Standard maintenance therapy versus local consolidative radiation therapy and standard maintenance therapy in 1-5 sites of oligometastatic non-small cell lung cancer: a study protocol of phase III randomised controlled trial

Introduction Two-phase II randomised studies have shown a significant benefit of local consolidation therapy in oligometastatic non-small cell lung cancer (NSCLC). This phase III randomised controlled trial (RCT) will evaluate the efficacy of local consolidation radiation therapy (RT) in oligometastases (OM) NSCLC after completion of initial systemic therapy. Methods and analysis This is a single-centre phase III RCT of OM NSCLC patients. One hundred and ninety patients will undergo 1:1 randomisation to either standard maintenance therapy (control arm) or local consolidation RT and standard maintenance therapy (experimental arm). Patients will be stratified into the number of OM sites (1-2 vs 3-5), nodal metastases (N0-N1 vs N2-N3) and presence or absence of brain metastases. Stereotactic body radiation therapy to all the oligometastatic sites and definitive RT to primary disease will be given in the experimental arm. The primary endpoint is overall survival and secondary endpoints include progression-free survival, local control of OM sites, new distant metastases free survival, objective response rate, toxicity and quality of life. Translation endpoint include circulating tumour cells and radiomics using texture analysis. Ethics and dissemination All patients will be provided with a written informed consent form which needs to be signed before randomisation. The study is approved by the institutional ethics committee-II (project number 3445) and registered with Clinical Trials Registry-India, dated 21 April 2020.