ML23125A317
| ML23125A317 | |
| Person / Time | |
|---|---|
| Issue date: | 05/05/2023 |
| From: | Dimarco D NRC/NMSS/DMSST/MSEB |
| To: | |
| D. DiMarco | |
| References | |
| Download: ML23125A317 (78) | |
Text
Status of Medical Events FY 2022 Daniel DiMarco Medical Radiation Safety Team May 15, 2023
Medical Events The dose threshold for diagnostic events precludes reportable events most years.
Each year, there are approximately 150,000 therapeutic procedures performed utilizing radioactive materials.
2
Medical Events FY 2017 - 2022 FY17 FY18 FY19 FY20 FY21 FY22 35.200 0 0 1 (8*) 0 4 0 35.300 4 2 9 2 10 10 35.400 7 11 (13*) 5 6 4 1 35.600 8 (14*) 10 9 (10*) 13 5 11 (40*)
35.1000 24 25 (26*) 32 27 41 34 Total 43 48 56 48 64 56
- The total number of patients involved if greater than the number of reports 3
Medical Events 2022 35.200 Medical events 0 4
Medical Events 2022 35.300 Medical events 10 Lutetium-177 4 I-131 NaI 3 Ra-233 2 Ac-225 1 5
35.300 I-131 NaI
- Patient overdose [210490]
- Patient prescribed 0.074 GBq (2mCi), received 5.62 GBq (152 mCi)
- Patient intended to receive 5.55 GBq (150 mCi), signed in medical record
- Error in computer-generated written directive
- No harm because intended treatment was administered
- Corrective actions included changes to computer-generated written directive and procedure changes to existing timeout process 6
35.300 I-131
- Patient underdose [210455]
- Prescribed 3.7 GBq (100 mCi), administered 2.9 GBq (78.5 mCi)
- Therapeutic portion of a sponsored study protocol
- Fixed activity administration limited by kidney dose, no reliable dose estimate for the prostate
- Root cause determined to be inadequate training on protocol
- Corrective actions included additional training
- No adverse impacts were expected
- Follow-up doses were cancelled due to proximity to kidney dose constraints 7
35.300 I-131
- Patient underdose [210448]
- Patient prescribed 925 MBq (25 mCi), received 370 kBq (10 µCi)
- Administered I-131 capsule, was unable to swallow and pill broke down in mouth
- Capsule was removed and taken to safe room
- Some removed pharmaceutical leaked, leading to a contamination incident
- Second administration of liquid I-131 attempted the next day, patient also failed to swallow
- Dose from first administration estimated by bioassay
- Corrective actions included having patients swallow a placebo pill prior to administration
- No persons were determined to be contaminated; decontamination of surfaces was successful 8
35.300 Lu-177 Lutathera
- Patient overdose [220331]
- Prescribed 3.7 GBq (100 mCi), administered 7.62 GBq (206 mCi)
- Patient had kidney disease, requiring the smaller dosage
- Administering tech did not receive the written directive from NM Dept
- Pharmacy tech drew typical dosage of 7.4 GBq (200 mCi), did not consult written directive
- Root cause was determined to be failure to follow established protocols and lack of communication within department
- Corrective actions included a daily huddle to communicate key information about the days therapy patients
- Additionally, the secondary verification now requires a physical signature on the written directive
- Patient will be followed to assess for kidney damage 9
35.300 Lu-177 Lutathera
- Patient overdose [220328]
- Prescribed 3.7 GBq (100 mCi), administered 7.62 GBq (206 mCi)
- Third of four treatments, previous treatments also prescribed 3.7 GBq (100 mCi) due to reduced creatinine clearance
- Delay in treatment due to suspension of radioisotope production
- Resulted in adequate creatinine levels for the treatment, doses to non-target tissues was in line with parameters for a standard treatment
