Hippocampus sparing volumetric modulated arc therapy in patients with loco-regionally advanced oropharyngeal cancer

Seung Won Seol; Brian H Lee; Timothy L Sita; Jay Ram Devineni; Tim J Kruser; Sean Sachdev; Michelle Gentile; Irene Helenowski; Bharat B Mittal

doi:10.1016/j.phro.2022.09.008

Hippocampus sparing volumetric modulated arc therapy in patients with loco-regionally advanced oropharyngeal cancer

Phys Imaging Radiat Oncol. 2022 Sep 24:24:71-75. doi: 10.1016/j.phro.2022.09.008. eCollection 2022 Oct.

Authors

Seung Won Seol¹, Brian H Lee¹, Timothy L Sita¹, Jay Ram Devineni¹, Tim J Kruser¹, Sean Sachdev¹, Michelle Gentile¹, Irene Helenowski², Bharat B Mittal¹

Affiliations

¹ Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
² Department of Preventive Medicine, Northwestern University Biostatistics Division, Chicago, IL, USA.

Abstract

This study aimed to assess the incidental radiation exposure of the hippocampus (HC) in locoregionally-advanced oropharyngeal cancer patients undergoing volumetric modulated arc therapy and the feasibility of HC-sparing plan optimization. The initial plans were generated without dose-volume constraints to the HC and were compared with the HC-sparing plans. The incidental D_mean_median doses to the bilateral, ipsilateral and contralateral HC were 2.9, 3.1, and 2.5 Gy in the initial plans and 1.4, 1.6, and 1.3 Gy with HC-sparing. It was feasible to reduce the HC dose with HC-sparing plan optimization without compromising target coverage and/or dose constraints to other OARs.

Keywords: Hippocampus; Hippocampus-sparing; IMRT; Oropharyngeal; Plan optimization.