Experience of the Hybrid technique for breast cancer planning in an oncology care center in Lima-Peru

Abstract

Objective: To investigate, describe and evaluate the dosimetric parameters of the hybrid technique as a combination of the 3D Irregular Surface Compensator (3D-ISC) technique and modulated volumetric arc therapy (VMAT) for breast cancer planning. Methods: The study involved planning a patient with left breast cancer. Planning was carried out with 3D-ISC, VMAT and Hybrid techniques. The 3 techniques were compared with respect to the target volume (PTV), coverage, gradient and protection of organs at risk (OARs). The Eclipse version 13.6 planning system was used and the prescription of the dose obeyed the hypofractionated scheme of 40.05Gy in 15 sessions (267 cGy per fraction) followed by a 13.35Gy boost in 5 sessions. Results: The tangential field technique was the one with the lowest dose values delivered to healthy organs. However, with respect to the gradient, the VMAT technique was better. The Hybrid technique was the balance between the 3D-ISC and VMAT technique because after the evaluation of dosimetric parameters for both the OARs and the PTV coverage, values were found within the limits allowed according to the RTOG. Conclusion: The hybrid 3D-ISC and VMAT technique can be considered as a viable option for breast planning, achieving better control in OARs without losing priority over PTV coverage in addition to obtaining a good plan quality.