Using the CT-scanner to explore and circumnavigate current inadequacies in radiotherapy planning.

Successful radiotherapy practice depends on the irradiation of tumours such that their destruction follows without unacceptable damage of the surrounding normal tissues. Until recently the accurate acquisition of data concerning the tumour anatomy lagged behind other developments in radiotherapy. Since the arrival of the CT scanner, these anatomical data can be displayed ideally for transmission into a computerised treatment planning system. The CT scan information concerning tumour location, irradiation volume and dosimetry was compared with results obtained using traditional planning methods. In this series, CT scanning appears to be useful in 65 of the 126 patients (52%).