Assessing the impact of elective regional radiotherapy on survival

PURPOSE Elective regional irradiation (ERI) of sites of likely tumor spread has bee n common radiation oncology practice for decades. It is based, in part, on the assumption that cancer often spreads in an orderly fashion and that an improvement in regional control will increase survival. METHOD The clinical data regarding the impact of ERI on local-regional control vs survival are reviewed for a variety of tumor sites. RESULTS Improvements in survival with ERI have been reported in some clinical situations. For most , however, survival improvements have been difficult to realize. In most cl inical situations, the realistic improvement in survival that is achievable with ERI is small and would be difficult to document in reasonably sized c linical trials. DISCUSSION The dose-response relationship for the impact of ERI on survival is discuss ed. A hypothesis suggesting that a reduction in the dose of ERI may improve the therapeutic ratio of ERI (with respect to its impact on survival) is p resented.