ML18117A064
| ML18117A064 | |
| Person / Time | |
|---|---|
| Issue date: | 04/27/2018 |
| From: | Donna-Beth Howe Office of Nuclear Material Safety and Safeguards |
| To: | |
| Howe D | |
| References | |
| Download: ML18117A064 (15) | |
Text
Medical Events The dose threshold for diagnostic events Status of Medical Events precludes reportable events most years.
FY 2017 Donna-Beth Howe, Ph.D. Each year there are approximately Medical Radiation Safety Team 150,000 therapeutic procedures March 7, 2018 performed utilizing radioactive materials.
1 2 Medical Events 2012-14 Medical Events 2015-17
- 48 Medical events reported - FY 2012
- 57 Medical events reported - FY 2015
- 43 Medical events reported - FY 2013
- 50 Medical events reported - FY 2016
- 46 Medical events reported - FY 2014
- 43 Medical events reported - FY 2017 FY12 FY13 FY 14 FY15 FY16 FY17 35.200 2 0 1 35.200 3 4 0 35.300 2 2 3 35.300 8 4 4 35.400 15 15 5 35.400 9(10) 6(18) 7 35.600 13 10 10 35.600 17 6 8(14) 35.1000 20 16 27 35.1000 20(31) 30 24 3 4 1
Medical Events 2017 35.300 Medical Events (cont.)
35.300 Medical events 4 Iodine-131 3
- Administered 2 mCi when none was prescribed.
Iodine 131 3 - Prescribed parathyroid test but received thyroid Radium 223 1 scan.
- I-131 ordered without written directive.
- Electronic ordering and records system used without confirmation of the order prior to administration.
- Thyroid received 1,630 cGy.
- Modified procedures, confirm dosage orders, and re-trained personnel.
5 6 35.300 Medical Events (cont.) 35.300 Medical Events (cont.)
Iodine-131 cont. Iodine-131 cont.
- Administered 20.2 mCi instead of 30 mCi in written
- Administered 106 mCi instead of 150 mCi.
directive. - Dosage delivered in two capsules.
- Written Directive was incorrect. - Patient shook the vial contents into her mouth, only
- Intended dose was given. swallowed one capsule, other left in vial.
- Three individuals now review the Written Directive - Discovered when capsule returned to the pharmacy.
for accuracy before signing and administration.
7 8 2
35.300 Medical Events (cont.) Medical Events 2017 Ra-223 dichloride 1 35.400 Medical events 7
- Administered 176.1 µCi instead of 108.4 µCi.
- Wrong patient.
- Two patients scheduled for Ra-223 treatment on the Prostate 7 same day. One licensee 2 reports 2
- Doses properly labeled with patient names on the lead Human error pigs and syringes.
Anatomy
- Wrong syringe used without checking patient identity.
Wrong site 1
- Added a timeout, dosing physician verifies identity of Used previous activity 1 the patient and prescribed dose in the written directive.
Larger then pre plan or swelling 3 9 10 35.400 Medical Events 35.400 Medical Events Prostate 7
- Case 2 - Patient received 78% of the prescribed D90 dose of 14,500 cGy.
- One licensee, 2 separate reports
- Caused by patient anatomy.
- Case 1 - Patient received 62% of the prescribed D90
- Identified during post-implant CT scan and dose of 14,500cGy.
subsequent dosimetric analysis.
- No root cause but attributed to human error. - Delay in reporting to State due to communication
- Some seeds may have migrated post implant. breakdown and inadequate procedures.
11 12 3
35.400 Medical Events cont. 35.400 Medical Events cont.
- Patient received 2,760 cGy instead of 11,000 cGy
- Patient received 157.81% of the prescribed D90 74.9% less than prescribed. dose of 12,500 cGy - Pd-103 seeds.
- Wrong site. - Failed to enter correct activity per seed into physics
- Estimated dose to the urethra at 2,602 cGy (rad), the spreadsheet that contained a value from the previous rectum at 861 cGy, and the penile bulb at 8,689 cGy. calculation.
