Tangential beam intensity modulated radiotherapy versus tangential beam three-dimensional conformal radiotherapy in carcinoma breast: A dosimetric comparison and clinical correlation

Abstract

Purpose: This study evaluates the dose distribution of tangential beam intensity modulated radiotherapy (IMRT) compared to tangential beam three-dimensional conformal radiotherapy (3D-CRT) in carcinoma breast. Methods: Tangential beam IMRT and tangential beam 3D-CRT plans were generated in 54 postoperative breast cancer patients. Planning target volume (PTV) definition of chest wall and intact breast was done according to Breast Cancer Atlas for Radiation Therapy Oncology Group. The prescribed dose was 50 Gy in 25 fractions. Dose volume histograms was evaluated for PTV and organs at risk, parameters of the dose distribution were compared for 3D-CRT and IMRT using Wilcoxon Matched pairs test. The dosages were clinically correlated with normal tissue reactions. Results: No difference in the conformity index but IMRT improves the homogeneity index significantly (P Conclusion: Tangential beam IMRT in breast cancer offers the potential to significantly reduce the dose-volume of the ipsilateral lung and dose volume of the heart which will translate into decrease in risk of cardiac and lung toxicity and also decreased second cancer risk. IMRT definitely decreases the acute skin reactions in all patients.