Conclusions: Patients with elevated pre-SABR non-target lung FDG-PET uptake are at increased risk of symptomatic RP after lung SABR.

Conclusions: We highlight Random Forest as an accurate machine learning method to identify known and new predictors of symptomatic RP.

Patients with relapsed or refractory lymphoma who received salvage chemotherapy and hematopoietic stem cell transplantation were at higher risk for symptomatic RP.