- human error - additional training to personnel and - Did not perform independent verification of treatment improved supervision. data.
- New action: secondary hand calculation, require use of blank spreadsheet template, and verbal time-out to verify key parameters prior to treatment.
13 14 35.400 Medical Events cont. 35.400 Medical Events cont.
- Prescribed 14,400 cGy received 73% of the dose.
- Prescribed 14,500 cGy received 10,000 cGy - 69% of
- 18% increase in prostate size compared to the pre- the dose.
plan and the planned intentional cooler coverage - Administered 12/7/2016, event discovered on near the patient's rectum. 12/8/2016.
- Discovered during a routine audit conducted by a - Second treatment on 12/9/2016 - eight more seeds medical physicist. implanted.
- Post-operative swelling and seed migration
- Perform post-implant imaging sooner to minimize the effect of swelling of the prostate gland and possible migration of the seed 15 16 4
35.400 Medical Events cont. Medical Events 2017
- Prescribed 14,500 cGy received 10,353 cGy - 71% of 35.600 Medical events 8(15) the dose. HDR
- Order additional seeds beyond what the pre-plan
- Gynecological(14) 7 requires. Software Issue (9 patients) 2
- Perform post-implant x-ray and ultrasound to Wrong site 4 determine if/where additional seeds could be placed.
Equipment failure 1 Gamma Knife 1 17 18 35.600 HDR Events (cont.) 35.600 HDR Gynecological (cont.)
Gynecological 7 (14)
- Generic Software issue cont. (5 patients)
- Oncentra software versions 4.5.2 issue with source
- Generic Software issue (4 patients) step size with ring of 5 mm instead of 2.5 mm.
- Oncentra software versions 4.5, 4.5.1, and 4.5.2 issue
- Dose to treatment site 24.46%, 21%, 31.96%,
with source step size with ring.
25.58%and 20.89% less than intended.
- Source step size of 5 mm instead of 2.5 mm.
- Did not calculate dose to the unintended site.
- Dose to unintended site 2,800 cGy to 1,400 cGy.
- Some source paths extended beyond planned endpoint
- Dose to the unintended site expected too be 126 to and started on a return path back into the lower vagina.
175 cGy per fraction.
- Some tissue protection by fluid-filled sleeve that
- Elekta notified software users of problem with ring. provided some shielding and displacement.
19 20 5
35.600 HDR Gynecological (cont.) 35.600 HDR Gynecological (cont.)
- Wrong site 4
- Wrong Site cont.
- 5 cm site received 500 cGy - Capri applicator inserted into the patient's rectum
- Wrong software orientation selected. instead of vagina on 2nd of 5 fractions.
- Oncentra treatment planning - must choose if the - Treatment site received prescribed dose of 350 cGy treatment catheters are modeled from the tip or (rad) during the second treatment.
connecting end of the catheter. - Radiologist confirmed the patient's rectum had been
- Catheter in the tip end mode which was incorrect. treated.
- Provide additional training to personnel.
21 22 35.600 HDR Gynecological (cont.) 35.600 HDR Gynecological (cont.)
- Wrong site cont.
- Wrong site cont.
- 5 cm site received 500 cGy - Received 700 cGy
- first two tandem and ovoid treatments were - Physicist determined inserted length of the transfer guide tube was 7.5 cm shorter than intended.
delivered as prescribed
- The transfer tube was deformed and added pressure
- Incorrect tandem applicator length of 119.8 cm needed to fully insert it into the applicator.
was entered into the treatment planning system - Removed the transfer guide tube from service, got for third fraction instead of the prescribed 131.9 different design.
cm. - Counseled staff on the event.
23 24 6
35.600 HDR Gynecological (cont.) 35.600 Gamma knife 1
- Equipment failure. Gamma Knife Model C.
- Received 6.4% of prescribed 500 cGy dose during the 1st of 5 fractions.
- Prescribed 2000 cGy received 1540 cGy to brain lesion
- Five separate interlocks were tripped in 1st fraction.
