The role of CT scanning in the radiotherapy planning of pelvic tumors.

In order to assess the place of computed tomography (CT) in radiotherapy planning, the tumor volumes are localized both by conventional techniques and with CT scanning under conditions simulating the radiotherapy. A comparison between the two methods has been made in a group of 55 patients with tumors in the pelvis. CT scanning was found to be of such value in 64% of the treatment series, in improving both the accuracy of localization of the target volume (48% of the patients) and the calculation of the dose distribution (31% of the patients) that its use is recommended during the radiotherapy planning of pelvic tumors.