ML20207P684

AEOD/N701, Diagnostic Misadministrations Involving Administration of Mci Amounts of I-131, Engineering Evaluation Rept

ML20207P684
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Issue date:	01/14/1987
From:	Pettijohn S NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD)
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ML20207P683	List: ML20207P682 ML20207P684
References
FRN-52FR36942, RULE-PR-35, TASK-AE, TASK-N701 AC65-1-032, AC65-1-32, AC65-32, AEOD-N701, NUDOCS 8701200052
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AE0D ENGINEERING EVALUATION REPORT LICENSEES: Various EE REPORT NO.: AE0D/N701 EVENT DATES: Various DATE: 01/14/87

REFERENCES:

See Footnotes EVALUATOR / CONTACT: S. Pettijohn X28348

SUBJECT:

DIAGNOSTIC MISADMINISTRATIONS INVOLVING THE ADMINISTRATION OF MILLICURIE AMOUNTS OF 10 DINE-131 INTRODUCTION As a result of a number of serious misadministrations involving radiation therapy in the 1970s, and to assure the complete and consistent reporting of 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 regula-tions did not define the occurrence of a misadministration to be a violation of any NRC regulation. ,

I Nuclear medicine is defined as that speciality in the practice of medicine I dealing with the diagnostic, therapeutic (exclusive of sealed sources), and I investigative use of radionuclides. Therapeutic radiology (radiation therapy) is that branch of radiology which deals with the therapeutic application of ionizing radiation, including Roentgen and gamma rays, as well as particulate I radiation from whatever source, including artificially and naturally radio-active, as well as X-ray generators and particle accelerators. Diagnostic misadministration, as used in NRC regulations, refers to the misadministration of radioisotopes during diagnostic procedures (e.g., thyroid scans, bone scans,etc.). 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 misadministration 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 administration other than that intended by the prescribing physician; (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

• Definition from Nuclear Medicine Therapy and Techniques, Edited by Donald R. Bernier, C.N.M.T., James K. Langan, C.N.M.T., and L. David Wells, C.N.M.T., The C.V. Mosby Company, St. Louis, Toronto, London 1981.

8701200052 870114 PDR ORG TEXD PDR

m . __ __ .. _ _.. . ._ _ _ _ _ .__ .. _.

a

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~(f) a therapeutic radiation dose from a sealed source such that errors in the source calibration, time of exposure, and treat-i ment 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 Office of Inspection and Enforcement (IE) issued an Information Notice i

(IN-85-61)datedJuly 22, 1985, titled "Misadministrations to Patients Undergoing Thyroid Scans," that addressed the occurrence of diagnostic misadministrations involving the administration of millicurie amounts of iodine-131 to patients. The IN was developed from information compiled by us and forwarded infonnally to them. Following our tracking and review of reports of several additional misadministrations of this type over the last year, AE00

, decided to evaluate the safety implications of this type of misadministration and assess whether action should be taken to minimize the occurrence of this type of misadministration.

This engineering evaluation report documents our review of 14 reports of diagnostic misadministrations, each of which involved the administration of

-a 1-10 millicurie dosage of iodine-131 to a patient, whereas the prescribed radiopharmaceutical was either iodine-131 (6-300 microcuries), iodine-123 (150-400 microcuries), technetium-99m (0.1-10 millicuries), or technetium-99m methylenedisphosphonate (20 millicuries). The average radiation dose

, (calculated) to the thyroid (critical organ) of the patient involved in a

~

misadministration was over 80 times the average radiation dose (calculated) that the patient would have received if the correct radiopharmaceutical and/or dosage had been administered.  :

The 14 diagnostic misadministrations evaluated in this report were received j by NRC during the period January 1982 through June 1986, a 41/2-year period.*

This represents an annual rate of three misadministrations of this gype. The error rate for these misadministrations is calculated to be 6 x 10~ based on an estimate of 500,000 thyroid scans per year.** This error rate is about i

a factor of 100 smaller than the error rate found for diagnostic misadminis-i trations*** reported to NRC. However, similar to therapy misadministrations, i the significance of diagnostic misadministrations involving the administration l

t

• The 14 reports were identified from a search of the AE00 misadministra-l tion database for all reports of diagnostic misadministrations that involved the administration of iodine-131 where the administered amount exceeded the prescribed amount by greater than 50%.  !

! **From a survey of data on the in vivo use of radioisotopes for the third j quarter of 1984 compiled by Medical Marketing, Inc.

***AE0D report AE0D/C505, dated December 1985, which documents an AE0D Case Study on Therapy Misadministrations Reported to NRC Pursuant to 10 CFR 35.42,shows(onpage the error rate per patient for therapy misadminis-

. trations to be 2 x 10-i i

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3 ,

of millicurm amounts of iodine-131 to patients stems from the fact that each misadministration had the potential to result in severe health effects on the patient involved.

