Incidental Radiation Dose to the Esophagus and Trachea Using Conventional Supraclavicular Fields: A Retrospective Dosimetric Study

Abstract

with similar, but modestly improved sparing of most OARs: ipsilateral lung V20 7.3% (RTOG PBS) vs. 5.3% (ESTRO PBS) and 24% (RTOG VMAT) vs. 20% (ESTRO VMAT), mean heart dose 0.49 GyRBE (RTOG PBS) vs. 0.51 GyRBE (ESTRO PBS) and 4.95 Gy (RTOG VMAT) vs. 4.82 Gy (ESTRO VMAT). Notably, contralateral lung doses with VMAT were higher using the updated ESTRO-ACROP guidelines compared to RTOG guidelines with a mean V10 of 19.6%. Conclusion: PMRT with reconstruction utilizing the updated ESTRO-ACROP consensus contouring guidelines is feasible with both VMAT and PBS proton therapy. Treatment plans utilizing the updated contouring guidelines provided equivalent target coverage compared to conventional guidelines, while modestly further sparing cardiopulmonary structures. Care must be taken with new contouring guidelines when utilizing VMAT to minimize undue contralateral lung exposure.