Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.
Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.
Radiother Oncol. 2023 Jan;178:109429. doi: 10.1016/j.radonc.2022.11.018. Epub 2022 Nov 28.
This study investigates the impact of dosimetric parameters on acute and late toxicity for patients with anal squamous cell carcinoma (SCC) treated with image-guided intensity modulated radiation therapy (IG-IMRT) and concurrent chemotherapy.
Patients were enrolled in an observational cohort study between 2008 and 2013 (median follow-up 3.4 years). They were treated with standardized target and organ-at-risk (OAR) contouring, planning, and IG-IMRT. Radiotherapy dose, based on clinicopathologic features, ranged from 45 Gy to 63 Gy to gross targets and 27 Gy to 36 Gy to elective targets. Chemotherapy was concurrent 5-fluorouracil and mitomycin C (weeks 1&5). Toxicity was prospectively graded using NCI CTCAE v.3 and RTOG scales. Logistic regression was used to assess the association between dose/volume parameters (e.g small bowel V5) and corresponding grade 2 + and 3+ (G2+/3 + ) toxicities (e.g. diarrhea).
In total, 87 and 79 patients were included in the acute and late toxicity analyses, respectively. The most common acute G2 + toxicities were skin (dermatitis in 87 % [inguino-genital skin], 91 % [perianal skin]) and hematologic in 58 %. G2 + late anal toxicity (sphincter dysfunction), gastrointestinal toxicity, and skin toxicity were respectively experienced by 49 %, 38 %, and 44 % of patients. Statistically significant associations were observed between: G2 + acute diarrhea and small bowel V35; G2 + acute genitourinary toxicity and bladder D; G2 + inguino-genital skin toxicity and anterior skin V35; G2 + perianal skin toxicity and posterior skin V15; G2 + anemia and lower pelvis bone V45. D0.5 cc was significantly predictive of late toxicity (G2 + anal dysfunction, intestinal toxicity, and inguino-genital/perianal dermatitis). Maximum skin toxicity grade was significantly correlated with the requirement for a treatment break.
Statistically significant dose-volume parameters were identified and may be used to offer individualized risk prediction and to inform treatment planning. Additional validation of the results is required.
本研究旨在探讨接受图像引导调强放疗（IG-IMRT）联合同期化疗的肛门鳞癌（SCC）患者的剂量学参数对急性和迟发性毒性的影响。
2008 年至 2013 年间，患者入组一项观察性队列研究（中位随访 3.4 年）。采用标准化的靶区和危及器官（OAR）勾画、计划和 IG-IMRT 进行治疗。根据临床病理特征，放疗剂量范围为 45Gy 至 63Gy 用于大体肿瘤靶区（GTV），27Gy 至 36Gy 用于选择性肿瘤靶区（CTV）。同期化疗方案为氟尿嘧啶和丝裂霉素 C（第 1 周和第 5 周）。采用 NCI CTCAE v.3 和 RTOG 量表前瞻性评估毒性。采用逻辑回归评估剂量/体积参数（如小肠 V5）与相应的 2+级和 3+级（G2+/3+）毒性（如腹泻）之间的相关性。
共纳入 87 例和 79 例患者分别进行急性和迟发性毒性分析。最常见的急性 2+级毒性为皮肤（皮炎，会阴部皮肤为 87%[腹股沟皮肤]，肛周皮肤为 91%）和血液学毒性（58%）。49%、38%和 44%的患者分别经历了 2+级晚期肛门毒性（肛门括约肌功能障碍）、胃肠道毒性和皮肤毒性。有统计学意义的相关性观察结果如下：急性腹泻 2+级与小肠 V35 相关；急性泌尿生殖毒性 2+级与膀胱 D 相关；急性腹股沟-会阴部皮肤毒性 2+级与前侧皮肤 V35 相关；急性肛周皮肤毒性 2+级与后侧皮肤 V15 相关；贫血 2+级与骨盆下部骨 V45 相关。D0.5cc 与晚期毒性（2+级肛门功能障碍、肠道毒性和腹股沟-会阴部/肛周皮肤炎）显著相关。最大皮肤毒性分级与治疗中断的需求显著相关。
本研究确定了具有统计学意义的剂量-体积参数，可用于提供个体化风险预测并指导治疗计划。需要进一步验证这些结果。