- Final treatment was planned to be either a full or half dose, depending on patient tolerance
- Written directive was updated to improve verification process of dose measurement 10
35.300 Lu-177 Lutathera
- Patient underdose [220128]
- Patient prescribed 7.62 GBq (206 mCi), received 1.48 GBq (40 mCi)
- Two minutes after infusion, leak was noticed in line
- Procedure stopped and vial and tubing assayed
- Wipe tests showed no patient contamination
- Room was surveyed and appropriately decontaminated
- Root cause was equipment failure, corrective actions were implemented
- No clinical impact or risks to the patient 11
35.300 Lu-177
- Patient underdose [220114]
- Patient prescribed 7.4 GBq (200 mCi), received 0.052 GBq (1.4 mCi)
- Vial lost pressure during treatment
- Remedial measures attempted but failed
- No contamination found
- No adverse effects noted 12
35.300 Ra-223
- Patient overdose [220338]
- Patient prescribed 2.13 MBq (57.5 µCi), received 6.84 MBq (184.9
µCi)
- Clerical error in written directive, patient received intended dose 13
35.300 Ra-223 Xofigo
- Patient underdose [220340]
- Patient prescribed 7.83MBq (211.6 µCi), received 5.92 MBq (160
µCi)
- Leakage occurred in three-way stopcock during administration
- Administered dose estimated by measuring the leaked radiopharmaceutical
- Root cause was determined to be incorrect cap used on the unused port
- Corrective actions included procedure revisions to prevent leakage and additional training
- No harm is expected to the patient 14
35.300 Ac-225
- Patient underdose [210503]
- Patient prescribed 5.55 MBq (150 µCi), received 4.22 MBq (114
µCi)
- Clinical trial for prostate cancer
- Accidental discharge onto absorbent pad
- Root cause determined to be the recession of the connection point into the tungsten shield, hindering operation of the three-way stopcock
- AU removed connection without required three saline flushes
- Corrective actions included retraining of all AUs, refresher training on written directives, and acquisition of an alpha detector to survey for contamination 15
Medical Events 2022 35.400 Medical events 1 Eye Plaque 1 16
35.400 I-125 Eye Plaque
- Patient underdose [210459]
- Prescribed 8,500 cGy (rad), received 1,695 cGy (rad)
- Plaque held 30 seeds with an activity of 49.21 MBq (1.33 mCi) in each seed
- Plaque dislodged while patient rubbed eye
- Plaque placed in lead pouch and returned to AU
- No corrective actions taken 17
Medical Events 2021 35.600 Medical events 11 HDR 10 PDR 1 18
35.600 HDR
- Patient overdose [220167]
- 333 GBq (9 Ci) I-192 HDR Unit
- Prescribed 10 HDR treatments, following four treatments the licensee noticed some source catheters had been mislabeled
- Planned skin dose was 26.5 Gy (2650 rad), after adjustments the dose to skin was 48.4 Gy (4840 rad)
- No adverse effects expected but patient will have more frequent follow-up
- Root cause determined to be human error and lack of proper catheter identification
- Corrective actions included procedure updates to emphasize catheter identification and modification of planning process to include an additional review by a second physicist
- Staff also received additional training 19
35.600 HDR
- Patient underdose [220186]
- 370 GBq(10 Ci) Ir-192 HDR unit
- 2 patients both prescribed 4 fractions of 7 Gy (700 rad) for a total of 28 Gy (2800 rad)
- First patient had an underdose in fraction 2 of 4, only 79.1% of he fraction was delivered
- Second patient had an underdose in fraction 4 of 4, only 54.4%
of the fraction was delivered
- Additionally, this patient received a 48% greater dose to the rectum for this fraction, resulting in a 15.4% greater dose to the rectum for the full treatment 20
35.600 HDR
- Patient underdose [220186] (cont.)
