Differentiating Radiation Changes from Local Recurrence after SBRT for Lung Cancer: The Need for Better Decision Guidelines

Abstract

Radiographic lung changes and fibrosis are near ubiquitous observations on CT imaging following the treatment of non-small cell lung cancer with stereotactic body radiation therapy (SBRT). The distinction between these radiographic changes and a local cancer recurrence in a timely and accurate fashion is critical for successful salvage therapy as well as to avoid potentially detrimental overtreatment. Nonetheless, an adequate, widely accepted and validated approach for post-treatment surveillance and identification of recurrences is unavailable. This article relates a case wherein the failure of close follow up imaging and uncertainty in the interpretation of imaging resulted in overtreatment. It also identifies some of the shortcomings in the current attempts to develop an appropriate post-SBRT follow up schedule, examines the physiological and radiographic post-SBRT radiation changes and reviews the pertinent literature.