[942361]
The patient had previous radiation therapy for anal carcinoma, stage iv when the pelvis and inguinal regions were treated and concurrent chemo was given. That treatment was not completed due to another illness. The patient missed the final seven radiation sessions. She returned to have para-aortic nodes irradiated. She refused additional tattoos at first. It was decided to use the previous pelvic tattoos for centering the patient and one additional abdominal tattoo was placed higher on the abdomen over the para-aortic region. The patient was to receive imrt treatment to the para-aortic region for a total dose of between 4500 and 5500 cgy. No chemo was used. A ct was done to use in setting up the simulation. Instructions were entered into the software in the tomo machine for this patient to let the therapist know that the pelvic tattoos were to be used for positioning only and the abdominal tattoo was to be used for therapy. The therapist failed to read the note and the pelvic tattoos were used exclusively leading to the dose going to an area 14 cm below the correct region. Protocol calls for the final approval of the region to receive therapy to be given by the physician and the physicist. In this case the original ct taken to set up the plan and the ct taken by the tomo were fused as expected but because one of the ct's was presented in an almost clear color, the fusion appeared correct when it was not. The other ct was presented in a light blue. Both the doctor and the physicist believed at the time that the fusion was correct and approved the plan. The patient received six doses in the incorrect area. A therapist then noted what looked like a poor fusion and believed the numbers were incorrect. She had the physicist look at the plan and the error was discovered. The tomo machine allows the ct to be almost changed to a clear color allowing the viewer to look at it and be able to almost look through it. This removes the effect of contrasting colors which adds to the risk of incorrect fusion. The software had recently been updated on the machine and the only specific training provided by the manufacturer was a cd to be viewed by staff. There was minimal mention of the use of the note function and also the effect of changing colors of the ct's.
Patient Sequence No: 1, Text Type: D, B5