Objectives: It remains unclear whether hypofractionated (Hypo) thoracic radiotherapy (TRT) is superior to hyperfractionated or conventionally fractionated (Con) TRT in limited-stage small-cell lung cancer. Methods: PubMed, EMBASE, Web of Science, and the Cochrane Library were searched for eligible studies until April 30, 2023. The outcomes of interest were overall survival (OS), and grade ?3 esophagitis and pneumonitis, reported as hazard ratios (HRs) or odds ratios (ORs) with their 95% confidence intervals (CIs). Results: A total of 23 studies with 7987 patients were identified. Hypo-TRT showed similar OS compared to Hyper-TRT (HR = 1.22, 95% CI: 0.80-1.86 in randomized controlled trials [RCTs] and HR = 1.12, 95% CI: 0.99-1.28 in retrospective studies) and better OS compared to Con-TRT (HR =0.83, 95% CI: 0.70-0.97). Hyper-TRT achieved longer OS compared to Con-TRT in retrospective studies (HR = 0.91, 95% CI: 0.84-0.99), but not in RCTs (HR = 0.90, 95% CI: 0.80-1.01). There were no significant differences in incidence of grade ?3 esophagitis or pneumonitis between the three schedules. Conclusion: Hyper-TRT (45 Gy) or Con-TRT (60-70 Gy) remains a standard schedule. Hypo-TRT (40-45 Gy) is likely to be an alternative regimen. Nevertheless, these findings need to be validated in large phase 3 RCTs. Keywords: Hypofractionated; hyperfractionated; meta-analysis; small cell lung cancer; thoracic radiotherapy
Corresponding Author: Jun Dang