Additional factors that contribute to the significance of the reported misadministrations are that:

Six* of the 14 misadministration cases involved a substantial degradation to the protection of public health and safety as defined in the Commission's criteria for abnomal occurrences related to misadministrations and thus, were reported in the Quarterly Report to Congress on Abnomal Occurrences.

The types of errors that led to most of the misadministrations are similar to errors found for diagnostic misadministrations in general, indicating that there may be a significant potential for these types of errors to occur and thus continue to occur in the future.

ANALYSIS OF THE EVENTS

Background

For diagnostic nuclear medicine studies,** the technologist in general uses a radiopharmaceutical/ dosage schedule approved by the nuclear medicine physician in determining the correct dosage of a radiopharmaceutical to administer for a particular nuclear medicine study. This is in contrast to procedures normally used in radiation therapy, whereby the radiation therapy dose is calculated specifically for each patient. The dosage schedule normally provides for a range of doses to account for variations in a patient's age, weight, etc. For example, a typical dosage for a thyroid uptake study may be specified as 20 microcuries of iodine-131 if the patient is an adult; however, if the patient is a child the dosage specified would generally be less. A dosage (i.e., the amount of the radionuclide in microcuries, millicuries, etc.) may not be explicitly specified by the dosage schedule for each patient type but rather a formula may be specified for use in determining the dosage for a particular patient type.

• 0nly six of the misadministrations were reported as abnormal occurrences because eight of the misadministrations occurred before the adoption of the present criteria for determining whether a misadministration is an abnormal occurrence. These eight misadministrations meet the present abnormal occurrence reporting criteria for misadministrations.

• • Diagnostic nuclear medicine studies as used in this report refers to the type of diagnostic procedure involving the investigative use of radio-nuclides(i.e.,bonescans,thyroidscans,etc.).

,,,-n.- - - . . . , . . . , . , _ - . , , - . - - - - , , - , -. _ . - , , , , , . , . , . - - . , , . . . - - - . . - . -

. 4 The referring physician generally specifies the particular diagnostic study to be perforrred. The required dosage to be administered to the patient is then determined from the schedule for the prescribed diagnostic nuclear medicine study. As noted above, the schedule usually specifies both the radiopharmaceutical and the dosage of the radiopharmaceutical to be adminis-te red. This means that the technologist can perform the administration and irraging part of most diagnostic nuclear medicine studies without the direct intervention of a nuclear medicine physician. The interpretation of the nuclear medicine study results is performed by the nuclear medicine physician.

Table I shows the radiation dose to a patient that results from several common diagnostic nuclear medicine studies. From the table, we see that the radiation dose to a patient's thyroid (the critical organ) from an " iodine-131 whole body scan,"* 800-8000 rad, is substantially greater than the critical organ dose from other diagnostic studies (e.g., liver scan or lung scan).

Generally, the radiation dose to a patient (critical organ) that results from a misadministration caused by the administration of the wrong diagnostic study, say a lung scan rather than liver scan, is generally of the order of I-2 rads. The radiation dose to a patient's thyroid that results from a misadministration involving a "iodinc-131 whole body scan" instead of a thyroid scan can be several thousand rads.

From Table 1, we see that the radiation dose to a patient's thyroid undergoing an iodine-131 whole body scan is in the same dose range as for a patient undergoing therapy for hyperthyroidism (state of increased thyroid function) where the radiation dose can range from 4000 rads to 24000 rads.

• Iodine-131 whole body (or total) scans are performed on patients with diagnosed thyroid cancer for the purpose of searching for metastatic deposits of functional thyroid cancers throughout the body. The dosage of iodine-131 administered for whole body scans for the misadministrations included in this report ranged from 1 to 10 millicuries.

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= TABLE 1 Typical Administered Activity and Corresponding Radiation Dose to the Patient for Several Comon Nuclear Medicine Studies *

- Radiation Estimated Dose to Radiation

- Critical Dose to Nuclear Medicine Administrated Critical Organ (mrad / Critical microcurie) Organ (Rads)

~

Study Activity (mci) Organ

Bone Scan Technetium-99m methylene-diphosphonate (MDP) 15-20 Bladder Wall -0.051 0.76-1.02 Liver / Spleen Scan n Technetium-99m-sulfur colloid 4-6 Liver 0.340 1.36-2.04 4

Lu'no Scan Technetium-99m I- macroaggregated albumin 4 Lung 0.290 1.16

Xenon-131 gas 15 Lung 0.016 .24 Thyroid Uptake Iodine-123 (iodide) .010 .020 Thyroid 7.5 .075 .15 Iodine-131(iodide)- .006 Thyroid 800 4.8 Thyroid Scan i Technetium-99m i (Sodium Pertechnetate) 5-10 Stomach Wall 0.025 .125 .25 Iodine-123(iodide) .100 .400 Thyroid 7.5 .75-3 Iodine-131 (iodide) .030 Thyroid 800 24

(.03 .2)** (24-160)

