Reirradiation of recurrent node-positive non-small cell lung cancer after previous stereotactic radiotherapy for stage I disease

Background Practice guidelines have been developed for early-stage and locally advanced non-small cell lung cancer (NSCLC). However, many common clinical scenarios still require individualized decision making. This is true for locoregional relapse after initial stereotactic radiotherapy (stereotactic body radiation therapy or stereotactic ablative radiotherapy; SBRT or SABR), an increasingly utilized curative treatment option for stage I NSCLC. Methods A consortium of expert radiation oncologists was established with the aim of providing treatment recommendations. In this scenario, a case was distributed to six radiation oncologists who provided their institutions' treatment recommendations. In this case, a patient developed local and mediastinal relapse after SABR (45Gy, 3 fractions), comparable to the tumor burden in de novo stage IIIA NSCLC. Treatment recommendations were tabulated and a consensus conclusion was developed. Results Three institutions recommended evaluation for surgery. If the patient was not a surgical candidate, and/or refused surgery, definitive chemoradiation was recommended, including retreating the primary to full dose. European participants were more in favor of a non-surgical approach. None of the participants were reluctant to prescribe reirradiation, but two institutions prescribed doses lower than 60Gy. Platinum-based doublets together with intensity-modulated radiotherapy were preferred. Conclusion The institutional recommendations reflect the questions and uncertainties discussed in current stage III guidelines. All institutions agreed that previous SABR is not a contraindication for salvage chemoradiation. In the absence of high-quality prospective trials for recurrent NSCLC, all treatment options recommended in current guidelines for stage III disease can be considered in clinical scenarios such as this.