- Radiation therapist replaced a catheter with one that was an incorrect length
- Procedures required a blue catheter with a 1377 mm length, but the new blue catheters are longer than this and must be trimmed down to the correct length
- Corrective actions included procedure modifications to ensure the correct catheter is of appropriate length, and additional training
- Patient one had modifications to the rest of the treatment to compensate for the underdose, patient two had no adverse effects 21
35.600 HDR
- Patient underdose [210482]
- 277.5 GBq (7.5 Ci) Ir-192 HDR unit
- Patient prescribed 1400 cGy (rad), administered 1020 cGy (rad)
- Error message 8C.2 - Dummy park switch or drive failure displayed during treatment after first 15 channels were delivered
- Field service engineer suggested reboot of system, not successful
- AU stopped treatment to avoid leaving patient under general anesthesia, leaving remaining four channels untreated 22
35.600 HDR
- Patient underdose [210512]
- 221.26 GBq (5.98 Ci) Ir-192 HDR unit
- Prescribed 1500 cGy (rad), received 50 cGy (rad)
- Patient was treated without issue through first channel
- Error at the start of the second channel, indicating the source position slipped at 0.0 cm mark
- Treatment paused and test wire was run, no errors indicated
- Second attempt at treatment returned the same error, treatment was cancelled
- Source was verified to be in the unit and no additional dose was delivered to the patient or staff
- Service engineer determined a hardware issue with the active source encoder, which serves as a second check for the movement of the source
- Encoder replaced, HDR unit determined operational 23
35.600 HDR
- Wrong site [220085]
- 237.58 GBq (6.421 Ci) HDR unit
- Patient intended to receive 600 cGy (rad) to lower third nasal dorsum
- Patient prescribed 600 cGy (rad) to right nasal sidewall
- No adverse effects expected 24
35.600 HDR
- Wrong site [220261]
- HDR Unit
- Prescribed 3600 cGy (rad) to the skin of the left scalp
- Physician misidentified the treatment site, photos taken after biopsy but had healed when trying to identify prior to treatment
- Potential consequences determined to be potential to develop skin cancer at the treated site in 20-30 years and recurrence of the cancer at the untreated site 25
35.600 HDR
- Wrong site [220261] (cont.)
- Patient was offered additional treatment to the carcinoma. But chose observation by dermatologist
- Corrective actions included creation of an HDR planning policy for dermal brachytherapy
- Updated commitment to policy to state that HDR skin cancer sites will be reviewed at a peer review meeting before treatment
- Better photographs of the treatment site will be taken and ambiguous information will require additional verification 26
35.600 HDR
- Wrong site [220275]
- 177.6 GBq (4.8 Ci) I-192 HDR Unit
- Patient has two lesions on the lower right leg
- First was treated using SBRT without incident
- Second prescribed 4000 cGy (rad) over 8 fractions
- First fraction, 500 cGy (rad), unintentionally delivered to the first lesion
- Discovered when the patient noticed the planning circle had been drawn over the first lesion before the second fraction
- No adverse effects are expected 27
35.600 HDR
- Wrong site [220275] (cont.)
- Root cause was determined to be human error, particularly failure to notice the change in positioning from supine to prone
- Contribution factors were the proximity of the 2 lesions (1.5 in apart) and that the second lesion was not present during the previous SBRT treatment
- Corrective actions included adding a pretreatment step for multiple, close lesions, asking the patient to point to the treatment site, and using more verification images of the treatment site 28
35.600 HDR
- Wrong site [210537]
- 277 GBq (7.485 Ci) Ir-192 source
- Prescribed 2100 cGy (rad), delivered in three 700 cGy (rad) treatments
- First fraction delivered
- Some point after patient experienced complications from a hysterectomy, treated at a different hospital
- Did not return for other treatments
