Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium.
Int J Radiat Oncol Biol Phys. 2012 May 1;83(1):142-8. doi: 10.1016/j.ijrobp.2011.05.068. Epub 2011 Oct 17.
The addition of concomitant chemotherapy to preoperative radiotherapy is considered the standard of care for patients with cT3-4 rectal cancer. The combined treatment modality increases the complete response rate and local control (LC), but has no impact on survival or the incidence of distant metastases. In addition, it is associated with considerable toxicity. As an alternative strategy, we explored prospectively, preoperative helical tomotherapy with a simultaneous integrated boost (SIB).
A total of 108 patients were treated with intensity-modulated and image-guided radiotherapy using the Tomotherapy Hi-Art II system. A dose of 46 Gy, in daily fractions of 2 Gy, was delivered to the mesorectum and draining lymph nodes, without concomitant chemotherapy. Patients with an anticipated circumferential resection margin (CRM) of less than 2 mm, based on magnetic resonance imaging, received a SIB to the tumor up to a total dose of 55.2 Gy. Acute and late side effects were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.
A total of 102 patients presented with cT3-4 tumors; 57 patients entered the boost group and 51 the no-boost group. One patient in the no-boost group developed a radio-hypersensitivity reaction, resulting in a complete tumor remission, a Grade 3 acute and Grade 5 late enteritis. No other Grade ≥3 acute toxicities occurred. With a median follow-up of 32 months, Grade ≥3 late gastrointestinal and urinary toxicity were observed in 6% and 4% of the patients, respectively. The actuarial 2-year LC, progression-free survival and overall survival were 98%, 79%, and 93%.
Preoperative helical tomotherapy displays a favorable acute toxicity profile in patients with cT3-4 rectal cancer. A SIB can be safely administered in patients with a narrow CRM and resulted in a promising LC.
术前放疗联合同期化疗被认为是 cT3-4 直肠癌患者的标准治疗方法。联合治疗方法可提高完全缓解率和局部控制率（LC），但对生存或远处转移发生率没有影响。此外，它还伴有相当大的毒性。作为一种替代策略，我们前瞻性地探索了术前螺旋断层放疗联合同步整合推量（SIB）。
共 108 例患者采用强度调制和图像引导放疗，使用 Tomotherapy Hi-Art II 系统进行治疗。直肠系膜和引流淋巴结接受 46 Gy 的剂量，每天 2 Gy，不联合化疗。基于磁共振成像，预计环周切缘（CRM）小于 2mm 的患者接受 SIB 治疗，肿瘤总剂量为 55.2Gy。使用美国国立癌症研究所不良事件常用术语标准 3.0 对急性和晚期不良反应进行评分。
共有 102 例患者为 cT3-4 肿瘤；57 例患者进入推量组，51 例患者进入非推量组。1 例非推量组患者发生放射性超敏反应，导致完全肿瘤消退，出现 3 级急性和 5 级晚期肠炎。未发生其他 3 级以上急性毒性反应。中位随访 32 个月后，6%和 4%的患者分别出现 3 级以上晚期胃肠道和泌尿系统毒性。2 年 LC、无进展生存率和总生存率的累积分别为 98%、79%和 93%。
术前螺旋断层放疗在 cT3-4 直肠癌患者中具有良好的急性毒性特征。对于 CRM 狭窄的患者，可以安全地给予 SIB，并且 LC 结果有希望。