Iodine-131 Whole Body Scan

! Iodine-131(iodide) 1-10 Thyroid 800 800-8000 l Hyperthyroidism i Treatment ***

l Iodine-131(iodide) 5-30 Thyroid 800 4000-24000 i

• Data derived from the National Council on Radiation Protection and Measurements (NCRP) Report 70 issued June 1, 1982; and Nuclear Medicine Technology and

Techniques, Edited by Donald R. Bernier, C.N.M.T. , James K. Langan, C.N.M.T. ,

i- and L. David Wells, C.N.M.T. , The C.V. Mosby Company, St. Louis, Toronto, L London 1981, f

L **Although data from the above reference show the iodine-131 dosage for a

thyroid scan to be 30 microcuries, the dosages administered in the misadministration cases ranged from 30-200 microcuries.

• • • Included for comparison.

. 6 Description of the Events The 14 misadministration events involved the administration te patients sched-uled for diagnostic nuclear medicine studies (thyroid scan, thyroid uptake, and bone scan), amounts of iodine-131 that normally would be administered for the diagnostic study "whole body iodine scan." Table 2 shows the prescribed and administered radiopharmaceutical and dosage for each of the misadminis-trations. From the table we see that the misadministered dosage of iodine-131 ranged from 1 millicurie to 10 millicuries, with an average dosage of 4.7 millicuries. The estimated radiation dose to the thyroid of patients ranged from 800-8000 rads, with the average dose being 3760.* The estimates of the radiation dose in ICRP Report No. 70 are based on a maximum thyroid uptake of 15%. The actual radiation dose to individual patients will vary depending on a number of factors such as, the accuracy of the assay of the administered iodine-131 dosage, the weight of the thyroid,** thyroid condition that might affect the uptake of iodine-131,*** and whether thyroid blocking agents are administered to the patient after the discovery of the misadministration, etc.

We are not able in this report to make a quantitative assessment of the health effects on the specific patients involved in the misadministrations, since we did not have available for review the medical evaluations for the patient.

• International Connission on Radiological Protection (ICRP) Report No. 70, issued June 1982 (see Table 1 above) shows that the radiation dose to the thyroid from iodine-131 is approximately 800 millirads/ microcurie of iodine-131 administered.

• • The weight of the thyroid and consequently the iodine uptake varies

, with age and between different patients.

• • • Thyroid uptake of iodine of over 55% is suggestive of hyperthyroidism (state of increased thyroid function) values of less than 20% are indicative of hypothyroidism (state of decreased thyroid function).

Handbook of Radiation Measurement and Protection, Editor, Allen Brodsky, CRC Press, Inc., Boca Raton, Florida.

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7 TABLE 2 Prescribed and Administered Radiopharmaceutical and Dosage for Each Misadministration Prescribed Study Dosage Administered Study Dosage Case # 'Radiopharmaceutical (mci) Radiopharmaceutical (mci)

I thyroid scan 0.40 I-131 whole body scan 10.0 I-123 I-131 2 thyroid scan 0.10 1-131 whole body scan 5.0 Tc-99m I-131 3 thyroid uptake scan 0.08 I-131 whole body scan 5.6 I-131 I-131 4 thyroid uptake scan 0.15 I-131 whole body scan 5.0 I-123 J-131 5 whole body bone scan 20.0 I-131 whole body scan 10.0 Tc-99m MDP I-131 l 6 thyroid scan 0.05 not specified 3.09 I-131 I-131 7 thyroid uptake 0.015 not specified 4.9 l-131 1-131 8 thyroid scan (including 0.10 thyroid scan (including 4.9 the chest area) the chest area)

I-131 1-131 9 thyroid scan (including 0.03 thyroid scan (including 2.0 the chest area) the chest area)

I-131 I-131 10 thyroid scan (including 0.10 thyroid scan (including 1.0 the chest area) the chest area)

I-131 I-131 11 thyroid scan ft/A* I-131 whole body scan 5.0 Tc-99m I-131 12 thyroid scan 0.20 thyroid scan 1.0 I-131 1-131 13 I-131 whole body scan 6.0 I-131 whole body scan 6.0 I-131 I-131 14 thyroid scan 0.03 not specified 5.6 I-131 I.-131 1

• Information not available. The normal dosage is 5-10 millicuries.

l l

a We have tabulated in Table 3 the information provided by licensees on the ,

estimated effect of the misadministration on the patient. The estimated health l effects documented in Table 3 suggest that some patients could be expected to suffer some deleterious effects from the misadministrations including partial loss of thyroid function.

Causes of the Misadministratiegl Table 4 lists the primary cause and applicable contributing factor (s) for 13 of the 14 misadministrations. For one misadministration (14)* the licensee's report did not specify the cause of the misadministration.

From a review of Table 4 we see that:

The cause of seven (1,2,3,4,5,6,7) of the 14 misadministrations (50%) can be ascribed to the referring physician's order being misinterpreted by or miscommunicated to the technologist.

