet. In the hospital's procedures, when a patient is treated for the first time, the treatment time and the doses which have been .

written in with pencil by the dosimetrist are ovemritten in ink by the I technologist who administers the treatment. )

In this case, the first treatment was administered for 1.89 minutes instead of 1.39 minutes. This mistake was then carried on for 10 more treatments.

The mistake was discovered after the eleventh treatment. The twelfth treatment was cancelled. The patient received 3753 rads instead of the prescribed 3000 rads.

Case 5:

A patient with widespread metastatic carcinoma of the breast was referred to therapy with a chief complaint of massive swelling of the left arm due to extensive disease in the left axilla. Treatment of the left axilla with cobalt teletherapy began on March 2. Treatment ended on April 20 after delivery of a

, total of 6173 rads.

The misadministratioh ~ involves the treatment exposure record. Initially, the prescribed treatment was reviewed daily, but early response led to a prescribed three-week treatment regime with a total dose of 4575. The response at the end

- of the three-week period was so favorable that additional treatment was prescribed by the radiotherapist. Treatment was stopped by the radiotherapist after a recorded tumor dose of 5373 with the patient doing well. It was later determined that there had been an arithmetical error made in the addition of the therapy segments and that the actual tumor dose delivered was 6173 rads to the axilla. This error was found by the physics division during the routine check of the record as the record was being retired following discharge of the patient.

Case 6:

A patient undergoing radiation therapy was administered a tumor dose of 5570

- rads instead of the prescribed tumor dose of 4070 rads. The error occurred because of an error in measuring the tumor depth. Before treatment was begun, the tumor depth was measured to the 16.5 cm and dose calculations were based on j this measurement. During the last of several subsequent patient followup visits after completion of therapy, the radiation oncologist remeasured the I

patient and found that the tumor depth should have been stated as 11.5 cm.

Case 7:

A patient, prescribed a dose of 4500 rads, was administered a dose in excess of 6000 rads. The misadministration occurred because the treatment depth to be used in the dose calculation was incorrectly entered on the patient's chart.

This was discovered as calculations were being prepared for a second treatment for the patient.

l f

Case 8:

A teletherapy misadministration resulted in administering about 2475 rads to a portion of a lung rather than the originally prescribed 1500-1800 rads. The original prescription called for administering 3000 rads to all sites of the initial disease in the lung. Because the therapist felt that the volume of lung involved could not tolerate the dose, he elected to reduce the area of lung to be irradiated after 1500-1800 rads had been administered. A filter block to reduce the area being irradiated was not inserted as intended by the i therapist, because the prescription had not been updated by the therapist before this phase of the treatment. The patient may have increased risk of pneumonitis.

Case 9:

A patient undergoing teletherapy' treatment to the right posterior chest was administered a radiation therapy dose of 3200 rads instead of the prescribed dose of 2000 rads. The treatment was administered in two treatments of 400 rads and three treatments of 800 rads. The misadministration apparently occurred because of a . combination of erroneous data from the treatment planning system computers and a miscalculation based on those data. The error was discovered when the calculations were rechecked after completion of the treatments.

Case 10:

- A patient scheduled for a 3000 rad cobalt-60 teletherapy treatment was administered a dose of 3614 rads. The patient treatment prescribed by the radiotherapist was 3000 rads minimum tumor dose to the patient's whole brain to

, be delivered in 10 fractions utilizing two lateral, pair-opposed cobalt-60 l teletherapy radiation fields. The misadministration was detected during the final dosimetry check by the physics department personnel who determined that the total dose delivered to the tumor was 3614 rads. On July 31 a hand calculation was performed correctly for the treatment of the patient who was to receive a total of 300 rads per day from two lateral fields. The hand-calculated treatment paramete9s were employed for two treatments, at which time a computer analysis was worked up for determining a more precise schedule for the remainder of the treatment. An error in converting from rads / day to minutes of exposure per day occurred at this point in the planning process on August 4. This incorrect time was used through the remaining eight days of treatment.