- Three of five shots delivered.
- fluid in the catheter may have contaminated the source and afterloader unit. - Couch retracted from the treatment position due to a clutch malfunction.
- Patient was released - repairs completed in six hours.
- Patient elected to not return.
25 26 Medical Events 2017 35.1000 Medical Events Intravascular Brachytherapy 1 35.1000 Medical events 24
- Prescribed dose of 1,840 cGy (rad) for in-stent Intervascular Brachytherapy 1 restenosis in two dwell positions.
- Received 50% of dose - one position treated.
Y-90 Microspheres 23 - Source train stuck - not retract to the afterloader.
- Deformation 7.3 cm distal to the strain relief - located Therasphere 15 outside the patient.
SirSphere 8 - Compression of the catheter during a challenging advancement into a commonly tortuous vessel (left internal mammary artery).
27 28 7
35.1000 Medical Events 35.1000 Therasphere Y-90 Events Y-90 Microspheres 23 Overdose 3 Therasphere 15
- Prescribed 11,000 cGy administered 54,000 cGy -
- Over dose 3 right lobe
- Wrong site 2
- Wrong calibration date (6/11/2017 instead of
- Kinked catheter 4 6/4/2017) used in ordering.
- Cracked catheter 1 - Used dose calibrator - did not question results.
- Partial Obstruction 1 - Written directive not prepared and not signed before
- Leaking connection 2 administration.
- Slow infusion 1 - Shunting lung dose 2,576 cGy (rad), - intended 524
- Reflux to other lobe 1 cGy (rad).
- About 6 months later no clinically significant symptomatic complications.
29 30 35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
- Prescribed 34,000 cGy administered 80,800 cGy -
- Prescribed 34,000 cGy administered 80,800 cGy -
liver volume. liver volume. (cont.)
- Administered before microspheres decayed to the - Spreadsheet to calculate patient dose modified to prescribed activity - Scheduling nurse used the pre- check the administration vial's calibration activity and treatment plan instead of the final treatment plan. date versus the prescribed activity and procedure
- The physicists pre-treatment calculations and time- date.
out failed. - The time-out procedure modified to confirm the proper activity prior to administration.
31 32 8
35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Wrong site 3 Overdose cont.
- Prescribed 6,000 cGy - administered 4,860 cGy (rad)
- Prescribed activity 1.05 GBq (28.37 mCi) - to the left lobe and 3,650 cGy (rad) to the right lobe.
administered activity was 2.05 GBq (55.35 mCi).
- Challenging anatomy - a narrow window just distal to
- Human error in converting activity from GBq to mCi. vasculature suppling right lobe - reflux to right lobe.
- Corrective actions - procedure modifications, written - Verified catheter position multiple ways before directive revisions, and software updates to assist in administration - no apparent complications.
unit conversions.
- Bremsstrahlung imaging showed microspheres in both lobes.
33 34 35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Wrong site Wrong site cont.
- Prescribed 6,000 cGy - administered 4,860 cGy (rad)
- Two separate segments in the right lobe - prescribed to the left lobe and 3,650 cGy (rad) to the right lobe. 25.6 mCi to the small segment and 64.3 mCi to the (cont.) large segment.
- Movement of the catheter from unnoticed patient - Later discovered only 10.27 mCi was ordered for the movement (breathing) or angiographically undetected large segment.
reflux caused by the difference in flow dynamics of - Each dose needed different calibration dates.
the microspheres, contrast agent and Tc-99M macro- - Contrary to vendor guidance, the licensee used one aggregated albumin (MAA). order sheet for the two doses with one calibration date 35 36 9
35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Wrong site cont. Wrong site cont.
- Two separate segments in the right lobe prescribed
- Prescribed 47.03 mCi to the left lobe - administered 25.6 mCi to the small segment and 64.3 mCi to the 46.22 mCi to right lobe (right lobe to be treated one large segment. (cont.) month later).
