Department of Clinical Oncology, Velindre Cancer Centre, Velindre Road, Whitchurch, Cardiff, CF14 2TL, UK.
Department of Clinical Oncology, Addenbrookes' Hospital, Box 193, Cambridge, CB2 0QQ, UK.
Radiat Oncol. 2019 Apr 3;14(1):57. doi: 10.1186/s13014-019-1262-8.
Advanced pelvic radiotherapy techniques aim to reduce late bowel toxicity which can severely impact the lives of pelvic cancer survivors. Although advanced techniques have been largely adopted worldwide, to achieve their aim, knowledge of which dose-volume parameters of which components of bowel predict late bowel toxicity is crucial to make best use of these techniques. The rectum is an extensively studied organ at risk (OAR), and dose-volume predictors of late toxicity for the rectum are established. However, for other components of bowel, there is a significant paucity of knowledge. The Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) reviews recommend dose-volume constraints for acute bowel toxicity for peritoneal cavity and bowel loops, although no constraints are recommended for late toxicity, despite its relevance to our increasing number of survivors. This systematic review aims to examine the published literature to seek dose-volume predictors and constraints of late bowel toxicity for OARs (apart from the rectum) for use in clinical practice.
A systematic literature search was performed using Medline, Embase, Cochrane Library, Web of Science, Cinahl and Pubmed. Studies were screened and included according to specific pre-defined criteria. Included studies were assessed for quality against QUANTEC-defined assessment criteria.
101 studies were screened to find 30 relevant studies. Eight studies related to whole bowel, 11 to small bowel, and 21 to large bowel (including 16 of the anal canal). The anal canal is an important OAR for the development of late toxicity, and we recommend an anal canal Dmean <40Gy as a constraint to reduce late incontinence. For other components of bowel (sigmoid, large bowel, intestinal cavity, bowel loops), although individual studies found statistically significant parameters and constraints these findings were not corroborated in other studies.
The anal canal is an important OAR for the development of late bowel toxicity symptoms. Further validation of the constraints found for other components of bowel is needed. Studies that were more conclusive included those with patient-reported data, where individual symptom scores were assessed rather than an overall score, and those that followed statistical and endpoint criteria as defined by QUANTEC.
先进的盆腔放疗技术旨在降低晚期肠道毒性，这会严重影响盆腔癌症幸存者的生活。尽管先进技术已在全球范围内广泛采用，但为了实现这一目标，了解哪些肠道成分的剂量-体积参数可预测晚期肠道毒性，对于充分利用这些技术至关重要。直肠是一个广泛研究的危及器官（OAR），并且已经建立了预测直肠晚期毒性的剂量-体积预测因子。但是，对于肠道的其他成分，我们的了解还非常有限。定量分析正常组织在临床中的效应（QUANTEC）综述建议为腹腔和肠袢的急性肠道毒性设定剂量-体积限制，尽管没有为晚期毒性推荐限制，尽管它与我们越来越多的幸存者相关。本系统综述旨在检查已发表的文献，以寻找除直肠以外的 OAR （包括直肠）的晚期肠道毒性的剂量-体积预测因子和限制因素，以用于临床实践。
使用 Medline、Embase、Cochrane 图书馆、Web of Science、Cinahl 和 Pubmed 进行系统文献检索。根据特定的预定义标准筛选和纳入研究。根据 QUANTEC 定义的评估标准对纳入的研究进行质量评估。
共筛选了 101 项研究，找到了 30 项相关研究。其中 8 项研究与全肠相关，11 项研究与小肠相关，21 项研究与大肠（包括 16 项与肛门直肠相关）相关。肛门直肠是发生晚期毒性的重要 OAR，我们建议将肛门直肠 Dmean <40Gy 作为限制，以减少晚期失禁的发生。对于肠道的其他成分（乙状结肠、大肠、肠腔、肠袢），尽管个别研究发现了具有统计学意义的参数和限制，但其他研究并未证实这些发现。
肛门直肠是发生晚期肠道毒性症状的重要 OAR。需要进一步验证其他肠道成分的发现限制。更具结论性的研究包括那些具有患者报告数据的研究，其中评估了个体症状评分，而不是总体评分，以及那些遵循 QUANTEC 定义的统计和终点标准的研究。