The cause of three (8,9,10) of the 14 misadministrations (21%)

can be ascribed to the technologist not being familiar with the iodine-131 dosage requirements for thyroid scan procedures that p involve scanning the chest area.

The cause of three (11,12,13) of the 14 misadministrations (21%)

can be ascribed to miscellaneous causes: a patient's identity was not verified before administerin[ the iodine dosage; the technologist picked up the wrong iodine-131 capsule and did not assay it prior to admin stering it to the patient; and the nuclear medicine physician or radiologist war not aware that part of the i

patient's thyroid was intact before prescribing the amount of iodine to administer to the patient for a whole body fodine-131 scan.

These causes are discussed in more detail below.

1. Misinterpretation /Miscommunication of the Referring Physician's Orders.

The seven misadministrations (1,2,3,4,5,6,7) in this group involved cases where the patient was administered a dosage of iodine-131 for a nuclear medicine study that was not ordered by the referring physician. Of the seven misadministrations, six (1,2,3,4,6,7) involved patients being admin-istered dosages of iodine-131 normally prescribed for an iodine-131 whole body scan whereas the patient's physician had ordered a thyroid scan. One misadministration (5) involved a patient being administered a dosage of iodine-131 normally prescribed for an iodine-131 whole body scan whereas the patient's physician had ordered a bone scan.

• These number (s) refer to case numbers in Table 4 and Appendix A.

TABLE 3 -

Summary Data on Estimated Health Effects Reported by 1.ihensees in Misadministration Reports I

Prescribed Admin. Health Effect Case Prescribed Dosage Admin. Dosage Time of Thyroid Estimated by No. Radiopharm (mci) Radiopha rm (mci) Discovery Block Licensee 1 I-123 0.4 I-131 10 When Scanning Yes Border Hypothyroidism 2 Tc-99m 0.1 I-131 5 After scan No 50% Hypothyroidism 3 I-131 0.08 I-131 5.6 N/A* No None Specified 4 I-123 0.15 I-131 5 When Scanning No None Specified 5 Tc-99m MDP 20 I-131 10 When Scanning Yes Probability of Hypothyroidism e

6 I-131 0.05 I-131 3.09 N/A* No Degree of Impairment 7 I-131 0.015 I-131 4.98 N/A* No None Specified 8 I-131 0.10 I-131 4.9 When Scanning Yes Degree of Impairment 9 I-131 0.03 I-131 2 N/A* No N/A*

10 I-131 0.1 1-131 1 When Scanning No Mininal 11 Tc-99m N/A* I-131 5 Immediately Yes None 12 I-131 0.2 I-131 1 When Scanning No No Measurable Amount 13 I-131 6 I-131 6 N/A No None 14 I-131 0.03 I-131 5.6 N/A* No None

• Information was not available.

- 10 TABLE 4 Primary Cause and Contributing Factors for Each Misadministration Study Radiopharmaceutical Case (dosage)

No. Prescribed Administered Cause Contributing Factors 1 thyroid scan I-131 whole The term " iodine 1) The order was made I-123 body scan scan" used by the by telephone.

(0.4 mci) I-131 referring physician's 2) The technologist (10 mci) office in ordering administered the the thyroid scan in iodine without a the licensee's written prescrip-terminology meant tion.

" iodine-131 whole body scan" 2 thyroid scan I-131 whole The term " iodine 1) The order was Tc-99m body scan scan" used by the made by telephone.

(0.1mC1) I-131 referring physician's 2) The technologist (5.0mC1) office in ordering administered the the thyroid scan in iodine without a the licensee's written prescrip-terminology meant tion.

" iodine-131 whole body scan" 3 thyroid uptake / I-131 whole The nursing station None scan body scan misinterpreted the I-131 I-131 physician's order for (0.080 mci) (5.6 mC1) an " iodine thyroid uptake and scan" to be an order for an "I-131 whole body scan" 4 thyroidupNke/ I-131 whole The nuclear medicine The prescription scan body se an physician mistakenly was transmitted to I-123 I-131 prescribed a dosage the radiopharmacy (0.15 mci) (5.0 mci) of 150 microcuries verbally, of I-131 instead of of I-123 for a thyroid uptake and ecan.

This prescription was transmitted verbally to the hospital radiopharmacy where it was apparently misinterpreted as a prescription for a I-131 whole body scan

11 TABLE 4 (Continued) l Primary Cause and Contributing Factors for Each Hisadministration Study Radiopharmaceutical Case (dosage)

No. Prescribed Administered Cause Contributing Factors 5 whole body I-131 whole The patient was 1) The patient was bone scan body scan mistakenly scheduled scheduled for the Tc-99m MD I-131 for an I-131 whole study by phone.

