Engels Benedikt, Platteaux Nele, Van den Begin Robbe, Gevaert Thierry, Sermeus Alexandra, Storme Guy, Verellen Dirk, De Ridder Mark
Department of Radiotherapy, UZ Brussel, Vrije Universiteit Brussel, Belgium.
Department of Radiotherapy, UZ Brussel, Vrije Universiteit Brussel, Belgium.
Radiother Oncol. 2014 Jan;110(1):155-9. doi: 10.1016/j.radonc.2013.10.026. Epub 2013 Nov 12.
The addition of chemotherapy to preoperative radiotherapy has been established as the standard of care for patients with cT3-4 rectal cancer. As an alternative strategy, we explored intensity-modulated and image-guided radiotherapy (IMRT-IGRT) with a simultaneous integrated boost (SIB) in a prospective phase II study. Here, we report outcome and late toxicity after a median follow-up of 54 months.
A total of 108 patients were treated preoperatively with IMRT-IGRT, delivering a dose of 46 Gy in fractions of 2 Gy. Patients (n=57) displaying an anticipated circumferential resection margin (CRM) of less than 2mm based on magnetic resonance imaging received a SIB to the tumor up to a total dose of 55.2 Gy.
The absolute incidence of grade ≥3 late gastrointestinal and urinary toxicity was 9% and 4%, respectively, with a 13% rate of any grade ≥3 late toxicity. The actuarial 5-year local control (LC), progression-free survival (PFS) and overall survival (OS) were 97%, 57%, and 68%. On multivariate analysis, R1 resection and pN2 disease were associated with significantly impaired OS.
The use of preoperative IMRT-IGRT with a SIB resulted in a high 5-year LC rate and non-negligible late toxicity.
术前放疗联合化疗已成为cT3 - 4期直肠癌患者的标准治疗方案。作为一种替代策略，我们在前瞻性II期研究中探索了调强放疗和图像引导放疗（IMRT - IGRT）联合同步整合加量（SIB）的方法。在此，我们报告中位随访54个月后的结果及晚期毒性反应。
共有108例患者接受术前IMRT - IGRT治疗，每次分割剂量2 Gy，总剂量46 Gy。根据磁共振成像显示预期环周切缘（CRM）小于2 mm的患者（n = 57），对肿瘤进行SIB，总剂量达55.2 Gy。
≥3级晚期胃肠道和泌尿毒性的绝对发生率分别为9%和4%，任何≥3级晚期毒性反应的发生率为13%。5年精算局部控制率（LC）、无进展生存率（PFS）和总生存率（OS）分别为97%、57%和68%。多因素分析显示，R1切除和pN2疾病与OS显著受损相关。
术前IMRT - IGRT联合SIB治疗导致5年LC率较高，但晚期毒性反应不可忽视。