- Process involved several hand-offs, reviews, and - Interventional radiologist and radiation oncologist verifications by different providers using different authorized user signed off on the planned activity for source documents - inconsistency between the written the left lobe via the left hepatic artery - the authorized directive and the order and assay data was not user completed the written directive.
identified prior to patient treatment. - Interventional radiologist put catheter in patient's right hepatic artery for right lobe - human error confused about later treatment of right.
37 38 35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Wrong site cont. Kinking 4
- Prescribed 47.03 mCi to the left lobe - administered
- Prescribed 146.51 mCi - administered 11.35 mCi -
46.22 mCi to right lobe (right lobe to be treated one liver dose of 970 cGy (rad) and lung dose from month later). (cont.) shunting of 101 cGy (rad).
- In operating room time-out all parties confirmed the - Thought slow injection flowrate, dent in the outlet procedure, and treatment was administered. tubing from a pinch-clamp, and over-tightening of the
- Modified written directive time out procedure. Touhy-Borst Y-adaptor caused sedimentation of the microspheres in the delivery system.
- The manufacturer's inspection a small mass of microspheres inside the dose vial and within the outlet tubing, multiple locations with kinks, no septum fragments or other obstructions were observed, no evidence that the Tuohy fitting was over tightened.
39 40 10
35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Kinking cont. Kinking cont.
- Prescribed 12,000 rad - administered 6,000 rad.
- Prescribed 46 mCi administered 20 mCi.
- A kinked delivery catheter prohibited complete - Two separate liver segments.
microsphere administration. - Second acrylic jar contained 56% of the microspheres
- Prescribed 51.57 - administered 39.07 mCi to the intended for the patient's second liver segment.
right lobe. - Protocols for dose preparation, box construction, and
- Residual activity 12.5 mCi remaining in the delivery dose administration were followed.
device. - Minor resistance during the flush of the stretched out
- Visual kink at the hub of the catheter was identified. micro-catheter.
- Possible micro-catheter had a kink and be able to flush contrast and saline through it, but have microspheres clog it.
41 42 35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Cracked catheter 1 Partial obstruction 1
- Prescribed two doses with a total activity of 54 mCi
- Prescribed 47.88 mCi - administered 13.91mCi.
to the right and left lobes - administered 21.62 mCi - Thought treatment went as planned, no issues with
- first dose and second administrations through the viewed flow before administration, no increased radial artery of the left hand using a microcatheter resistance was noted and could flush the line post (Marksman). administration.
- Post radiation surveys both about 5 mR/hr for the - Discovered during survey of waste and performing microsphere vial - AU assumed first was from the dose assessment.
contaminated cloth but recognized second meant two under doses.
- Visual inspection of the microcatheter revealed a crack - the crack was determined to be the cause of the event.
43 44 11
35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Partial obstruction 1 Leaking catheter connection 2
- Prescribed 47.88 mCi - administered 13.91mCi.
- Prescribed 11.87 mCi - administered 8.34 mCi.
(cont.) - During treatment liquid leaking from the connection
- Thought partial obstruction in catheter or line between the e-line and the catheter placed in the connecting the microsphere vial to the catheter, patient was noted.
vasculature was complicated and may have resulted - Treatment stopped and started decontamination -
in movement of the micro-catheter slightly forward patient's thigh and groin, skin dose was calculated to from initial placement. be 1.1 µSv (0.11 mrem).
- Greater than usual amount of saline in the overflow - Incident due to human error - poor connection vial. between the e-line and the patient's catheter.
45 46 35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Therasphere (cont.)
Leaking catheter connection cont. Slow injection rate 1
- Prescribed 25.95 mCi - administered 8.99 mCi.
- prescribed 175.7 mCi - administered 43.24 mCi.
- Leak occurred while connecting the infusion line from - Slow injection rate to prevent reflux into adjacent the microsphere vial to the microcatheter. gastric artery that could not be coil embolized.
- Physician simultaneously unclamped the - Completed administration, three saline flushes, administration line while trying to connect it to the verified digital radiation dosimeter was reading 0.0, microcatheter. indicating that the microspheres had left the vial.
