Schaldemose Ellen Lund, Madsen Christine Vestergaard, Zedan Ahmed Hussein, Berg Martin, Nissen Henrik Dahl, Andersen Terje, Mortensen Bjarke, Fokdal Lars Ulrik
Department of Oncology, Vejle Hospital, University Hospital of Southern Denmark, Vejle, Denmark.
Department of Oncology, Vejle Hospital.
Acta Oncol. 2025 May 8;64:644-653. doi: 10.2340/1651-226X.2025.42551.
Rectal bleeding is a well-known adverse event following pelvic external beam radiotherapy (EBRT) for prostate cancer. This study investigates risk factors for rectal bleeding and validate our current rectal dose constraints in a real-world setting.
This prospective study includes 248 prostate cancer patients who received EBRT between 2017-2022. EBRT consisted of 56 Gy/39 fractions to the prostate, elective lymph nodes, and seminal vesicles with an integrated boost of 78 Gy to the prostate alone (≤T3a) or to the prostate and seminal vesicles (T3b). Rectal dose constraints were V50 Gy ≤50%, V70 Gy ≤20%, and V74 Gy ≤12%. Rectal bleeding was recorded at baseline and regularly duringfollow-up and included staff reported morbidity and patient reported outcome measures. Risk factors were evaluated in multivariate cox regression analysis.
Median follow-up was 18 months (range 1-61 months). Sixteen percent (CI:11%;22%) of patients reported rectal bleeding as "rarely", 4%(CI:2%;8%) "about half the time", 0% "usually", and 2%(CI:0%;4%) "always". Five percent reported rectal bleeding as bothersome. It was possible to comply with current rectal dose constraint (V74 Gy ≤12%) in 99.6% of all patients. Body mass index (BMI) (BMI:25-29.9, HR:0.54(CI:0.30;0.98), p=.044 or BMI>29.9, HR:0.40(CI:0.20;0.79), p=0.008)) were predictors for rectal bleeding.
Patient-reported rectal bleeding is common after prostate cancer radiotherapy. High BMI was a protective factor against rectal bleeding. No correlation was observed between rectal dose-volume constraints and the occurrence of rectal bleeding, suggesting that a rectal high-dose constraint of V74 Gy ≤12% is an adequate threshold to minimize patient-reported rectal bleeding.
直肠出血是前列腺癌盆腔外照射放疗（EBRT）后一种众所周知的不良事件。本研究调查直肠出血的危险因素，并在实际临床环境中验证我们目前的直肠剂量限制。
这项前瞻性研究纳入了2017年至2022年间接受EBRT的248例前列腺癌患者。EBRT包括对前列腺、选择性淋巴结和精囊给予56 Gy/39次分割照射，对前列腺单独（≤T3a）或前列腺与精囊（T3b）给予78 Gy的同步推量照射。直肠剂量限制为V50 Gy≤50%，V70 Gy≤20%，V74 Gy≤12%。在基线时以及随访期间定期记录直肠出血情况，包括工作人员报告的发病率和患者报告的结局指标。在多因素Cox回归分析中评估危险因素。
中位随访时间为18个月（范围1 - 61个月）。16%（CI：11%；22%）的患者报告直肠出血为“很少”，4%（CI：2%；8%）为“约一半时间”，0%为“通常”，2%（CI：0%；4%）为“总是”。5%的患者报告直肠出血令人困扰。在所有患者中，99.6%能够遵守目前的直肠剂量限制（V74 Gy≤12%）。体重指数（BMI）（BMI：25 - 29.9，HR：0.54（CI：0.30；0.98），p = 0.044；或BMI>29.9，HR：0.40（CI：0.20；0.79），p = 0.008））是直肠出血的预测因素。
患者报告的直肠出血在前列腺癌放疗后很常见。高BMI是预防直肠出血的保护因素。未观察到直肠剂量 - 体积限制与直肠出血的发生之间存在相关性，这表明V74 Gy≤12%的直肠高剂量限制是将患者报告的直肠出血降至最低的合适阈值。
