Hypofraction Radiotherapy for Limited-Stage Small Cell Lung Cancer

Concurrent chemoradiotherapy is the standard modality for locally advanced small-cell lung cancer, which could achieve median overall survival of 25 mos. Conventional fractionation of 66Gy/33f and hyperfractionation of 45Gy/30f twice daily have been acknowledged as the two standard radiotherapy modalities according to CONVERT study. In 2021, a phase II trial demonstrated that 60Gy/40f twice daily was superior to the standard 45Gy/30f twice daily in light of overall survival (2y OS 74.2% vs. 39% p=0.0005), which to some extent implied that higher dose may confer better survival. Hypofractionated radiotherapy was another useful modality to increase biological effective dose with the advantage of short course and convenience. The effectiveness and safety of 60Gy/15f has been demonstrated in the treatment of locally advanced non-small cell lung cancer. Therefore, this trial is designed to explore the safety and primary efficacy of hypofraction radiotherapy for stage III locally advanced small cell lung cancer.