Clinical outcomes of pelvic bone marrow sparing radiotherapy for cervical cancer: A systematic review and meta-analysis of randomised controlled trials

Background Concurrent chemoradiotherapy (CRT) is the standard treatment for locally advanced cervical cancer. We investigated how additional bone marrow sparing (BMS) affects the clinical outcomes. Methods We queried MEDLINE, EMBASE, Web of Science, Google Scholar, Sinomed, CNKI, and Wanfang databases for articles published in English or Chinese between 2010/01/01 and 2023/10/31. Full-text manuscripts of prospective, randomised trials on BMS in cervical cancer patients treated with definitive or postoperative CRT were included. Risk of bias (RoB) was assessed using Cochrane Collaboration’s RoB tool. Random-effect models were used for the meta-analysis. Results A total of 17 trials encompassing 1297 patients were included. The majority were single-centre trials (n = 1268) performed in China (n = 1128). Most trials used CT-based anatomical BMS (n = 1076). There was a comparable representation of trials in definitive (n = 655) and postoperative (n = 582) setting, and the remaining trials included both.Twelve studies reported data on G ≥ 3 (n = 782) and G ≥ 2 (n = 754) haematologic adverse events. Both G ≥ 3 (OR 0.39; 95 %CI 0.28–0.55; p < 0.001) and G ≥ 2 (OR 0.29; 95 %CI 0.18–0.46; p < 0.001) toxicity were significantly lowered, favouring BMS. Seven studies (n = 635) reported data on chemotherapy interruptions, defined as receiving less than five cycles of cisplatin, which were significantly less frequent in patients treated with BMS (OR 0.44; 95 %CI 0.24–0.81; p = 0.016). There was no evidence of increased gastrointestinal or genitourinary toxicity.There were no signs of significant heterogeneity. Four studies were assessed as high RoB; sensitivity analyses excluding these provided comparable results for main outcomes. The main limitations include heterogeneity in BMS methodology between studies, low representation of populations most affected by cervical cancer, and insufficient data to assess survival outcomes. Conclusions The addition of BMS to definitive CRT in cervical cancer patients decreases hematologic toxicity and the frequency of interruptions in concurrent chemotherapy. However, data are insufficient to verify the impact on survival and disease control.