- Oncologist at new hospital determined that the first treatment was off by 3 cm
- Colon and bowel received dose of 700 cGy (rad)
- Corrective actions included procedure modification to require CT imaging/review after insertion of HDR applicators 29
35.600 HDR
- Wrong site [220026]
- 436.97 GBq (11.81 Ci) Ir-192 HDR unit
- Patient received a single 250 cGy (rad) fraction to the left hand, instead of the right hand as prescribed
- Corrective actions included immediate discussion with all clinical staff to verify correct anatomical treatment site regarding all prescriptions 30
35.600 HDR
- Wrong site [220308]
- 370 GBq (10 Ci) I-192 HDR Unit
- Deviation in transfer tube by 2.9 cm discovered, affecting 27 patients
- Dose to the unintended tissue was determined by recreating the intended plan and comparing to a transfer tube shifted plan
- Resulted in 267 cGy (rad) of additional dose to unintended tissues per fraction
- Investigation and corrective actions still ongoing 31
35.600 PDR
- Patient underdose [220224]
- 37 GBq (1 Ci) PDR unit
- Three patients
- 2982 cGy (rad) prescribed, 256.7 cGy (rad) delivered
- 36.21 cGy (rad) prescribed, 12.07 cGy (rad) delivered
- 37.28 cGy (rad) prescribed, 16.72 cGy (rad) delivered
- Discrepancy between measured treatment distance and treatment plan
- Root cause determined to be erroneous manual entry in reference table (1248 mm entered vs. 1448 mm intended)
- Corrective actions included root cause analysis, procedure modification, and additional reference table verification 32
Medical Events 2022 35.1000 Medical events 34 GSR 2 Y-90 Microspheres
- TheraSphere' 23
- SIR-Spheres 7 33
35.1000 Gamma Knife
- Wrong site [220241]
- Patient prescribed between 20 and 21 Gy (2000 to 2100 rad) to four lesions in the brain
- Post treatment, discovered that the targeting had been off by 0.5 cm for all lesions
- Delivered dose to lesions between 8 and 15 Gy (800 to 1500 rad)
- Max dose range to unintended healthy tissue was 21.82 to 27.09 Gy (2182 to 2709 rad) 34
35.1000 Gamma Knife
- Wrong site [220241] (cont.)
- Root cause was shifting of coregistration of images between intended target and treatment parameters
- Discovered after surgery
- No adverse effects are expected but patient will be monitored
- Corrective actions included updated treatment procedures to include review and approval of treatment plan by two of three team members that involve coregistration of CT/MRI images 35
35.1000 Gamma Knife
- Wrong site [220484]
- Patient treated for 10 brain lesions, patient fell asleep during treatment of first 4 lesions
- Patient woke up for the fifth treatment but no sufficient movement was recorded to stop/delay treatment
- Treatment later paused to allow the patient to use the restroom, during which the therapist noticed the frame had moved from its original position
- Remainder of the treatment was cancelled, new CT was performed, and new treatment plan was developed for the remaining 4 lesions, which were treated without incident
- Review of the treatment indicated that 4 lesions were treated initially, 2 followed the patient waking up, and the remaining 4 were treated after the re-planning 36
35.1000 Gamma Knife
- Wrong site [220484] (cont.)
- Potential effects were determined on a most likely and worst-case scenario
- Most likely - only 2 lesions affected by movement
- Worst-case - 6 initial lesions affected by movement
- In the most likely scenario, the two lesions received slightly more dose due to a slightly higher volume of brain tissue exposed and there was no effect on the other lesions
- In the worst-case scenario, two lesions would be underdosed by over 50% and would have significantly high risk of recurrence
- The patient has been followed and has shown no detrimental effects from this event
- This event is still under investigation 37
35.1000 TheraSphere'
- Y-90 TheraSphere' overdose [220181]
- Patient prescribed 2.228 GBq (60.22 mCi), received 2.84 GBq (76.7 mCi)
- When administering microspheres to three liver segments, it was determined that the segment had been misidentified due to variant anatomy
