Ablative Radiotherapy for Ultracentral Primary Non-Small Cell Lung Cancer: Dosimetric and Anatomic Predictors of Outcomes and Toxicities

Ultracentral (UC) lung cancers have been associated with worse outcomes and higher toxicity rates after treatment with ablative radiation therapy (RT). Definitions of UC include 1) gross tumor volume (GTV) directly abutting the central airway, 2) planning tumor volume (PTV) overlapping the trachea or mainstem bronchi, or 3) GTV within 1 cm of the proximal bronchial tree (PBT). We sought to associate dosimetric and anatomic factors with oncologic...