Case 11:

A patient undergoing cobalt-60 teletherapy treatment was administered a dose of 8100 rads instead of the 6500 rads dose intended. The error in treatment was detected during a revision of the patient's treatment time for another procedure by a radiation dosimetrist. At the time the error was detected, the patient's treatment record ' ndicated i that a cumulative dose of 4860 rads at 180 rads / fraction in 27 fractions had been delivered, whereas the patient had actually received 8100 rads at 300 rads / fraction in 27 fractions. The treatment

s plan for this patient was devised at one hospital and transferred to a second hospital where the dose was administered. Calculation of the treatment time requires the dosimetrist or physicist to obtain the calibrated dose rate for the particular treatment machine from a table of dose rate vs. field size.

Tables for three machines are kept in the dosimetry work area in a single binder separated by dividers. The error occurred because the dosimetrist obtained the dose rate from the table for a machine different from the one to be used and the physicist reviewing the treatment plan did not detect the error.

Case 12:

A patient undergoing teletherapy treatment of the brain received a dose of 8700 rads instead of the prescribed dose of 6000 rads. The treatment prescribed for the patient was 200 rads total dose per day to the midline of the brain via two lateral radiation beams. Thus, each lateral field should have contributed 100 rads per day total dose delivered to the midline of the brain. The patient

- received 15 treatments at an actual rate of 400 rads / day (200 rads / day per field) for a cumulative dose of 6000 rads. The patient developed erythema (severe reddening of the skin) during the treatment course. Because this.

condition was more severe than anticipated, the attending physician reduced the prescribed dose to 150 rads per treatment after the fifteenth treatment. A second dosimetrist calculated a new exposure time, repeating the original error. The dosimetrist who calculated the original treatment dose erred in calculating the exposure time so that 200 rads was administered to each side of the head (twice the intended amount of radiation per treatment).

~

The severity of the erythema continued to increase and after nine treatments at the reduced level the physician asked for a review of the dose calculations.

The recheck identified the error and the treatment was stopped. The patient had received a total of 8700 rads which was 45% more than the prescribed dose.

Case 13:

A patient undergoing teletherapy radiation therapy treatment of the brain with a prescribed dose of 4000 rads received a 6400 rad dose to the treatment area.

The prescribed dose was to be administered from both the front and the side of the head (100 rads per side). Hospital therapy personnel erroneously calcu-lated the exposure time so that the patient received 200 rads from the front and 200 rads from the side. The total exposure for each treatment was therefore twice that intended.

The patient received 16 treatments at the elevated level for a total of 6400 rads compared to the intended total of 4000 rads. The error was found during a review of the patient's treatment record by the tnerapist.

The licensee had quality control procedures to check the exposure calculations, but the checks apparently failed to detect the error in this case in a timely manner.

l s l

l Case 14:

A physician initially gave an oral prescription for 600 rads / treatment times three treatments. He later signed a written prescription calling for 300 rads to be delivered in five treatments. Confusion of the two prescriptions resulted in a treatment plan for 600 rads for five treatments. The physicist I who had checked the arithmetic accuracy of the dose calculations for the oral prescription transferred the data from these calculations to the patient treatment sheet.

Case 15:

A patient scheduled for cobalt-60 teletherapy treatment (whole brain irradiation) was administered a dose of 6776 rads instead of a prescribed dose of 6000 rads. The original calculations called for a treatment time to each field (treatment utilizing opposed lateral fields) of 1 minute 58 seconds to deliver 100 rads to the mid sagittal plane. For this exposure time, the delivered dose was actually 154 rads to the mid-sagittal plane from each field, resulting in a daily misadministration error of approximately 50%. The original dosimetry _w_as done by a technologist on the cobalt unit. The technologist initiated the calculation which was subsequently checked and initialed by the resident physicist. The physicist reviewed the dosimetry and ongoing treatment record four times at two-week intervals (a standard of the licensee's procedure). After 22 treatments and a projected dose of 4400 rads to the mid-sagittal plane, the patient exhibited severe scalp reaction.

Because of this, the dosimetry was rechecked by the physicist and no error was perceived. The treatment was halted. Three weeks later when the patient's

,_ scalp reaction had subsided, she returned to continue treatment, at which point the chief technologist reviewed the dosimetry and pointed out an error in the original dosimetry. Treatment had begun on April 22, the error was discovered on June 12.

