The following information was received via email:
The licensee reported a medical event at 0958 PST involving a patient treated for vaginal cancer. The treatment involved an Ir-192 high dose rate afterloader (HDR) source at 5.369 Curies activity (December 2nd) delivered to the vaginal vault via a 3 cm single-channel cylinder for a prescribed dose fraction of 400 cGy (rad). Instead, a 5 cm single-channel cylinder was used that delivered a 700 cGy dose (rad), or 75 percent (300 cGy) above the prescribed dose. The licensee stated that an afternoon patient's treatment plan was being reviewed on the console while the morning patient was being prepped for treatment and the patient subsequently treated with the other patient's plan. The licensee failed to verify the patient's identification before starting the treatment. The cause is therefore determined to be human error. The licensee stated that the patient was scheduled for three fractionated doses at 400 cGy (rad) each for a total dose of 1200 cGy (rad). This was the 2nd fraction so the total dose delivered to the patient is currently 1100 cGy (rad). The licensee performed a biological effective dose (BED) calculation and that the final effective dose is within 4 percent and 10 percent of the intended dose in terms of short/long term effects and the final fraction dose will most likely not be administered. The licensee notified the patient's physician who will notify the patient of the error. The licensee will submit a formal report to Oregon RPS including corrective actions to prevent recurrence.
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.