The following was received from the State of Nevada via email:
The patient was prescribed ten [High Dose Rate Brachytherapy] treatments [with a 9.0 curie Ir-192 source]. After four treatments, it was discovered that some of the catheters had been incorrectly labeled. This altered the dose distribution resulting in a higher skin dose than anticipated, however the target dose difference did NOT exceed 50 percent from the prescription. The remainder of the patient's treatment was re-planned to compensate for the dose already given. The total doses once complete will be within limits for the skin and the target dose will be within 20 percent of the prescription. All treatments were to the correct patient and correct site.
The treatment area for this patient is adjacent to the skin, so the intended prescription would have given a skin max dose of nearly 100 percent of the prescribed treatment dose.
For the four treatments given with the incorrectly labeled catheters, the dose to skin is estimated to be 3 times the initially expected dose, exceeding 50 rem.
However, the patient's treatment was re-planned to provide additional skin sparing for the remaining treatments while maintaining minimum target coverage to compensate for the dose already given. We estimate the total skin dose from the entire treatment will exceed the initially anticipated skin dose by 41 percent. This total skin dose is still within standard protocol limits, and the written directive has been updated to be inclusive of the initial and new treatment plans and organ at risk (OAR) doses.
The patient and referring physician were notified the day the event was discovered before the determination that a medical event took place.
Nevada Event Number: NV220002