Dosimetric Comparison of Tangential Volumetric Arc Therapy and Half Beam Volumetric Modulated Arc Therapy Planning Technique for Carcinoma of the Breast

Introduction: This study aims to compare tangential volumetric modulated arc therapy with half beam volumetric modulated arc therapy in the treatment of cancer in the left and right breasts. Material and Methods: Twenty patients (10 with left and 10 with right breast cancer) were planned with Tangential Volumetric Modulated Arc Therapy (tVMAT) and Half Beam Volumetric Modulated Arc Therapy (HVMAT) techniques for prescribed dose of 42.56Gy over 16 fractions with 6MV photon. The tVMAT technique limit the radiation to non-target areas. Dosimetric evaluations were performed for planning target volume (PTV), ipsilateral lung, heart, and contralateral breast with analysis via Repeated Measures ANOVA with a significance level of 5%. Results: tVMAT achieved superior target coverage and dose homogeneity compared to HVMAT. For left breast cancer, HVMAT reduced ipsilateral lung doses but increased contralateral breast doses. Heart doses remained similar in both techniques. For right breast cancer, tVMAT provided higher target coverage and reduced doses across critical parameters. Conclusion: tVMAT demonstrates strong potential as an advanced radiotherapy technique for breast cancer, improving dose control to the ipsilateral lung and heart while minimizing dose spread to the contralateral side, making it a promising alternative to conventional VMAT for enhanced precision in breast cancer treatment.