(20 mci) (10 mci) body scan because 2) The technologist the physician's order administered the was misinterpreted. iodine dose to the

" Total bone scan" was patient without a misinterpreted as written prescrip-fodine-131 total body tion.

scan 6 thyroid scan not specified The technologist None I-131 1-131 misread the physi-(0.050 mci) (3.09 mci) cians's consult order for the thy-roid scan). The licensee's report did not specify what was misread.

7 thyroid uptake not specified Technologist error. None I-131 I-131 The type of error (0.015 mci) (4.9 mC1) (i.e.,misreadingof order, selecting the wrong capsule, etc.)

was not given.

8 thyroid scan thyroid scan Unfamiliar with None (chestscan) (chest scan) dosage requirements, I-131 I-131 the technologist (0.100 mci) (4.9 mci) thought that the higher dosage was required since this type of thyroid scan involved scanning the chest area.

J 9 thyroid scan thyroid scan Unfamiliar with Technologist was (chestscan) (chestscan) dosage requirements, new to nuclear I-131 I-131 the technologist medicine service.

(0.030 mC1) (2.0 mci) thought that the higher dosage was required since this type of thyroid scan involved scanning the chest area.

12 TABLE 4 (Continued)

Primary Cause and Contributing Factors for Each Misadministration Study Radiopharmaceutical Case (dosage)

No. Prescribed Administered Cause Contributing Factors 10 thyroid scan thyroid scan Unfamiliar with Thyroid scan procedure (chest scan) (chestscan) desage requirements, was performed I-131 1-131 the technologist infrequently at the

(.1 mci) (1mC1) thought that the hospital.

higher dosage was required since this type of thyroid scan involved scanning the chest area.

11 thyroid scan I-131 whole The technologist did None Tc-99m body scan not verify the (N/A)* I-131 patient's identity

.(5 mci) and consequently administered the iodine to the wrong patient.

12 thyroid scan thyroid scan The technologist did None I-131 I-131 not assay the iodine-(.2 mC1) (1 mci) 131 dose imediately prior to administer-ing the dose to the patient. The tech-nologist selected the wrong capsule.

13 I-131 whole I-131 whole The nuclear medicine None body scan body scan physician was not I-131 1-131 aware that the left (6 mC1) (6 mci) lobe of the patient's thyroid was intact.

Had this been known, the prescribed dose for the whole body scan would have been 2 mci instead of 6 mCf.

14 thyroid scan not specified The licensee's report None I-131 I-131 did not specify the (0.030 mci) (5.6 mC1) factors that contributed to the misadministration

• Information not available. The normal dosage is 5-10 millicuries.

. 13 Referring to Table 4, we see that for four of the seven misadministrations (1,2,3,5) that involved the misinterpretation /miscommunication of the physician's orders, the physician's order may have contained terminology that led to the orders being misinterpreted /miscommunicated. For example, in each of three cases (1,2,3) either the term " iodine scan" or the term

" iodine thyroid scan and uptake" was used by the referring physician or personnel representing the referring physician to order a thyroid scan.

In the language of the licensees involved, " iodine scan" and " iodine thyroid scan and uptake" apparently meant an " iodine-131 whole body scan,"

a procedure that requires the administration of millicuries amounts of iodine to a patient. Based on our review of literature on the relative use of iodine-131 and other radiopharmaceuticals (iodine-123 and technetium-99m) for performing thyroid scans, the term " iodine scan" is used in some instances to denote that a requested thyroid uptake and scan is to be done with iodine-131 versus iodine-123 or technetium-99m.

Data from a survey on the in vivo use of radioisotopes for the third quarter of 1984 that was published by Medical Marketing, Inc., showed that 47% of thyroid scans are performed using technetium-99m, 40% are performed using iodine-123 and only 13% are performed using fodine-131.

In case 5, the physician's order for a bone scan contained the term

" total body bone scan," this was interpreted by the licensee as an

" iodine-131 whole body scan."

In three (1,2,5) of the four above cases the physician's order for the nuclear medicine study was transmitted to the nuclear medicine service verbally and the technologist administered the iodine dosage without a written prescription.* In a fourth case (4), the prescription for the iodine dosage to be administered to a patient for a thyroid scan was transmitted verbally to the hospital radiopharmacy.

From Table 4, we see for each of the remaining two misadministrations (6,7) involving the misinterpretation /miscommunication of the referring physician's orders, no contributing factors were identified.

2. The Technologist was Not Familiar With The Dosage Requirements for Thyroid Scans. Each of the three misadministrations in this group (8,9,10) involved a technologist administering a higher dosage of iodine to a patient for a thyroid scan than is nonnally prescribed. The type of thyroid scan involved in each case involved scanning the chest area and the technologist apparently thought that a higher dosage of iodine-131 was needed in order to scan the chest area.

Referring to Table 4, we see that for misadministrations cases 9 and 10, the factor identified as contributing to the cause of the misadministration was respectively, the technologist was new to the nuclear medicine service, and thyroid scan procedures were performed infrequently at the hospital where the misadministration occurred.

