F A Bombardiere | PubMed Health

PubMed1990

Table-sag errors in CT treatment planning.

It is common practice to utilize CT scans in place of patient contours for computerized treatment planning. Our experience, in particular with pelvic patients, is that setting up the patient for a CT scan using landmarks from a radiation therapy simulator does not always produce accurate field margins. In general, the treatment field center as produced by the CT scan is superior to the center as defined by the simulator film. We have determined this problem to be caused by simulator table sag as compared to the CT. We offer suggestions to correct the problem.

Humans↗

PubMed1989

Machine specific equivalent squares for two commonly employed blocked treatment fields.

In an attempt to find the most suitable method for determining the equivalent square for two commonly employed blocked field arrangements, a comparison of measured outputs was made for four different treatment machines. The machines varied by manufacturer, design, and energy. The fields in question were a midline-blocked field and a half-blocked field. The data obtained was used to streamline calculations made by technologists for the original treatment setting. It was further used to enhance the accuracy of computer-generated verification of the original setting. The authors recommend that each institution employing such fields consider obtaining similar data for their own treatment machines.

Humans↗