- Physician assumed the leaking fluid only contained - Microspheres collected in the catheter outside of the saline and proceeded with administration. patient.
- Leak caused contamination of the administration area, which was immediately decontaminated.
47 48 12
35.1000 Y-90 Therasphere (cont.) 35.1000 Y-90 Events (cont.)
Slow injection rate 1 SirSphere 8
- prescribed 175.7 mCi - administered 43.24 mCi. - Labeled vial shield not vial 1 (cont.) - Low activity administration 3
- External experts confirmed that a slow injection rate - High activity clogging 1 can result in an event like this and RSO identified - Clogging issues 3 catheter backup in another slow injection rate administration.
- Needle 1
- Catheter defect 1
Labeled vial shield not vial 1 Low activity administration 3
- Prescribed 2.453 mCi to small lesion and 22.077
- Prescribed 6.49 mCi to 2 segments - administered mCi to large lesion - administered 22.077 mCi to 4.46 mCi.
small lesion. - Activity in residual waste - stasis was not reached
- Prepared two vials, labeled each vial shield, did not during administration.
label the vials. - Procedure modifications, form modifications, written
- Provided vial with 22.077 mCi for small lesion directive adjusted to tighten up the dose drawn to realized mistake when started large lesion. match 100% of the prescribed dose, and committed
- Require time-out, label both the vial and vial shield, to have an AMP physician present to observe low read labels three times before administration. activity administrations.
51 52 13
35.1000 Y-90 SirSphere (cont.) 35.1000 Y-90 SirSphere (cont.)
Low activity administration cont, Low activity administration cont,
- Prescribed 5.49 mCi - administered 4.07 mCi.
- Prescribed 4.05 mCi - administered 3.14 mCi.
- Cause of the event was the amount of activity - Radiation survey revealed residual activity of 1.06 delivered; the relatively low prescribed dose made mCi remained in the treatment device.
the residue look comparatively large. - The use of small doses will be carried out after
- Another doctor will supervise the remainder of the greater scrutiny and review.
administrating doctors cases - part of the requirements for obtaining authorized user status.
53 54 35.1000 Y-90 SirSphere (cont.) 35.1000 Y-90 SirSphere (cont.)
High activity clogging 1 Clogged needle 1
- Prescribed 84.12 mCi - administered 59.8 mCi.
- Prescribed 32.97 mCi - administered 8.2 mCi.
- Tubing became clogged and the entire activity could - Occlusion of the vial delivery C needle due to not be administered. clumping of the microspheres.
- Due to a large dose of microspheres - increased - Intended to return to manufacturer but discarded after amount of microspheres in the system clogged the activity decayed to background.
micro-catheter towards the patient. - Educating the administrator of the microspheres on how to clear the clogged needle, which is to reverse the valve for flushing purposes.
55 56 14
35.1000 Y-90 SirSphere (cont.) 35.1000 Y-90 SirSphere (cont.)
Catheter defect 1 Kinked catheter 1
- Prescribed 12.16 mCi - administered 5.64 mCi.
- Prescribed 40.4 mCi - administered 21.5 mCi.
- AU and interventional radiologist noticed a strong - Think patient inhaled deeply and created a kink in the resistance as they pushed on the syringe. catheter.
- The micro-catheter was pulled from the patient - a - The first three or four aliquots were delivered before very small defect was observed. the plunger met resistance.
- Cause of the microsphere blockage was a defect in - Kinked catheter was confirmed by PET/CT imaging of the micro-catheter. the administration set and vial.
- MedWatch FDA Adverse Event form completed.
57 58 Acronyms
- AU - Authorized User
- cGy - centiGray
- FY - Fiscal Year
- GBq - Giga Becquerel QUESTIONS?
- HDR - High Dose Rate Remote Afterloader
- I-124 - Iodine-124
- Ra-223 -Radium-223
- mCi - millicurie
- µCi - microcurie
- MBq - Mega Becquerel 59 60 15