• In two of these cases (1,5) the licensees had procedures requiring that nuclear medicine studies not be done without a written prescription.

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3. Miscellaneous Causes. Two of the misadministrations in this group (11,12) involved simple errors associated with the identification of patients and the preparation of radiopharmaceuticals: the technologist administered a 10 millicurie dosage of fodine-131 to a patient without verifying that the patient was the patient for whom the dosage was prescribed; and the technologist picked up the wrong iodine capsule and administered it to a patient without verifying the activity of the capsule. These types of errors have been identified in previous AE00 reports on medical misadministrations.

The other misadministration in this group resulted from a unique error:

the nuclear medicine physician or radiologist did not know that part of the patient's thyroid was intact when a 6 millicurie dosage of iodine-131 was prescribed for the patient for a "whole body iodine-131 scan."

From the above analysis, five causal factors associated with the occurrence of the misadministrations can be identified. They are:

use of verbal orders for nuclear medicine studies use of similar terms by referring physicians and licensees to refer to different procedures 1ack of technologist training 1ack of procedures failure of technologist to follow procedures.

These causal factors represent the direct causes of the misadministrations.

However, a review of the general circumstances involved with most of the misadministrations reveals a single underlying cause common to 11 of the 14 misadministrations. That is, licensee personnel did not appear to exercise adequate control over the administration of millicurie amounts of iodine-131 to patients. For example, in these 11 cases the misadministration could likely have been prevented despite the causal factors discussed above if the prescription for the iodine-131 dosage had been verified before the iodine-131 was administered to the patient. In most of the misadministration cases, the technologist administered a dosage of iodine that is normally only prescribed (for diagnostic purposes) for a patient with known thyroid cancer to locate metastatic deposits of the cancer throughout the. body. It appears that a review of the patient's medical history would have revealed that the specific study had erroneously been scheduled for the patient.

A general problem highlighted by the occurrence of these diagnostic mis-administrations involving millicurie amounts of iodine-131 is that licensees may be exercising less control over the administration of millicurie amounts of iodine-131 if the iodine-131 is being adininistered for a diagnostic study (e.g., iodine-131 total body scan) than if the iodine-131 is being administered for a therapeutic purpose (e.g., treatment of hyperthyroidism). For example, a patient to be administered a millicurie or greater dosage of iodine for a therapy procedure, such as for the treatment of hyperthyroidism, is likely to be interviewed by the nuclear medicine physician, radiologist, etc., to ensure the correctness of the dosage, the correctness of the identification of the patient, etc. While there are no regulatory requirements that this be done, the clinical requirements associated with assessing the effectiveness of the therapy will generally require this physician interaction with the patient.

On the other hand, because the technologist uses a dosage schedule to

. 15 determine the radiopharmaceutical and dosage to administer for a prescribed ciagnostic nuclear medicine study (see above), and because diagnostic nuclear medicine studies are more routine procedures (i.e., similar to routine X-ray examinations) than are therapy procedures, a patient may not be interviewed by the nuclear medicine physician, radiologist, etc., before being administered a radiopharmaceutical for a diagnostic study.

Based on the licensee reports, it appears that in each of the 14 misadminis-trations, one to ten millicuries of iodine-131 was administered to a patient without the patient being interviewed by the nuclear medicine physician, radiologist, etc., or otherwise screened to ensure that the dosage of iodine-131 was correct for the patient involved.

This problem seems to be unique to the administration of iodine-131 because the same dosage range of iodine-131 is used for both diagnostic and therapy procedures. The protocols for administering iodine-131 appear to be determined by the purpose (diagnosis or therapy) for which the iodine-131 is administered instead of the amount of iodine-131 administered, an oversight that results from the generally separate protocols that govern the use of radioisotopes for diagnostic and therapeutic purposes.

Licensee Proposed Corrective Action Thirteen of the 14 licensees reporting a misadministration described one or more corrective actions to prevent the recurrence of the misadministrations.

Table 5 summarizes the proposed corrective actions.

TABLE 5 Summary of Licensee Proposed Corrective Actions Number of Licensees

Proposed Corrective Action Recommending Action Require physician (nuclear medicine, radiologist, etc.) 5 to attend the administration of iodine-131 dosages (all dosages or dosages above a specified dosage)

Retrain personnel 6 l

Other 2 None 1 l

From the table, we see that five of the 14 licensees' (35%) proposed corrective I

action would require that the nuclear medicine physician attend the adminis-tration of iodine dosages (either all dosages or dosages above a specified dosage).

l

= - - -

16 F:NDINGS AND CONCLUSIONS The significance of diagnostic misadministrations involving the administration c' mil 11 curie amounts of iodine-131 to a patient is that similar to therapy risadministrations, each misadministration had the potential to result in severe health effects on the patient involved.

