During a routine NRC inspection on 12/18/06 Sandra Gabriel Ph.D, Senior Health Physicist from Region I, discovered a medical event that occurred on 11/9/06 involving a
HDR (35.600) treatment.
On 11/9/06 an HDR treatment patient received a dose of 1.37 Gy to Point A when the prescribed intended dose was 6.0 Gy.
The following scenario lead to the medical event.
"A 6.0 cm tandem was inserted into the patient, however, the Authorized User asked the Authorized Medical Physicist to treat only a length of 4.0 cm to spare excess dose to normal structures. After the patient was treated, the Authorized Medical Physicist told the Authorized User he miscalculated the appropriate treatment length and what he thought was 2.0 cm from the end of the tandem was actually 20 cm from the tip of the tandem. The Authorized User and Authorized Medical Physicist calculated where 20 cm was, and this point was in fact outside of the patient's body, thus the patient only received dose from the ring portion of the applicator, resulting in a dose of 1.37 Gy to point A of the prescription plan.
Since this dose was subtherapeutic, the Authorized User added an extra HDR treatment (during the course of treatments) and the patient received a total dose to point A of 31.37 Gy which was within 20% of the original intended total dose. The patient was made aware of the extra treatment that was necessary because of the under dosage on 11/9/06.
A full written report will follow within 15 days as required by 10 CFR 35.3045.
- * UPDATE FROM FLANNERY (FSME) TO KOZAL AT 1213 ON 12/20/06 * * *
This event has been reviewed by the NRC medical review committee and determined to be a reportable medical event.
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.