Case 16:

A teletherapy misadministration to the mediastinal area of a young male Hodgkin's disease patient resulted in an overexposure of about 11%. The prescribed dose was 4000 rads in 27 treatments plus 500 rads in three treatments. The latter was misread as 500 rads times three treatments, so that the patient received 5500 rads. The radiotherapist does not foresee any adverse affects to the patient because the spinal cord did not receive more than 4500 rads.

Case 17:

A patient undergoing both internal and external radiation treatment for cervical cancer using teletherapy and brachytherapy methods was administered doses of radiation (to two treatment areas) from brachytherapy sources that were 21% and 37% higher than planned or prescribed. The total' treatment dose from external and internal irradiation was 3.5% and 13% higher to the affected areas than prescribed. The overtreatment resulted from the brachytherapy loading device (applicator) being loaded with 17.4 mg radium-equivalent sources instead of 11.8 mg radium-equivalent.

nls

s

- Case 18:

A patient undergoing cesium-137 brachytherapy treatment was administered a dose of 12,000 rads to the uterus during a treatment period from April 9 to April 12. The prescribed total dose was 4000 rads. The error was caused when the wrong activity sources were loaded in a vaginal applicator. The prescribed loading of sources for the brachytherapy application was one 9.9 mg radium-equivalent source and three 6.3 mg radium-equivalent sources. Three 20.3 mg radium-equivalent sources were loaded instead of the prescribed three 6.3 mg radium-equivalent sources. The source loading was performed by a registered therapy technologist who was being trained as a dcsimetrist. The error was discovered by the physicist as the sources were being replaced in the storage safe upon removal from the patient. The physicist noted that the source color coding did not match the color coding for the sources in the prescription (20.3 mg radium-equivalent sources are color coded white., 6.3 mg radium-equivalent sources ar,e color coded purple). An examination of the patient three days after removal of the sources revealed no unexpected abnormalities in the vagina.

Case 19: -

A patient with carcinoma of the cervix underwent intracavitary cesium applica-

~ tion with a Fletcher Suit tandem and ovoids (four sources in the tandem and one source in each ovoid (20 mg radium equivalent in each saurce). The applicator was removed after 23.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />. A routine radiation protection survey of the room immediately following removal of the sources showed that a source was present in the room. The source was subsequently found in the patient's bed.

It was believed that the source had slipped out of the tandem on removal of the afterloading device and fell underneath the patient. Upon that patient's return for additional treatment four weeks later, it was discovered that a lesion (approximately 2 cm x 3 cm) with erythema and dry desquamation was present on her buttock.

Case 20:

A patient undergoing therapy treatment of vaginal cuff following a hysterectomy for an adenocarcinoma of the endometrium was administered a dose of 1000 rads instead of a prescribed dose of 3825 rads. The treatment used two cesium-137 sources of 30 mg radium-equivalent and 15 mg radium equivalent loaded in an applicator. The estimated lower dose received was based on a review of the source placement in the applicator following completion of the treatment. The therapist believes that two radioactive sources were not placed exactly at the intended location in the applicator. While loading the sources in the applicator which had been placed in the vagina, the radiation therapist experienced some difficulty inserting the active sources. The applicator was examined and it was found that the dome part of the applicator had changed its shape from circular to somewhat elliptical. This made the plastic tube source

, carrier difficult to insert into the applicator.

s s I Case 21:

A patient undergoing brachytherapy treatment with iridium-192 was administered a dose to the treatment area that was 12% greater than the prescribed dose.

The misadministration occurred because of a delay in determining the precise location of the implant in the tumor volume. This led to an underestimate of the dose rate to the treatment area.

Case 22:

A patient with widely disseminated malignant melanoma with extensive brain metastases developed malignant ascites. In an attempt to help alleviate the symptoms, on May 22 an intra-abdominal injection of 13.4 millicuries of phosphorus-32 in the form of chromic phosphate was ordered from the radio-pharmaceutical company. Review of records on June 5 revealed the actual injection consisted of the correct amount of phosphorus-32, but in the sodium phosphate form.

The chemical significance of the use of sodium phosphate instead of chromic phosphate results from the greater solubility of the sodium form as compared to the insolubility of the latter. In the intended treatment with P-32 chromic phosphate, a substantial amount of the radioactive P-32 is retained within the

_ abdominal cavity until decay. With the use of sodium phosphate, some of the P-32 will be eliminated from the body and some will enter the bloodstream.

