ML19116A137
| ML19116A137 | |
| Person / Time | |
|---|---|
| Issue date: | 04/03/2019 |
| From: | Donna-Beth Howe NRC/NMSS/DMSST/MSEB |
| To: | |
| Howe, Donna-Beth | |
| References | |
| Download: ML19116A137 (17) | |
Text
Medical Events The dose threshold for diagnostic events Status of Medical Events precludes reportable events most years.
FY 2018 Each year, there are approximately 150,000 therapeutic procedures performed utilizing Donna-Beth Howe, Ph.D. radioactive materials.
Medical Radiation Safety Team April 3, 2019 1 2 Medical Events FY 2013 - 2015 Medical Events FY 2016 - 2018
- 43 Medical events reported - FY 2013
- 50 Medical events reported - FY 2016
- 46 Medical events reported - FY 2014
- 43 Medical events reported - FY 2016
- 57 Medical events reported - FY 2015
- 48 Medical events reported - FY 2018 FY13 FY14 FY15 35.200 0 1 3 FY16 FY17 FY18 35.300 2 3 8 35.200 4 0 0 35.400 15 5 9 (10*) 35.300 4 4 2 35.600 10 10 17 35.400 6 (18) 7 11 (13) 35.1000 16 27 20 (30) 35.600 6 8 (14) 10
- The total number of patients involved if greater than 35.1000 30 24 25 (26) the number of reports 3 4 1
Medical Events 2018 35.300 Medical Events 35.300 Medical events 2 Iodine-131 MIBG 1
- 50,000 to 12,000 cGy skin dose to 15 cm² Iodine-131 MIBG 1 - Patient was disconnected from infusion pump at Spiros connection to use restroom.
- At end of procedure, high activity of I-131 on patients clothing and bed linen.
- Two days later, patient reported discomfort and reddening of skin on upper right thigh erythematous lesion to desquamation the next day.
5 6*
35.300 Medical Events 35.300 Medical Events Iodine-131 MIBG (cont.) Ra-223 dichloride 1
- 50,000 to 120,000 cGy skin dose to 15 cm²
- Administered 176.1 µCi instead of 180 µCi
- Did not decontaminate patient until signs of - Signed written directive called for oral administration erythema.
- Technologist administered intravenous
- Will only disconnect patient if medical emergency.
- Will implement new written directive
- Will use adsorbent pads under administration line.
- Review current policy and procedures with staff
- Will develop patient specific decontamination procedures.
7 8 2
Medical Events 2018 35.400 Medical Events 35.400 Medical events 13 (15) Eye Plaque 1
- Prescribed 8,600 cGy - received 6,500 cGy Eye Plaque 1 Unknown procedure 1 - Used new model of eye plaque that differed from old Prostate 9 (11) model
- Isodose curves differed from brachytherapy plan.
One licensee, 3 reports 3 (5)
- Dose was deeper than expected Human error 2 Wrong site 1 Larger than pre-plan or swelling 2 9 10 35.400 Medical Events 35.400 Medical Events Prostate 9 (11)
Unknown Procedure 1 One licensee, 3 separate reports, 5 patients
- Report 1 - First patient prescribed 14,000 cGy, but
- 70% of the intended dose was delivered administered 8,990 cGy - 62% of prescribed dose
- No root cause, but attributed to human error
- Some seeds may have migrated post-implant
- Performed historical review after inspection
- Second Patient prescribed 14,500 cGy, but received 19,200 cGy - 132% of the prescribed dose
- Third Patient prescribed 14,500 cGy, but received 18,900 cGy - 130% of the prescribed dose 11 12 3