The direct causes of ten of the 14 reported fodine misadministrations (71%)

were ascribed to either the physician's order being misinterpreted by or miscomunicated to the technologist (7 cases), or the technologist not knowing the correct dosage to administer for thyroid scan procedures that involved scanning the chest area (3 cases).

Causal factors associated with the occurrences of the misadministrations we re:

use of verbal orders for nuclear medicine studies use of similar terms by referring physicians and licensees to refer to different procedures lack of technologist training lack of procedures failure of technologist to follow procedures.

The underlying cause of 11 of 14 (79%) of the misadministrations appears to have been a lack of licensee control over the administration of millicurie arounts of iodine-131 to patients. These 11 misadministrations could likely have been prevented, despite the errors that led to the misadministrations, if the prescription for the iodine-131 dosage had been verified for each patient before the iodine-131 was administered to the patient.

The precautions that are taken to ensure the accuracy of therapy doses to patients (e.g., interviewing of patients by the nuclear medicine physician, radiologist, etc.), should be taken for the administration of all millicurie amounts of iodine-131, whether the purpose of the administration is diagnostic or therapeutic. However, it appears that licensees may exercise less control over the administration of millicurie amounts of iodine-131 if the iodine-131 is being administered for a diagnostic study (e.g., an iodine-131 total body scan) than if the iodine-131 is being administered for a therapeutic purpose (e.g., treatment of hyperthyroidism).

Based on this engineering evaluation, AE00 suggests that:

(1) The Office of Inspection and Enforcement send an update to Information Notice IN-85-61 (Misadministrations to Patients Undergoing Thyroid Scans) to the affected licensees informing them of the more recent misadministration events involving iodine-131.

(2) NMSS assess the proposed regulatory changes to 10 CFR 35 to determine whether the requirements for quality assurance procedures for radiotherapy facilities should be expanded to include a requirement for quality assurance procedures for the administration of radio-pharmaceuticals for therapy or for diagnosis in which the dosage of the radiopharmaceutical administered is in the therapy dosage range for the radiopharmaceutical.

17 APPENDIX A Descriptions of the Misadministrations MISAD #1 Prescribed Radiopharmaceutical I-123 Prescribed Dosage 0.400 mci Administered Radiopharmaceutical I-131 Administered Dosage 10.0 mci

Description:

The referring physician's secretary telephoned an order for an "icdine scan" to the hospital nuclear medicine department. The nuclear medicine technologist took the tenn " iodine scan" to mean an I-131 whole body scan; the technologist administered a 10 millicurie I-131 capsule to the patient without a written prescription.

MISAD #2 Prescribed Radiopharmaceutical Tc-99m Prescribed Dosage 0.100 mci Administered Radiopharmaceutical I-131 Administered Dosage 5.0 mci

Description:

Personnel in the referring physician's office telephoned an order to the hospital nuclear medicine department for a " radioactive iodine scan". In the licensee's normal terminology radioactive " iodine scan" is a iodine-131 whole body scan. The referring physician intended the order to be for a thyroid scan using iodine-131.

l MISAD #3 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.080 mci Administered Radiopharmaceutical I-131 Administered Dosage 5.6 mci

Description:

i A nursing station submitted an order for an iodine-131 whole body scan to be j performed on a patient. The order should have been for an iodine-131 thyroid uptake and scan. The nursing staff misinterpreted the order from the referring i physician for an " iodine thyroid uptake and scan" for an " iodine-131 whole body scan."

l

. 18 MISAD #4 Prescribed Radiopharmaceutical I-123 Prescribed Dosage 0.15 mC1 Administered Radiopharmaceutical I-131 Administered Dosage 5.0 mci

Description:

The attending physician mistakenly prescribed a dosage of 150 microcuries of iodine-131 instead of iodine-123 for a thyroid uptake study and scan. This order was apparently orally transmitted to the licensee's radiopharmacy where it was interpreted as a request for a 5 millicurie dosage of iodine-131, the iodine-131 dosage normally prescribed for an " iodine-131 whole body scan".

MISAD #5 Prescribed Radiopharmaceutical Tc-99m MDP Prescribed Dosage 20.0 mci Administered Radiopharmaceutical I-131 Administered Dosage 10.0 mci

Description:

The patient was mistakenly scheduled for an iodine-131 "whole body scan". The prescribed study for the patient was "whole body bone scan". The patient was scheduled for the study by telephone. At the time of scheduling, a verbal confirmation for an iodine-131 "whole body scan" was received from the doctor's office. The technologist administered the fodine-131 dose without a written prescription.

MISAD #6 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.050 mci Administered Radiopharmaceutical I-131 Administered Dosage 3.090 mci

Description:

The technologist misread the physician consult (order for the study) and a&ninistered a patient a 3.09 millicurie dosage of fodine-131 instead of a 50 microcurie dosage of iodine-131 for a thyroid scan. The licensee's report did not specify exactly what was misread to cause the technologist to administer the higher dosage of iodine-131.

