Abstract

Highly focused, accurate and image-guided radiation delivery to very potent dose can be safely delivered using the techniques and technologies employed with stereotactic ablative radiotherapy (SABR). SABR is fundamentally different from conventionally fractionated radiotherapy in its approach, conduct, techniques, and biology. Trials in early stage lung cancer have demonstrated targeted tumour control similar to surgery with tolerance in even non-surgical patients.  In these clinical models, the treatment has been optimised with impressive clinical results that have justified making SABR a standard option for several patient populations. Initial use in advanced and metastatic cancer have centered primarily around oligometastatic presentations similar to surgical indications. However, more recent clinical trials have identified patient populations with even more extensive dissemination that might benefit. Considering the difficulty in controlling gross disease with systemic therapy, a non-invasive local therapy could allow longer progression free intervals and, perhaps, improved survival. SABR integrates seamlessly with systemic therapies and could prove to be synergistic. Within this clinical model of metastatic patients in need of better therapy, SABR is being tested hoping to allow improved tumour control while maintaining high levels of quality life.