35.400 Medical Events 35.400 Medical Events One licensee, 3 separate reports, 5 patients (cont.)
- Patient prescribed 11,000 cGy, but received 5,815 cGy - 53% of dose
- Report 2 - Patient prescribed 14,500 cGy, but received - Partial seed strand implanted in the bladder 10,500 cGy - 72.4% of the prescribed dose - Removed errant seeds immediately with cystoscopy
- Attributed to human error
- Report 3 - Patient prescribed 14,500 cGy, but received - Corrective actions include:
7,000 cGy - 48% of the prescribed dose
- New written procedure
- Use of more needles, more seeds, and less aggressive sparing of the urethra
- Stop using pre-loaded stranded seeds, so improperly implanted seeds can be individually 13 14 35.400 Medical Events 35.400 Medical Events
- Patient intended 10,800 cGy, but 50% of prostate
- Patient prescribed 11,000 cGy, but received 6,215 received no dose cGy - 56.5% of dose
- Ultrasound volume of prostate was smaller on - Attributed to human error ultrasound pre-implant scan than CT post-implant - Improve imaging techniques scan
- Real-time implantation with ultrasound did not permit
- Patient prescribed 14,400 cGy, but received only potential visualization errors 73% of dose
- Attributed to human error
- Attributed to 18% increase in prostate size compared
- Corrective actions include: to pre-plan
- Additional training to personnel and improved supervision
- Planned intentional cooler coverage near rectum
- Terminate the seed implant program due to low patient volume - Additional training to personnel 15 16 4
35.400 Medical Events 35.400 Medical Events
- Patient intended 12,500 cGy, but received 1,000 cGy
- Patient intended 12,500 cGy, but received 1,000 12.5% of dose (Pd-103 seeds) cGy 12.5% of dose (Pd-103 seeds) [cont.]
- Used Foley catheter but inflated balloon in prostate - Physician and medical physicist will audibly concur urethra instead of bladder on image quality before preceding
- 32 of 54 seeds placed outside prostate and 3 seeds - Manufacturer reset new default magnification value could not be seen that will initial view of relevant prostate anatomy
- Expect risk of radiation damage to rectum and - Once first seed is implanted, fluoroscopic image will surrounding tissue be used to verify relative location of seed and Foley
- Failed to locate Foley catheter compounded by using catheter is where it is expected to be magnification factor of ultrasound device that did not give full view of relevant anatomy 17* 18 35.400 Medical Events Medical Events 2018
- Patient prescribed 12,500 cGy, but received 9,670 35.600 Medical events 10 cGy - 77% of dose (Pd-103 seeds)
- Three seeds from one needle did not remain in place HDR
- Contributing factors:
- Skin 1
- AUs preference for peripheral loading
- Potential rotation of the prostate during needle insertion
- Breast 2
- Pressure effects from using hydrogel to separate prostate
- Gynecological 7 from rectum Device malfunction 2
- Corrective actions: Wrong site 3
- No longer implant needle between urethra and rectum - will use two needles offset on axis Human mistake 2
- Use stabilized needles during surgery 19 20 5
35.600 HDR Events 35.600 HDR Events Skin 1 Skin (cont.)
- Lack of policy for custom immobilization devices for
- Patient prescribed 8 fractions of 500 cGy skin treatment each to temple area, but received 350 cGy - Therapist present at first treatment and any time there on first 2 fractions is a new physicist
- First physicist used incorrect setup - forgot to use - Photograph set up with and without patient to show accuform - second physicist used correct setup accuform
- Wrong position - gap between treatment device and - Barcode scanning to track custom set up devices patients skin 21 22*
35.600 HDR Events 35.600 HDR Events Breast 2 Breast 2
- Wrong site - 1,200 cGy to lateral breast skin
- Wrong site - 1 cc volume of skin received 850
- Patient contacted oncologist because of skin reaction cGy instead of intended 256 cGy
- Physicist used tip end instead of connector end in - Savi applicator - struts 2 and 6 mislabeled - changed treatment plan orientation of the applicator - direction of radiation
- Corrective actions: - Corrective actions:
- Additional training to personnel
- Second physicist to independently verify catheter struts in treatment plan.
