The Future of Radiosurgery and SBRT: SRS and SBRT Complications and Management

Stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) have revolutionized how we treat malignant and benign tumors and disorders. Technological advancements enabling highly precise delivery of radiation with sharp dose fall off outside the target have accelerated the adoption of SRS and SBRT. Despite the high conformality of SRS and SBRT plans, predicting the actual risk of toxicities with these modalities is challenging because radiobiological impact of delivering high doses per fraction (≥5 Gy) on various normal tissue remains incompletely understood. Therefore, optimizing the safety profile of SBRT and SRS is contingent upon improved insight into the true dose tolerances of organs-at-risk (OAR) at high doses per fraction. The OAR constraints included in the Timmerman tables, which is the most commonly used reference for dose constraints during SBRT planning, are not clinically validated. The Hypofractionated Treatment Effects in the Clinic (HyTEC) initiative represents the latest effort to investigate the dose tolerances of OARs with SRS and SBRT through normal tissue complication probability (NTCP) modeling analysis. While improvements in radiation planning aim to reduce the risk of developing severe late toxicities after SRS and SBRT, further research is also needed to establish effective and standardized treatment algorithms for these toxicities.