- Segment 7 received more dose than expected but all three targets had received an appropriate segementectomy dose
- Root cause was determined to be failure to identify variant anatomy during treatment
- Corrective actions included secondary review of pre-treatment mapping and angiography of any administration where the location of the catheter is questioned
- If this is not effective, the AU will perform a 3d cone beam CT to confirm the area to be treated
- No adverse effects were expected 38
35.1000 TheraSphere'
- Y-90 TheraSphere' overdose [210494]
- Patient prescribed 2 administrations to different segments of the liver, 1 GBq (27 mCi) and 2.72 GBq (73.4 mCi)
- Administered 2.18 GBq (59 mCi) and 4.4 GBq (119 mCi) respectively
- The doses had been ordered with an incorrect calibration date
- Root cause was determined to be a failure to confirm the calibration date and a failure to check the that the prescribed dose matched the measured dose during pre-treatment checks
- Patient was followed and no adverse effects were noted
- Corrective actions included updating Y-90 worksheets to add a new verification of dose-in-hand rather versus the written directive, and an update to the dose ordering process requiring a second person to give their signature
- Personnel were trained on these new procedures 39
35.1000 TheraSphere'
- Y-90 TheraSphere' overdose [220207]
- Patient prescribed 1.94 GBq (52.43 mCi), received 2.81 GBq (75.95 mCi)
- Patient intended to receive 2 vials of microspheres for the administered dose
- WD erroneously accounted for only one vial
- Administered activity was within 2% of planned activity
- Root cause was determined to be human error
- Corrective actions included personnel training and procedure updates 40
35.1000 TheraSphere'
- Y-90 TheraSphere' overdose [220173]
- Patient prescribed 0.355 GBq (9.6 mCi), received 2.17 GBq (58.6 mCi)
- Two patients were due to receive Y-90 treatment on the same day
- Patient A with 2 vials, Patient B with 3 vials
- Patient A was prescribed 0.355 GBq (9.6 mCi) and 1.3 GBq (35.2 mCi), but the first vial was mistakenly swapped with one of Patient Bs vials
- The WD prescribed 12,000 cGy (rad) to segments 2 and 3 but received 73,660 cGy (rad)
- This dose was considered clinically acceptable, and no adverse effects are expected
- Patient Bs treatment was cancelled 41
35.1000 TheraSphere'
- Y-90 TheraSphere' overdose [220173]
(cont.)
- Corrective actions included requiring a signed verification of dose activity by two techs, with a temporary requirement that one be a supervisor or manager
- Additionally, all dose vials are now required to be re-verified in the vent of handoff between certified NMTs
- Y-90 standard operating procedure was revised and all staff and Aus were trained on the updates
- For 90 days following the event, a supervisor checked the cart, documentation, and calibration instrumentation for accuracy prior to transport to the IR suite
- Monthly audits occurred for 90 days to determine effectiveness of these actions, after which quarterly audits continued 42
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210491]
- Patient prescribed 1.3 GBq (35.1 mCi), received 0.533 GBq (14.4 mCi)
- Vial septum failed under pressure during administration
- No effects were expected
- Root cause was determined to be failure to develop, implement, and maintain procedures
- Corrective actions included revision of procedures to specify the correct needle gauge and revision of emergency procedures 43
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210480]
- Patient prescribed 1.66 GBq (44.8 mCi), received 0.692 GBq (18.7 mCi)
- Physician noted that there was greater resistance during administration but no stoppage occurred due to intervention or patient
- Tubing and connections were checked, no cause for the resistance was found
- Overflow bottle did overflow but no activity was measured
- Dose rate at vial was zero after administration and no contamination was found 44
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210480]
(cont.)
