THE IMPACT OF 3-D RADIOTHERAPY PLANNING AFTER A PNEUMONECTOMY COMPARED TO A CONVENTIONAL TREATMENT SET-UP

Three-dimensional radiotherapy planning (3-D RTP) is becoming more ava ilable in clinical practice, although so far there is little data show ing its clinical advantage. The goal of this study was to compare 3-D RTP and dose delivery with conventional treatment planning in pneumone cted lung cancer patients, receiving postoperative irradiation. Adjuva nt radiotherapy in 20 pneumonected patients was planned with a 3-D sys tem and patients were irradiated according to this plan. The resulting dose distribution was compared with the combination of a simulator an d 2-D planned treatment to the same target volume. Dose volume histogr ams of the target, the lung and the heart of both treatment plans were analysed. A biophysical model was added to estimate the differences i n the biological effect. 3-D RTP significantly reduced the mean dose t o the lung in 14/20 patients and to the heart in 20/20 patients. The m ean dose delivered to the target was equal in both planning methods. T he early clinical results do not differ from published results in post operatively treated lung cancer patients.