On 1/28/04, the patient was to receive a total dose of 50.4 Grays to the 'vaginal cuff' region using a 6 Curie
Ir-192 sealed source. The dose was to be administered using a Microselectron Remote Afterloader
HDR manufactured by Nucletron, serial number 31021.
The plan was to administer 3 radiation treatments using a catheter that is 1500 millimeters (mm) long. The treatment planning software system uses a default value of 995 mm for the catheter length. When preparing the treatment plan for the first of the 3 planned radiation treatments, the medical physicist did not notice that the catheter length in the treatment plan was incorrect (995 mm instead of the actual 1500 mm catheter that would be used). When the radiation oncologist and the medical physicist were doing a pretreatment review and ensuring that the important parameters of the planned treatment were correct, they did not check the catheter length in the treatment plan to ensure that it was correct.
The first radiation treatment was conducted, but instead of the radiation source traveling approximately 1500 mm in the catheter and providing radiation treatment to the 'vaginal cuff' region on the patient, it traveled only about 995 mm, and never entered the patient's body. When the medical physicist began to plan the second of the three radiation treatments, he noticed the error in the treatment plan for the first treatment. The radiation oncologist notified the patient on the same day the error was discovered.
The records of all patients previously treated by this medical physicist and radiation oncologist were reviewed to determine if a similar error had occurred during any other high dose rate remote afterloader treatments, but no other errors of this type were found. To prevent future errors, both the medical physicist and the radiation oncologist have reviewed the treatment planning software and have agreed on a program of formal cross checking of the pretreatment printout that would include verifying that the catheter length specified in the treatment plan is correct.