• 19 MISAD #7 Prescribed Radiopharmaceutical I-131 Pretcribed Dosage 0.015 mci Administered Radiopharmaceutical I-131 Administered Dosage 4.9 mci

Description:

The technologist administered a 4.9 millicurie dosage of iodine-131 instead of a 10 to 15 microcurie dosage of fodine-131 as normally prescribed. The reason for the technologist's error was not given in the licensee's report.

MISAD #8 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.100 mci Administered Radiopharmaceutical I-131 Administered Dosage 4.9 mci

Description:

The chief technologist' ordered a 4.9 millicurie dosage of iodine-131 for a patient undergoing a thyroid scan for diagnosis of substernal extension of an enlarged thyroid (goiter). Since this procedure involves scanning the chest area the technologist thought the higher dosage was required. The technologist apparently related this study to the iodine-131 whole body scan where the chest and other body areas are scanned in searching for " metastatic deposits of functional thyroid carcinomas".

MISAD #9 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.030 mci Administered Radiopharmaceutical I-131 Administered Dosage 2.0 mci

Description:

The technologist administered a 2 millicurie dosage of iodine-131 to a patient for a thyroid scan (chest scan) instead of the 30 microcurie dosage of iodine-131 that was indicated in the physician's notes. The technologist who was new to the nuclear medicine service apparently thought the higher dosage was required because of the need to scan the chest area.

. 20 ,

I l

MISAD #10 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.100 microcurie Administered Radiopharmaceutical I-131 Administered Dosage 1.0 mci

Description:

The technologist administered a 1 millicurie dosage of iodine-131 to a patient for a thyroid scan instead of a dosage of 100 microcuries of iodine-131 which is the dosage normally prescribed at the licensee's facility for thyroid scans.

The patient had a history of possible substernal thyroid (extension of thyroid tissue into the chest area). The technologist appeared to be relatively unfamiliar with the dosage requirements for the thyroid scans which the licensee stated were not performed frequently at the hospital.

MISAD #11 Prescribed Radiopharmaceutical Tc-99m Prescribed Dosage N/A*

Administered Radiopharmaceutical I-131 Administered Dosage 5.00 mci

Description:

The technologist administered a 5 millicurie dosage of iodine-131 to the patient without verifying the patient's identity. The patient was scheduled for a thyroid scan using technetium-99m.

MISAD #12 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.200 microcurie Administered Radiopharmaceutical I-131 Administered Dosage 1.0 mci

Description:

The technologist initially assayed the 200 microcurie capsule but was distracted before administering it to the patient. The technologist then picked up a 1 millicurie capsule, did not assay it, and gave it to the patient.

• Information not available. The normal dosage range is 5-10 millicuries.

, 21 MISAD #13 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 6.0 mci Administered Radiopharmaceutical I-131 Administered Dosage 6.0 mC1

Description:

In prescribing the dosage for an " iodine-131 whole body scan" for a patient the nuclear medicine physician was not aware that one lobe (left) of the patient's thyroid was intact and thus prescribed a dosage of 6 millicuries of iodine-131.

instead of 2 millicuries.

MISAD #14 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.030 mci Administered Radiopharmaceutical I-131 Administered Dosage 5.6 mci Descriptirn:

The cause of the misadministration was not given in the licensee's report.

-. Attachment 2 Summary of Diagnostic Misadministration Reports Received by AE00 Since the Engineering Evaluation was Undertaken MISAD #1 Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.1 - 0.2 mci Administered Radiopharmaceutical I-131 Administered Dosage 1 mci

Description:

A patient was administered a 1 millicurie dosage of iodine-131 instead of the usual 100-200 microcurie dosage of iodine-131 administered for a thyroid scan.

Based on the doctor's office request and the notation in the schedule book,

.the technologist thought the doctor was looking for the residual thyroid tissue and ordered a one millicurie dosage of iodine to be administered to a patient.

i MISAD #2 Prescribed Radiopharmaceutical Tc-99m MDP Prescribed Dosage 20 mci Administered Radiopharmaceutical I-131 Administered Dosage 20 mci

Description:

A patient for whom a bone scan was prescribed was administered 20 millicuries

. of iodine-131 instead of 20 millicuries of techr.etium-99m methylenediphos-phonate as prescribed. The bone scan had been prescribed verbally and was not clearly described on the nuclear medicine department's calendar. The technologist interpreted the ambiguous test description as a request for a

)

thyroid scan.

MISAD #3

. Prescribed Radiopharmaceutical I-131 Prescribed Dosage 0.030-0.050 mci l

Administered Radiopharmaceutical I-131 Administered Dosage 1.53 mci

Description:

A patient was administered a 1.53 millicurie dosage of iodine-131 instead 4 of the prescribed dosage of 30 to 50 microcuries of iodine-131. The thyroid scan was to diagnose possible substernal thyroid tissue and the technologist thought that a whole body scan was ordered to look for metastatic disease.

_ . _ ,