- Investigation found that microspheres had built up at the distal and proximal ends of the catheter, but no reason could be found
- Manufacturer noted that the catheter was within the recommended size
- Corrective actions included more flushes during treatment 45
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220054]
- Patient prescribed 1.45 GBq (39.24 mCi), received 1.03 GBq (27.72 mCi)
- Treatment proceeded without incident, but post-treatment survey of waste revealed 0.43 GBq (11.52 mCi) of Y-90
- No contamination was detected
- No adverse effects are expected 46
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210529]
- Patient prescribed 4.08 GBq (110.27 mCi), received 2.57 GBq (69.46 mCi)
- Treatment proceeded without incident
- Post-treatment surveys revealed residual activity and gave estimates of the administered dose
- Root cause was determined to be flow issue in the microcatheter, causing the microspheres to precipitate out
- No adverse effects to the patient are expected 47
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220182]
- Patient prescribed 379.99 MBq (10.27 mCi), received 260.11 MBq (7.03 mCi)
- AU noticed sluggish flow during first saline flush, possibly due to kinking in the microcatheter
- No contamination was identified, and the AU was satisfied with the dose delivered
- Root cause was determined to be small treatment volume and small vessel treated
- More than 30 psi is required to push microspheres into small vessels, but the built-in pressure valve did not apply pressure greater than 30 psi
- No adverse effects were expected 48
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220264]
- Patient received only 26% of prescribed dose
- Treatment went according to plan, post-treatment surveys revealed that microspheres did not come out of the tubing as designed
- All proper procedures were followed, no kinks in tubing could be identified, and the AU had used a larger catheter than required
- Over 70% of the microspheres remained in the delivery device
- No root cause could be identified but investigations determined that the most likely cause was equipment failure
- No corrective actions were identified 49
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220390]
- Patient prescribed 44,000 cGy (rad), received 35,180 cGy (rad).
- During preparation, oncology nurse expelled some liquid onto gauze to remove bubbles from the treatment tubing
- The loss of activity resulted in a smaller delivered activity
- No adverse effects were expected, and no additional dose was needed
- Investigation determined that proper procedure had been followed and it was not clear whether the vent was caused by human error or product defect 50
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220387]
- Patient prescribed 1.27 GBq (34.4 mCi), received 111 MBq (3 mCi)
- Procedure was halted prematurely, and surveys of the waste and room were taken
- No contamination was found, and microspheres were observed clustered in the hub
- Correct microcatheter was used
- Waste survey was used to approximate dose delivered
- Root cause was determined to be microsphere clumping between lines E and D in the kit 51
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220410]
- Patient prescribed 1.77 GBq (48 mCi), received 1.05 GBq (28 mCi)
- Microspheres clumped in catheter and AU was unable to administer the full dose
- Root cause was determined to be a microcatheter with a curved tip that ended up at the vessel wall, blocking the flow of microspheres
- Corrective actions included discontinuing use of that type of microcatheter 52
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210493]
- Patient prescribed 1.26 GBq (34.1 mCi), received 0.895 GBq (24.2 mCi)
- Surveys after the administration noted that microshperes were held up in the catheter
- Root cause was determined to be clumping of microspheres in the catheter due to problems in the procedure
- A copy of IN-19-12 was provided to understand the issue and help prevent future incidents 53
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210486]
- Patient prescribed 3 GBq (81.08 mCi), received 1.96 GBq (52.90 mCi)
- Surveys of the container revealed a higher than expected dose after the administration
- Delivery kit was shipped to manufacturer after decay
- Root cause was determined to be intentional use of a smaller catheter than advised (0.3mm), resulting in microspheres being held up in the line
- Physician determined that the dose delivered was effective
- No corrective actions were taken 54
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [210500]
- Patient prescribed 809.93 MBq (21.89 mCi), received 509.86 MBq (13.78 mCi)
- One of four treatments to different lobes of the liver
- Three other treatments had no complications
- Physician attempted to use 2.0 Fr. Truselect microcatheter for an hour to access artery but was unsuccessful
- Fell back on a 1.7 Fr. Echelon microcatheter, where some of the microspheres were held up in the smaller catheter
- Other treatment options were considered, but the decision to use the smaller catheter was determined by the physician to be medically necessary
- No adverse effects are expected and no corrective actions were put in place 55
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220039]