- HDR review checklist - verify digitization of struts in treatment plan
- Add HDR plan review to monthly audit
- Additional training to personnel 23 24 6
35.600 HDR Events 35.600 HDR Events Gynecological 7
- Device malfunction
- Device malfunction - Device failed to fully retract at completion of treatment
- Patient to receive 1,500 cGy during 3 fractions in 13 fraction dwell points - Dose of 100 cGY to patient thigh - source was 5 cm
- HDR unit malfunctioned at dwell point 9 from cylinder guide tube connector
- Treatment adjusted after repair of the HDR unit - Source wire was bent near source
- Delay in removing source from vicinity of patient and reporting the event to RSO 25 26 35.600 HDR Events 35.600 HDR Events
- Catheter movement - connector locking nut too
- Prescribed 6 fractions of 350 cGy each - first loose, which allowed catheter to slide out fraction received 2,100 cGy
- Event discovered by skin reaction progressed to moist - Total treatment time incorrectly entered into treatment desquamation planning system
- Dose to skin of 5,154 to 8,555 cGy - Human error and poor decision making - started first
- Corrective action: treatment after hours - second physicist not available
- Retrain medical staff and AU - Corrective actions:
- AU will double check all connections and placement before and
- Second physicist has to independently verify treatment plan after each treatment
- Physicist to check that plan was exported correctly to the
- Purchased new cylinder with new design treatment console 27 28 7
35.600 HDR Events 35.600 HDR Events
- Wrong Site - 587 cGy dose to small
- Wrong site - 5.5 cm outside the treatment site intestine and bowel instead of 220 cGy received 500 cGy in 0.5 cm volume
- Patients pelvis had extensive damage from uterine - Channel 12 digitized twice with no digitization of cancer Channel 13 (Channel 13 digitization included in Channel 12 with no dwell positions for 13)
- Two dwell positions shifted to deliver dose to non-targeted small intestine/bowel in first of 3 fractions - Treatment plan displayed expected dose distribution to critical organs and tumor and no dwell positions for
- Treatment plan modified for next 2 fractions Channel 13
- Licensee thought not reportable - 10 CFR 35.3045(a)(1)
- Physician approved the plan and (3); NRC determined reportable - 10 CFR 35.3045(a)(1)(iii) and (a)(3) 29 30*
35.600 HDR Events 35.600 HDR Events
- Wrong site - 5.5 cm outside the treatment site
- Wrong site - 100 cGy outside treatment site received 500 cGy in 0.5 cm volume (cont.) Prescribed 1,890 cGy, but received 1,675 cGy
- Patient discomfort (full bladder) - In first of three fractions digitize the catheter as linear
- Physicist rushed to complete the plan and export to instead of as a single curved catheter treatment console - error overlooked - Physicist failed to recognize the incorrectly
- Corrective action: reconstructed catheter shape in planning software
- Second check by physicist that did not prepare the plan - Treatment length of 15.7 cm instead of 9 cm
- Each channel will be carefully reviewed
- Patient not brought to treatment area until plan has been checked and exported to console 31 32*
8
35.600 HDR Events (cont.) Medical Events 2018
- Wrong site - 100 cGy outside treatment site 35.1000 Medical events 25 (cont.)
- Discovered on second fraction Perfexion 1
- Treatment plan was not enlarged so physicist could not Intervascular Brachytherapy 1 see the dwell points overlapping Radioactive seed localization 1
- Corrective actions:
- Enlarge each treatment plan in which the physicist signs off Y-90 Microspheres 22
- Use of a formalized check list Unidentified 2 Therasphere 13 SirSphere 7 33 34 35.1000 Medical Events 35.1000 Medical Events Perfexion 1 Intravascular Brachytherapy 1
- Device malfunctioned - First extra long delivery catheter - source could not get to treatment site and retracted safely to unit
- Device recorded an error and backup power was low, - Second extra long treatment catheter - source still so the sources were returned to the shielded position could not get to treatment site but source could not
- One-third of prescribed dose delivered be returned to IVB unit; all catheters removed
- Hydraulic return mechanism failed to return source.
