Certainty versus practicality: when is histologic proof needed prior to stereotactic ablative radiotherapy for solitary pulmonary nodules?

Stereotactic ablative radiotherapy (SABR) is a radiotherapy technique for treating early-stage non-small cell lung cancer (NSCLC), and is characterized by high dose per fraction, few fractions, and image-guided precision. Multiple studies have consistently demonstrated high rates of local control and a low incidence of serious adverse events, making it an attractive option for patients who are medically unfit for surgery. Although a biopsy is recommended for confirmation of the diagnosis prior to treatment, it is not without its risks. Herein we review the necessity of a biopsy prior to SABR for a solitary pulmonary nodule (SPN) suspicious for early-stage NSCLC. We examine malignancy prediction tools for assessing SPNs and scenarios in which forgoing a biopsy could be reasonable.