- Patient prescribed 1.93 GBq (52.16 mCi), received 0.49 GBq (13.24 mCi)
- Treatment was prematurely terminated due to unwinding of male Leur lock connector
- A second WD was created to compensate for the underdose and this treatment was successful
- Information of this event was circulated to all impacted licensees
- Root cause was determined to be a defective Leur lock
- The event was not reported initially due to insufficient WD procedures
- Corrective actions included casing use of the affected administration set 56
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220021]
- Patient was successfully administered two doses of microsphere but the third only administered 5% of the dose
- The microspheres were caught up in the tubing from the vial 57
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220127]
- Patient prescribed 2.93 GBq (79.19 mCi), received less than 1% of prescribed
- AU noticed resistance during administration and halted the treatment
- Microspheres were observed clumped in the first 2 in of the delivery catheter
- Second dose ordered and delivered successfully
- No contamination was identified
- Root cause was determined to be use of a catheter smaller than the recommended catheter by the manufacturer
- Corrective actions included discontinuation of microcatheters with inner diameter smaller than 0.5 mm in accordance with recommendations
- No adverse effects to the patient were expected 58
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220091]
- Patient prescribed 0.51 GBq (13.78 mCi), received 0.16 GBq (4.32 mCi)
- Discovered during a review of microsphere procedures, licensee incorrectly assumed this was not reportable because they revised treatment plan and WD after treatment
- Root cause was determined to be use of a smaller than recommended catheter
- AU stated that dose was medially satisfactory and then smaller diameter catheter was necessary to treat the patient
- Corrective actions included providing additional training to staff 59
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220087]
- Patient prescribed 0.3 GBq (8.11 mCi), received 0.11 GBq (2.97 mCi)
- Discovered during a review of microsphere procedures, licensee incorrectly assumed this was not reportable because they revised treatment plan and WD after treatment
- Root cause was determined to be use of a smaller than recommended catheter
- AU stated that dose was medially satisfactory and then smaller diameter catheter was necessary to treat the patient
- Corrective actions included providing additional training to staff 60
35.1000 TheraSphere'
- Y-90 TheraSphere' underdose [220190]
- Patient prescribed 12,000 cGy (rad), received 9,420 cGy (rad)
- Stasis was not reached, and no apparent cause was identified
- Au had written that 12,000 cGy (rad) was the desired dose on the WD, but the dose received from the manufacturer had a maximum expected dose of 11,000 cGy (rad)
- If the WD had been updated with this dose, then the administration would have not tripped the ME criteria
- Corrective actions included training to WD updates 61
35.1000 TheraSphere'
- Y-90 TheraSphere' wrong site [220296]
- Patient prescribed 1.45 GBq (39.2 mCi) to the right lobe of the liver for 14,800 cGy (rad), received 24,000 cGy (rad) to the left lobe of the liver
- Root cause was determined to be variant anatomy
- Patient was brought back in to treat the correct lobe of the liver 62
35.1000 SIR-Spheres
- Patient prescribed 2.2 GBq (59.46 mCi), received 5.07 GBq (137 mCi)
- NM ordered a full unit dose and mistakenly administered the full dose during the treatment
- Dose was not verified prior to administration and WD was incorrectly filled out with received and ordered doses
- Root cause was determined to be human error
- Corrective actions included implementation of a new procedure 63
35.1000 SIR-Spheres
- Patient prescribed 0.4 GBq (10.81 mCi) and 1.6 GBq (43.24 mCi), received 0.51 GBq (13.78 mCi) and 2.19 GBq (59.19 mCi)
- A calculational error occurred when converting from GBq to mCi, resulting in the larger doses
- Corrective actions included an updated WD that explicitly lists the conversion factor from GBq to mCi, and the conversion to be performed by the NMT not just the manufacturer representative
- No adverse effects were identified or expected 64
35.1000 SIR-Spheres
- Patient prescribed 0.5 GBq (13.51 mCi), received between 0.386 (10.43 mCi)
- Root cause was determined to be a clogged catheter
- Corrective actions included implementation of a new quality management plan
- No adverse effects are expected 65
35.1000 SIR-Spheres
- Patient prescribed 599.4 MBq (16.2 mCi), received 469.9 MBq (12.7 mCi)
- Error discovered during post-treatment calculations
- No root cause could be determined
- No adverse effects were expected 66
35.1000 SIR-Spheres
- Patient prescribed 370 MBq (10 mCi), received 230.51 MBq (6.23 mCi)
- Prior to treatment, contrast was injected and no leakage was observed
- During the administration, the doctor noticed a small leak at the Leur lock connection
- The Radiation Safety staff was notified and the doctor tightened the connector and continued the procedure after changing gloves
- The remainder of the microspheres were administered without incident
- Contaminated materials were then removed and surveyed to estimate the dose not delivered 67
35.1000 SIR-Spheres
(cont.)
