|AGREEMENT STATE REPORT - MEDICAL EVENT
The following was received via report from the Florida Bureau of Radiation:
"On May 15, 2020 at 1530 EDT, the Bureau of Radiation Control (BRC) received a call from the medical physicist at the Lynn Cancer Institute regarding the following narrative which was received this morning, May 18, 2020 at 1000 EDT, from the Chief Medical Physicist. On May 12, 2020, a patient presented for a Vaginal Cylinder treatment utilizing the Elekta Ir-192 high dose rate remote afterloader. The written directive was initially written for 7 Gy [Ir-192] x 3 fractions to a depth of 0.5cm (5mm) and a 20mm diameter cylinder was chosen to treat the patient. Due to the relatively small diameter of the cylinder, the Radiation Oncologist decided to change the written directive to 7 Gy x 3 fractions to the surface of the cylinder. The treatment plan was created and the doses to the normal tissues (bladder, rectum and bowel) were accepted by the Radiation Oncologist and the treatment plan was subsequently approved. The approved treatment plan was then delivered to the patient.
"On May 14, 2020 it was discovered that the prescription isodose line did not appear to fall on the surface of the cylinder and on May 15, 2020, it was discovered that the 7 Gy isodose line was at about 4.2mm from the surface of the cylinder, and the dose to the points on the surface of the cylinder was found to be 158.3 percent of the prescription, on average. In the professional opinion of the Radiation Oncologist, the dose delivered did not negatively affect the patient and the doses to the normal tissues were acceptable dose levels for this type of treatment. It should be reiterated that the initial intent was to deliver the 7 Gy per fraction to a depth of 0.5cm (5mm) which would have fallen close to the 4.2mm at which the prescription dose was actually delivered. Additionally, had the plan been normalized to the surface of the cylinder the Radiation Oncologist would more than likely have increased the dose and he stated that the dose would have been too low for the intended treatment."
Incident Number: FL20-060
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.