A Hybrid Conformal Planning Technique with Solitary Dynamic Portal for Postmastectomy Radiotherapy with Regional Nodes

摘要

Purpose: This study focuses on incorporation of a solitary dynamic portal (SDP) in conformal planning for postmastectomy radiotherapy (PMRT) with nodal regions with an intention to overcome the treatment planning limitations imposed by conventional techniques. Materials and Methods: Twenty-four patients who underwent surgical mastectomy followed by PMRT were included in this study. Initially, a treatment plan comprising tangential beams fitted to beam's-eye-view (BEV) of chest wall (CW) and a direct anterior field fitted to BEV of nodal region, both sharing a single isocenter was generated using Eclipse treatment planning system. Multiple field-in-fields with optimum beam weights (5% per field) were added primarily from the medial tangent, fitted to BEV of entire target volume, and finally converted into a dynamic portal. Dosimetric analysis for the treatment plans and fluence verification for the dynamic portals were performed. Results and Discussion: Conformal plans with SDP showed excellent dose coverage (V_95%