Abstract

Purpose: Three radiation therapy techniques for breast are common, namely three-dimensional conformal radiotherapy (3D-CRT), Field-in-Field (FIF), and Intensity-Modulated Radiotherapy (IMRT). The purpose of this study was to determine and compare dosimetric parameters of three different treatment planning planning types; 3D-CRT, FIF, and IMRT in target and normal tissues after breast-conserving surgery. Methods: One hundred patients with left or right breast cancer cooperated in this study. They were divided into three categories (small, medium, and large size) based on breast volume. Three treatment planning techniques were carried out by planner for each patient in Prowess® 5.2 Treatment Planning System. The dosimetric parameters were obtained from dose-volume histograms using the CERR software (MATLAB Company, Washington, USA), which runs as an add-on in MATLAB software. Results: 3D-CRT technique with the highest value of D max creates more hot spots than the other techniques in the tumor region (P = 0.013). IMRT and FIF showed the best uniformity compared to 3D-CRT in all groups with respect to the values of the parameters D 98 and D 2. IMRT provided the best coverage in the tumor compared to other methods (P < 0.001). 3D-CRT technique yielded a high volume receiving ≥107 of the prescription dose (P < 0.001). Among the three methods, the FIF method results in a lower dose to the lung for treatment based on the V 5 and V 20 parameters (P < 0.001). Homogeneity index for IMRT was better than FIF, as well as, conformity index (CI) for IMRT and FIF was better than 3D-CRT. Conclusion: IMRT and FIF plans offered excellent target coverage and uniformity, whereas FIF had better protection of healthy tissues. Thus FIF method is an efficient method to improve the quality of treatment for breast cancer patients. © 2023 Wolters Kluwer Medknow Publications. All rights reserved.