Peng LC, et al. - The prognostic influence of perineural invasion (PNI) for prostate cancer patients who underwent external beam radiotherapy (EBRT) with and without androgen deprivation therapy (ADT) was reviewed. PNI was an independently significant predictor, particularly for patients with NCCN low-risk disease. For select low-risk patients with PNI, supplementing EBRT with ADT could be beneficial.