3-DIMENSIONAL TREATMENT PLANNING AND CONFORMAL RADIATION-THERAPY - PRELIMINARY EVALUATION

Preliminary clinical results are presented for 209 patients with cance r who had treatment planned on our three-dimensional radiation treatme nt planning (3-D RTP) system and were treated with external beam confo rmal radiation therapy. Average times (min) for CT volumetric simulati on were: 74 without or 84 with contrast material; 36 for contouring of tumor/target volume and 44 for normal anatomy; 78 for treatment plann ing; 53 for plan evaluation/optimization; and 58 for verification simu lation. Average time of daily treatment sessions with 3-D conformal th erapy or standard techniques was comparable for brain, head and neck, thoracic, and hepatobiliary tumors(11.8-14 min and 11.5-12.1, respecti vely). For prostate cancer patients treated with 3-D conformal techniq ue and Cerrobend blocks, mean treatment time was 19 min; with multilea f collimation it was 14 min and with bilateral are rotation, 9.8 min. Acute toxicity was comparable to or lower than with standard technique s. Sophisticated 3-D RTP and conformal irradiation can be performed in a significant number of patients at a reasonable cost. Further effort s, including dose-escalation studies, are necessary to develop more ve rsatile and efficient 3-D RTP systems and to enhance the cost benefit of this technology in treatment of patients with cancer.