The principal clinical effects of the use of P-32 as sodium phosphate are a somewhat reduced dose to the abdominal areas and an increased dose to the bone marrow. Any effects on the bone marrow would appear several months after the dose as abnormal blood parameters.

Case 23:

A patient with a diagnosis of toxic multinodular goiter was prescribed 29.9 mci

of I-131 to be administered on February 22. On that date, the patient was I

administered two capsules of I-131, with one capsule assayed by the supplier as l

20 mci and the other capsule assayed as 8 mci, with the assay time for botn

capsules being 12 noon on February 26. While written procedures require the

! dose to be calculated on a dose sheet and the activity of the radioisotope to l

be measured in a dose calibrator before being administered to the patient, j neither procedure was followed. The calculation procedure was not followed because each of the technologists assumed another technician had performed the dose calculation and had corrected the activity to February 22. The activity of the I-131 capsules was not measured in the dose calibrator because of the technologists' confusion in the requirements to calibrate I-131 therapy doses.

, As a result of these two errors, the patient was given 39.5 mci of I-131

instead of the prescribed dose of 29.9 mci.

Case 24:

1 On September 24, a patient scheduled to receive a therapeutic dose of 5.4 millicuries of iodine-131 in capsule form received a capsule of 0.392 milli-curie activity. The administering technologist took the capsule from a container containing a capsule which had been assayed at 5.2 millicuries on

s August 25, and was being stored for decay prior to disposal. The technologist overlooked the unmarked container that contained the capsule intended for the patient.

Case 25:

The wrong patient received an 8 millicurie dose of iodine-131 for hyper-thyroidism. This patient (who did not speak English) was scheduled for thyroid evaluation as an outpatient in the nuclear medicine department on March 23.

She was misidentified as another patient (who also did not speak English) who was scheduled for hyperthyroid treatment on March 24. The language barrier was cited by the hospital as the principal reason for the mistake. The error was discovered when the correct patient reported to nuclear medicine on March 24. The misadministered patient was contacted on that date and returned to the hospital the morning of March 25. A thyroid scan was performed and she was instructed to start taking Lugol's solution orally for the next five days.

- Case 26:

~~

Patient received a dose of iodine-131 for hyperthyroid treatment that exceeded the prescribed dose by more than 10%.

Case 27:

A patient undergoing teletherapy treatment to the left shoulder with a

._ prescribed dose of 3500 rads in 10 treatments was administered a dose of 4432 rads in 10 treatments. This misadministration resulted from errors in the machine setting calculations (dose calculations). The calculations were not rechecked as required by licensee procedures within a few days of the beginning of the therapy.

Case 28:

An error in calculating the machine on-time led to a patient undergoing tele-therapy treatment receiving a radiation dose that differed from the prescribed dose by more than 10%. The prescribed dose was 66 Gray (6600 rads) and the administered dose was 74 Gray (7400 rads). The licensee's report indicated that the machine on-time calculations were not independently verified as required by procedures.

Case 29:

A patient undergoing the second of two courses of teletherapy treatment (therapy to ninth and tenth ribs) received a dose of 3584 rads instead of the prescribed dose of 2000 rads.

The first course of therapy was 2000 rads in five treatments and was completed without any problems. The second course of treatment prescribed was 2000 rads to be delivered in 10 treatments. However, when the treatment dose for the second treatment course was calculated, the dosimetrist assumed that the

prescription was the same as the earlier one. The dosimetrist failed to prepare new calculations as required by hospital procedures but relied on verbal communications and only decay-corrected the output from the first treatment. As a result the patient's treatment was begun at twice the prescribed rate. The licensee's procedures required that a new requisition be completed and new calculations be done. This error was not discovered until the patient had received 3584 rads in the second course of therapy when one of the treatment technologists noticed that the delivered dose differed from the prescribed dose by greater than 10%.

Case 30:

A patient scheduled to receive a 10 millicurie dose of iodine-131 for treatment of hyperthyroidism was administered a dose of 15 millicuries. A 10 millicurie iodine-131 dose had been ordered for this patient and a 5 millicurie dose for another patient. The Nuclear Pharmacy dispensed both patients doses in the

~

same bottle (three 5 millicurie capsules). When the first patient arrived, the technologist opened the bottle containing the capsules and administered the capsules without verifying the activity or the number of capsules. The patient was administered three 5 millicurie iodine-131 capsules.

