背景:局部晚期直肠癌(LARC)的标准治疗包括新辅助放化疗,然后全直肠系膜切除术。文献中的不同数据显示,使用放疗剂量递增对肿瘤降低分期和病理完全缓解(pCR)率有益,然而,缺乏使用LARC创新技术(T3-4或N1-2)的剂量递增研究。
目的:分析使用创新的放疗技术对LARC新辅助放疗剂量递增的作用。
方法:2020年12月,我们对以下电子数据库进行了全面的文献检索:PubMed,WebofScience,Scopus和Cochrane图书馆。研究的限制期包括2009年1月至2020年12月发表的文章。通过标题和摘要进行筛选,以确定仅使用辐射剂量等效剂量2Gy分数(EQD2)≥54Gy和体积调制电弧疗法(VMAT)的研究,调强放射治疗或图像引导放射治疗(IGRT)技术。作者搜索总共产生了2287个结果,根据PRISMA集团(2009)的筛选过程,21种出版物符合选择标准,并被纳入审查。
结果:使用的主要放射治疗技术包括VMAT和IGRT模式。主要剂量处方为55Gy至高风险体积,45Gy作为预防体积,在25个部分中使用同时集成增强技术(42.85%)。平均pCR为28.2%,处方剂量与缓解率之间无相关性(P值≥0.5)。R0边缘和括约肌保存率分别为98.88%和76.03%,分别。经过35个月的平均随访,局部控制为92.29%。G3或更高的毒性为11.06%,剂量处方和毒性之间没有相关性。与其他组相比,接受EQD2剂量>58.9Gy和BED>70.7Gy的患者手术并发症发生率更高(P值=0.047)。
结论:使用创新技术的剂量递增新辅助放疗对于实现较高pCR率的LARC是安全的。EQD2剂量>58.9Gy与较高的手术并发症发生率相关。
BACKGROUND: The standard treatment of locally advanced rectal cancers (LARC) consists on neoadjuvant chemoradiotherapy followed by total mesorectal excision. Different data in literature showed a benefit on tumor downstaging and pathological complete response (pCR) rate using radiotherapy dose escalation, however there is shortage of studies regarding dose escalation using the innovative techniques for LARC (T3-4 or N1-2).
OBJECTIVE: To analyze the role of neoadjuvant radiotherapy dose escalation for LARC using innovative radiotherapy techniques.
METHODS: In December 2020, we conducted a comprehensive literature search of the following electronic databases: PubMed, Web of Science, Scopus and Cochrane library. The limit period of research included articles published from January 2009 to December 2020. Screening by title and abstract was carried out to identify only studies using radiation doses equivalent dose 2 Gy fraction (EQD2) ≥ 54 Gy and Volumetric Modulated Arc Therapy (VMAT), intensity-modulated radiotherapy or image-guided radiotherapy (IGRT) techniques. The authors\' searches generated a total of 2287 results and, according to PRISMA Group (2009) screening process, 21 publications fulfil selection criteria and were included for the
review.
RESULTS: The main radiotherapy technique used consisted in VMAT and IGRT modality. The mainly dose prescription was 55 Gy to high risk volume and 45 Gy as prophylactic volume in 25 fractions given with simultaneous integrated boosts technique (42.85%). The mean pCR was 28.2% with no correlation between dose prescribed and response rates (P value ≥ 0.5). The R0 margins and sphincter preservation rates were 98.88% and 76.03%, respectively. After a mean follow-up of 35 months local control was 92.29%. G3 or higher toxicity was 11.06% with no correlation between dose prescription and toxicities. Patients receiving EQD2 dose > 58.9 Gy and BED > 70.7 Gy had higher surgical complications rates compared to other group (P value = 0.047).
CONCLUSIONS: Dose escalation neoadjuvant radiotherapy using innovative techniques is safe for LARC achieving higher rates of pCR. EQD2 doses > 58.9 Gy is associated with higher rate of surgical complications.