- No dose to treatment site and 39 cGy to surrounding tissue
- Deformation of delivery catheter confirmed root cause 35 36 9
35.1000 Medical Events 35.1000 Medical Events Radioactive seed localization 1 Y-90 Microspheres 25
- Expected dose 12 cGy to tissue, but patient received 99 cGy to tissue Unknown 2
- Seed implanted and scheduled for removal 6 days later
- Insurance company rescinded approval after seed was implanted and required 3 medical opinions
- Surgery performed approximately 64 days after implant 37 38 35.1000 Unknown Y-90 Events 35.1000 Medical Events Unknown 2 Y-90 Microspheres 25
- Prescribed 13,400 cGy to a segment of the liver, but Therasphere 13 (14) received 10,300 cGy - 77% of intended dose - Overdose 1
- Catheter/Obstruction 8
- Patient received 60% of prescribed dose - Bubbles 2
- Backflow to contrast 1
- Human mistake 1 39 40 10
35.1000 Y-90 Therasphere Events 35.1000 Y-90 Therasphere Events Overdose Dose in Waste Jar
- Prescribed 13,600 cGy, but received 29,400 cGy
- Prescribed 12,000 cGy administered 1,770 cGy -
- Picked up wrong dosage, measured and compared liver volume - 14% of intended dose activity to shipping box information and not the - Licensee thought equipment did not function as written directive designed
- Shipping box was for next weeks patient - Most of the dosage was in the waste jar
- Post administration calculations identified the - Manufacturer could not determine root cause medical event
- Will add a dose verification step in interventional radiology 41 42 35.1000 Y-90 Therasphere Events 35.1000 Y-90 Therasphere Events
- Two patients received less dose than prescribed
- Prescribed activity 122 mCi - received 46 mCi - 38%
- First patient prescribed 72.6 mCi, but received 15 of intended activity mCi. Inspector thought expansion tubing resulted in - From device components sent to manufacturer no turbulent flow triggering suspension issues cause for the blockage was determined
- Second patient prescribed 72 mCi, but received 36.75 - Obstruction/blockage located in microcatheter -
mCi - Inspector thought lack of adequate agitation obstruction in the outlet tubing at the E junction prior to administration or issues with quality/sizing of - Manufacturer recommended handling microcatheters microspheres with extra care and looking for kinks
- Extension tubing no longer used
- Manufacturer supported Inspectors findings 43 44 11
35.1000 Y-90 Therasphere Events 35.1000 Y-90 Therasphere Events
- Prescribed 12,000 cGy - received 2,000 cGy (rad) One licensee - 2 reported medical events
- Malfunction in the administrative set - significantly
- Report 1 - Prescribed 64.8 mCi, but received 41 less pressure than usual to press syringe mCi - 65% of activity
- Saline accumulating in overflow vial
- Air bubbles noted in overflow tubing connected to the
- Only returned portion of administration set that infused micro-catheter dosage into patient to manufacturer
- Connected 3-way stopcock between overflow tubing
- May have been a kink or obstruction in treatment and micro-catheter aspirated bubbles to syringe with catheter but not conclusive stopcock close to patient
- Will send complete administrative set next time - Resurvey of delivery kit showed residual activity 45 46*
35.1000 Y-90 Therasphere Events 35.1000 Y-90 Therasphere Events
- Prescribed 89,200 cGy, but received 57,500 cGy -
- Report 2 - Prescribed 46 mCi but received 27 mCi - 64% of dose 59% of activity - Backflow of microspheres into contrast line and
- Used left radial artery with 5-French Sarah Radial syringe catheter with coaxial micro-catheter - Significant contamination in contrast syringe, flushing
- Nothing unusual was encountered syringe, contrast tubing, and associated y-adaptor
- No radioactive contamination of the suite - Thought contrasting syringe and tubing were made of
- Dose was in catheter, gauze, dose vial and other materials that bind microspheres more than waste administration kit - will look for same materials
- Will use clamp and one-way valve 47 48 12
35.1000 Y-90 Therasphere Events 35.1000 Y-90 Therasphere Events
- Prescribed 23 mCi, but received 7.4 mCi - 32% of the
- Prescribed 35 mCi, but received 5.4 mCi - 16% of activity activity
- Blockage occurred in the delivery apparatus - Microspheres were coagulated in the tubing
- Imaged the administration set and saw most of the - Unexpected activity remained near the Touhy-Borst undelivered activity near where plunger connects to connector the dose vial - Manufacturer thought caused by issues with the
- Will send administration set and procedure waste to micro-catheter contractor for manufacturer - Will flush micro-catheter immediately prior to connecting it to the administration kit 49 50 35.1000 Y-90 Therasphere Events 35.1000 Y-90 Therasphere Events
- Prescribed 13,000 cGy to left lobe of liver, but
- Prescribed 24,500 cGy, but administered 13,083 cGy received 8,490 cGy - 65% of dose - 53% of dose
- First vial administered without incident - CT scan verified dose was administered to correct
- Second vial primed and prepped, but saw a train of location bubbles in the line between the dose vial and patient - Remainder of dose hung up in catheter despite
- AU stopped the procedure; did not want the bubbles flushing to cause the flow to reflux into gastric artery and - Catheter tubing met manufacturers specifications cause permanent damage to the stomach - No root cause identified
- Could not pinpoint cause of bubbles
- Limit number of staff trained to prime and do set-up and ensure enough are available on treatment days 51 52 13
35.1000 Y-90 Therasphere Events 35.1000 Medical Events
- Prescribed 1,300 cGy to specific part of liver, but SirSphere 7 received 931 cGy - 71% of dose
- Used 3 different written directives to fractionate the - Wrong site 2 delivery - Measurement unit error 1
- Thought the small activity prescribed contributed to - Written Directive error 1 under dose because of typical losses in the valve and
- High activity clogging 1 tubing
- Low activity administration 1
- Order higher dosages for any administration below 10 mCi
- Amend license to go to different manufacturer 53 54 35.1000 Y-90 SirSphere Events 35.1000 Y-90 SirSphere Events Wrong treatment site 2 Wrong treatment site (cont.)
