MO-F-BRCD-01: Stereotactic Body Radiation Therapy: Updates on Clinical, Biological, and Physics/QA:SBRT (Part 1): Biological and Clinical Updates.

Stereotactic Body Radiation Therapy (SBRT) is an important form of cancer therapy with increasingly broad application across a spectrum of tumor types in primary and metastatic settings. In this presentation the radiation biology, clinical experience from various trials, and cautionary updates on normal tissue tolerances will be presented. The effective radiobiology of SBRT and hypofractionated courses of therapy has become more evident with the increasing reports of retrospective clinical outcomes and prospective clinical trial results. Current open multi-institutional national cooperative trials will be reviewed. Accumulating clinical experiences are yielding new insights into practical aspects of tumor and normal tissue responses to high dose per fraction treatment. Indeed, SBRT has produced profound tumoricidal and ablative effects, however there is potential for grave toxicity and this demands that clinicians be knowledgeable regarding normal tissue tolerances for various hypofractionated courses. As a final note, the technology associated with SBRT has evolved remarkably in the last decade, and procedures that originally required hours to plan, with cumbersome quality assurance methods, arduous set-up times, and long protracted deliveries can now be performed in ever shorter time periods. Given these technology improvements and recognizing the great palliative potential of hypofractionated radiation therapy to relieve cancer symptoms quickly and efficiently, a new strategy to deliver SBRT in a single session called STAT RAD is presented for discussion.