ENS 45933
ENS Event | |
|---|---|
07:00 May 16, 2010 | |
| Title | Agreement State Report - Potential Radiation Underdose |
| Event Description | The following report was received via email from the State of Nevada:
On March 16, 2010, during a prostate Brachytherapy procedure, 112 sources of I-125 (Model I125-SL[NIST 99]), were implanted into the prostate. The activity of each source was 0.342mCi. Total prescribed dose was 145 Gy. When the patient returned for follow-up, 1 to 2 months after the implant, CT images were imported into the treatment planning system and a post-plan was created to assist in quality assurance, to determine the actual dose to the prostate and to review the overall quality of the implant. When the post-plan was created for this patient and reviewed, it was determined that the dose to the prostate was approximately 114 Gy, which was 79% of the prescribed dose. This exceeds the +/- 20 % limit set in 10 CFR 35.3045. The physician was notified and the dosimetry reviewed. The lower dose was in the middle, close to the urethra where there is a desire for dose sparing. The higher doses were on the periphery of where the dose was intended. Following normal protocol, the patient's blood work will be monitored to observe his PSA levels. The referring physician was contacted on May 14, 2010. The patient has not been informed. Contributory Factors: Though not known as to why the dose was lower than prescribed, it appears that the seeds were implanted more in the periphery probably due to a desire to spare the urethra. This could have been due to the urethra-gram performed during surgery. Consequences: The physician is of the opinion that the therapy will still be effective since the seeds were implanted where statistically the cancer resides. The patient's blood work will be monitored regularly and additional therapy given, if necessary. Corrective measures: Care will be taken to ensure that the sources are evenly distributed throughout the prostate in the future. It was the physician's desire to spare the urethra. It will be under the discretion of the physician as to how to implant the prostate and still deliver the desired prescribed dose. Notification: The patient's plan/dosimetry was presented to the Physicist and the Physician on May 13, 2010 at 3.00 p.m., the State of Nevada Radiation Control Program was contacted by phone on May 14, 2010 at 9.00 a.m. This is NV event #NV100010. A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient. |
| Where | |
|---|---|
| St Mary'S Regional Medical Center Reno, Nevada (NRC Region 4) | |
| License number: | 16-12-0244-02 |
| Organization: | Nv Div Of Rad Health |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+31.97 h1.332 days <br />0.19 weeks <br />0.0438 months <br />) | |
| Opened: | Sneha Ravikumar 14:58 May 17, 2010 |
| NRC Officer: | Eric Simpson |
| Last Updated: | May 17, 2010 |
| 45933 - NRC Website | |
St Mary'S Regional Medical Center with Agreement State | |
WEEKMONTHYEARENS 459332010-05-16T07:00:00016 May 2010 07:00:00
[Table view]Agreement State Agreement State Report - Potential Radiation Underdose 2010-05-16T07:00:00 | |