- Prescribed 38.4 mCi to liver but received about 13 - Difficult visualizing arterial access to the tumor mCi to abdominal wall - Micro-catheter was not advanced far enough into
- Post-treatment scan appeared normal with small correct artery uptake in bowel - Pre-existing kidney impairment precluded using more
- Pain in abdomen with erythema on abdomen - contrast thought dose was above 55 cGy but less than 1,000 - Add second monitor to refer to original arteriogram cGy without switching tasks and improve confidence of
- Thought one-third of dose migrated up a venous correct location ligament and lodged in abdominal wall - Take prophylactic measures for future patients with impaired kidney function 55* 56 14
35.1000 Y-90 SirSphere Events 35.1000 Y-90 SirSphere Events Wrong site Measurement Unit Error
- Prescribed 4,874 cGy to right lobe of liver, but
- Prescribed 0.91 GBq, but received 8.9 mCi received 11,080 cGy to left lobe
- Ordered 0.91 mCi - marked wrong box in computer
- Did not multiply measured dose value by correction
- Human error factor of 10
- Placed catheter in left hepatic artery instead of right - Not identify until post-procedure check hepatic artery
- Worksheet revised to be in SI units
- Written directive sheet to be in SI units
- Dose preparation and post-procedure forms to be in SI units 57 58 35.1000 Y-90 SirSphere Events 35.1000 Y-90 SirSphere Events Written Directive Error High activity clogging 1
- Prescribed 1,504 cGy to right lobe of liver, but
- Prescribed 4,320 cGy, but received 828 cGy - 19%
received 1,498 cGy in left lobe of the dose
- Written directive prepared incorrectly - AU wanted to - Micro-catheter clogging due to unusually large treat left lobe number of microspheres being used
- Identified after completion of the procedure - Prescribed activity was at high end of the treatment
- AU did not indicate correct treatment site on written range directive; AU did not forward pre-treatment - Patient administration delayed 1 day - 25% increase information to the RSO in number of microspheres were needed to deliver
- Clinical staff failed to identify discrepancy during the dose patient time-out just before the implantation - Will use smaller aliquots and/or slower infusion rate 59 60 15
35.1000 Y-90 SirSphere Events 35.1000 Y-90 SirSphere Events Device malfunctioned 1
- Prescribed 19.6 mCi to left lobe of liver, but
- Prescribed 32.5 mCi but received 8 mCi - 25% of received 10 mCi - 51% of activity activity - Planned to deliver activity in two split dosages
- Treatment device malfunctioned and ceased to - Written directive not properly reviewed, so split one deliver microspheres dosage in two instead of the total dosage in two
- Manufacturers representative was present, but cause - Radiation oncologist failed to check the drawn of malfunction is unknown dosages prior to injecting them
- Will return delivery device to manufacturer for - Identified after injection when the remainder of the technical analysis and root cause determination dosage was discovered 61 62*
35.1000 Y-90 SirSphere Events Acronyms
- Prescribed 19.6 mCi to left lobe of liver, but
- AU - Authorized User received 10 mCi - 51% of activity (cont.)
- cGy - centiGray
- Lack of comprehension of dose draw worksheet
- FY - Fiscal Year
- Miscommunication and failure to review the written
- GBq - Giga Becquerel directive
- HDR - High Dose Rate Remote Afterloader
- Failure to perform a safety pause and properly review
- I-131 - Iodine-131 the dosage to be administered against the written directive prior to the administration
- I-124 - Iodine-124
- IVB - Intravascular Brachytherapy
- MBq - Mega Becquerel 63 64 16
- µCi - microcurie
- mCi - millicurie
- MIBG - Metaiodobenzylguanidine
- Pd-103 - Palladium-103
- RSO - radiation safety officer QUESTIONS?
- SI units - International System of Units
- Y Yttrium-90 65 66 17