COMPARATIVE ANALYSIS OF THE RADIATION EXPOSURE ON THE TARGET AND CRITICAL ORGANS WITH 2D AND 3D PLANNING OF RADIATION THERAPY FOR LUNG CANCER

Background and purpose. The purpose of this investigation was to evaluate feasibility, safety and efficacy of radiotherapy for inoperable non-small-cell lung cancer (NSCLC). Various radiotherapy planning methods have been proposed to decrease normal tissue toxicity. We compared 2D-RT with 3D-RT for NSCLC. Parameters assessed included dose to PTV and organ-at-risk (OAR), multiple conformity and homogeneity indices. Material and methods. Initial and re-simulation CT images from 52 consecutive patients with IIB – IIIB NSCLC were used to quantify dosimetric differences between 2D and 3D conformal radiotherapy. Contouring was performed on both CTs, and plans (n=104 plans) and dose-volume histograms were generated. Results. All plans provided comparable PTV coverage. Compared with 2D-RT, 3D-RT significantly reduced the maximum dose to heart (p<0.01), spinal cord (p<0.01), whole lung (p<0.01), esophagus (p<0.02) – Wilcoxon test