This will be an open-label, single-arm, phase II study comparing dose escalated adaptive thoracic radiotherapy to historical control of standard of care single planned radiotherapy field for entire treatment course in patients with newly diagnosed limited stage small cell lung cancer eligible for concurrent chemoradiation with platinum doublet based chemotherapy, or extensive stage small cell lung cancer patients with radiation-targetable intra-thoracic disease and none or limited extra-thoracic disease that are eligible for up-front platinum doublet chemotherapy and are fit to receive concurrent radiotherapy.~The adaptive dose-escalated radiotherapy treatment plan will be delivered in three sequential phases with two scheduled replans during the treatment along with scaled dose limits for organs-at-risk. Up to 70 Gy in 35 fractions can be delivered to the disease without overdosing organs-at-risk, and treatment will last 5 - 7 weeks. Scheduled CT simulations for the replans will be at fraction 5 and fraction 10 to account for the expected rapidly shrinking tumour volumes. Participants will be followed for 24 months to investigate local failure rate, medium progression-free survival, overall survival, acute radiation toxicity, and late radiation toxicity. Follow-up after the study will be as per standard-of-care for secondary endpoints.
The purpose of this study is to find out what effects of using adaptive radiotherapy to deliver chest radiation has on the ability to control lung cancer and side effects.