- The room was surveyed and found to have no contamination
- Root cause was determined to be a lack of clear written instructions in the procedures
- Corrective actions included an update to the procedures to include steps for checking the connections to the delivery system
- No adverse effects were expected 68
35.1000 SIR-Spheres
- Patient prescribed 261.59 MBq (7.07 mCi), received 194.99 MBq (5.27 mCi)
- Apparent cause was complicated patient vasculature, inhibiting flow of microspheres
- No adverse effects were expected 69
35.1000 SIR-Spheres
- Patient prescribed 3.25 GBq (87.84 mCi), received 1.55 GBq (41.89 mCi)
- Procedure was halted due to occlusion of microspheres in delivery line
- This treatment was the largest ever dose to date at this treatment facility
- The vial was at maximum volume and the fluid appeared highly viscous
- Root cause was determined to be too many microspheres in the vial to be properly agitated or a dysfunctional stop cock
- Corrective actions included modification of procedures to split large doses into 2 separate vials
- Patient was administered another dose to compensate, no adverse effects expected 70
35.1000 SIR-Spheres
- Patient prescribed 299.7 MBq (8.1 mCi), received 233.1 MBq (6.3 mCi)
- Procedure occurred without incident, no stasis
- Investigations determined that a member of the staff noticed a blob of microspheres close to the vial before dose delivery
- Manufacturer was notified and recommended gentle shaking of the vial before delivery
- AU determined that the dose delivered was effective
- Corrective actions included checking the vial prior to delivery and following manufacturer recommendations to shake the vial gently if accumulation is observed
- No adverse effects were expected 71
35.1000 SIR-Spheres
- Patient prescribed 185 MBq (5 mCi), received 135.79 MBq (3.67 mCi)
- Remaining microspheres held up in delivery system
- Investigation noted that the dose was unusually small compared to previous procedures
- The amount of remaining microspheres was approximately the same as in previous procedures, but the smaller size of the initial dose resulted in a reportable underdose
- Corrective actions included additional saline flushes to minimize residual microspheres and the addition of 20% more activity for low dose prescriptions (<370 MBq (10 mCi)) to account for anticipated residual microspheres
- Additionally, the licensee implemented more frequent monitoring of hands-on personnel to identify potential contamination
- No adverse effects were expected, and no additional dose was required 72
Summary
- 35.300
- Delivered intended dose but incorrect WD
- Full dose administration of Lu-177 but reduced dose on WD
- Ac-225 difficulties with lead shielded syringe, resulting in leakage 73
Summary
- 35.600
- 4 misidentified lesion sites
- Use of incorrect tube/catheter lengths
- Multiple patients affected by single medical event, catheter/tube length problems 74
Summary
- 35.1000
- Primarily Theraspheres, primarily underdoses
- 4 events due to use of smaller than recommended catheters
- 2 events due to malfunctioning Luer locks
- 2 events due to unusually small doses
- 3 of 6 overdose events were due to incorrect WD 75
- µCi - microcurie
- AMP - authorized medical physicist
- AU - Authorized User
- Cs-131 - Cesium-131
- cGy - centiGray
- CT - Computed tomography
- FY - Fiscal Year
- GBq - Giga Becquerel
- Gy - Gray
- HDR - High Dose Rate Remote Afterloader 76
- I-192 -Iridium-192
- IVB - Intravascular Brachytherapy
- MBq - Mega Becquerel
- µCi - microcurie
- mCi - millicurie
- NMT - Nuclear medicine technician
- RSO - radiation safety officer
- SI units - International System of Units
- WD- Written Directive
- Y Yttrium-90 77
QUESTIONS?
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