Case 31:

A patient for whom a 12 millicurie dose of iodine-131 was prescribed for hyperthyroid treatment, was administered a 12 microcuries dose of iodine. The technologist mixed-up the iodine-131 dose that was prescribed for the patient

~ with an iodine-131 dose being stored for decay (12 microcuries dose). The technologist then assayed the dose with the dose calibrator set for microcuries instead of millicuries.

Case 32:

A patient undergoing teletherapy treatment was administered a dose of 4065 CGY instead of the prescribed dose of 3000 CGY as prescribed. The treatment was parallel opposed fields for treatment of the brain. The treatment time to each field was 1 minute longer than prescribed. The error while detected during a chart review was missed during the initial chart review for the patient.

Case 33:

An NRC licensee reported that a patient had received a 14,000 rad dose to the left lung instead of the prescribed 5000 rad dose. The patient was to be i treated for lung cancer using implanted iridium-192 radiation sources to i deliver a prescribed radiation dose of 5000 rads to the left lung. In planning the treatment, the radiation physicist determined that 12 seeds (tiny sealed radiation sources), each containing 10 millicuries of iridium-192, would be sufficient for the treatment. The radiation physicist stated that she did not calculate the treatment time needed for delivering the prescribed dose, l

s but the physician on the case stated that a 50-hour treatment period had been proposed by the physicist.

Later on the day of the implant, following discussions between the physician and the radiation physicist, the radiation physicist realized that no calculations had been performed to determine the treatment period. The physicist then determined that 14000 rad had been delivered to the left lung at that time, and the iridium seeds were promptly removed.

At the time of the event, the hospital had no quality assurance procedures designed to verify the accuracy of radiation treatment plans to assure that they would deliver the prescribed radiation dosage. The hospital has implemented revised treatment procedures requiring that written calculations to determine a radiation therapy plan be performed prior to the initiation of a treatment and that the calculations be reviewed by a second qualified individual. The procedures were submitted to the NRC. The licensee's Medical Review Board has approved the procedures.

Case 34: . . _

The medill limbal area of a patient's eye was treated with 1000 rads of Sr-90 radiation (Sr-90 eye applicator). The prescribed area for treatment was the

' lateral limbal area of the right eye. The licensee indicated that no compli-cations are anticipated to result from the treatment.

O

s s APPENDIX B DIAGNOSTIC MISADMINISTRATIONS REPORTED TO NRC 1981-1985 Type of Misadministration: Wrong Radiopharmaceutical Number of Reports Year Cause Code 1981 1982 1983 1984 1985 11 25 31 15 29 16 12 36 52 49 70 71 13 25 25 24 35 42 14 27 13 22 23 18 15 20 10 12 10 20

, 16 16 29 17 27 31 17 10 11 9 4 11 98 110 96 67 56 61

- 99 24 18 27 22 24 Corrective Action Code C1 11 10 9 12 C2 45 25 31 43 C3 C4 108 123 115 108 C5 17 10 18 11 C6 14 1 2 4 C7 15 21 12 9 i

98 83 83 53 86 99 3

$!Z Cause Codes:

11 -

Radiopharmaceutical received from radiopharmacy was mislabeled 12 - Mix-up of radiopharmaceutical doses stored in lead pigs 13 -

Physician's order misinterpreted 14 -

Wrong reagent kit used to prepare dose 15 -

Lead pig or syringes were mislabeled 16 -

Mix-up of syringes containing radiopharmaceuticals 17 - Nuclear medicine requisition was not checked 98 -

Insufficient information 99 -

Other

s 34 -

Corrective Action Code:

C1 - Implement new procedures requiring technologist to check patient's chart for physician order C2 -

Implement new radiopharmaceutical labeling and handling procedures, e.g., color coding, segregation of radiopharmaceuticals, etc.

C3 - Implement new procedures for patient identification, i.e., ask patient to state or write name, check patient SSAN, use of secondary identification, as well as patient ID bracelet C4 - Reinstruct personnel C5 - Reprimand technologist or other personnel C6 - Improve supervision of personnel C7 - Not specified 98 -

Insufficient information 99 -

Other

m. =

6 e

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