Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Int J Radiat Oncol Biol Phys. 2012 Nov 15;84(4):955-61. doi: 10.1016/j.ijrobp.2012.01.045. Epub 2012 Apr 24.
To perform a prospective phase II study to investigate the efficacy and safety of preoperative pelvic radiation therapy and concomitant small-field boost irradiation with 5-fluorouracil and leucovorin for 5 weeks in locally advanced rectal cancer patients.
Sixty-nine patients with locally advanced, nonmetastatic, mid-to-lower rectal cancer were prospectively enrolled. They had received preoperative chemoradiation therapy and total mesorectal excision. Pelvic radiation therapy of 43.2 Gy in 24 fractions plus concomitant boost radiation therapy of 7.2 Gy in 12 fractions was delivered to the pelvis and tumor bed for 5 weeks. Two cycles of 5-fluorouracil and leucovorin were administered for 3 days in the first and fifth week of radiation therapy. The pathologic response, survival outcome, and treatment toxicity were evaluated for the study endpoints.
Of 69 patients, 8 (11.6%) had a pathologically complete response. Downstaging rates were 40.5% for T classification and 68.1% for N classification. At the median follow-up of 69 months, 36 patients have been followed up for more than 5 years. The 5-year disease-free survival (DFS) and overall survival rates were 66.0% and 75.3%, respectively. Higher pathologic T (P=.045) and N (P=.032) classification were significant adverse prognostic factors for DFS, and high-grade histology was an adverse prognostic factor for both DFS (P=.025) and overall survival (P=.031) on the multivariate analysis. Fifteen patients (21.7%) experienced grade 3 or 4 acute toxicity, and 7 patients (10.1%) had long-term toxicity.
Preoperative pelvic radiation therapy with concomitant boost irradiation with 5-fluorouracil and leucovorin for 5 weeks showed acceptable acute and long-term toxicities. However, the benefit of concomitant small-field boost irradiation for 5 weeks in rectal cancer patients was not demonstrated beyond conventional irradiation for 6 weeks in terms of tumor response and survival.
进行一项前瞻性 II 期研究，以调查局部晚期直肠癌患者术前盆腔放疗和 5 周氟尿嘧啶和亚叶酸同步小野加量照射的疗效和安全性。
69 例局部晚期、无转移、中下段直肠腺癌患者前瞻性入组。所有患者均接受术前放化疗和全直肠系膜切除术。盆腔照射 43.2Gy/24 次，同时瘤床推量照射 7.2Gy/12 次，共 5 周。在放疗的第 1 周和第 5 周各给予氟尿嘧啶和亚叶酸 2 个周期 3 天。评估研究终点的病理反应、生存结果和治疗毒性。
69 例患者中，8 例（11.6%）病理完全缓解。T 分期和 N 分期的降期率分别为 40.5%和 68.1%。中位随访 69 个月时，36 例患者随访超过 5 年。5 年无病生存率（DFS）和总生存率分别为 66.0%和 75.3%。较高的病理 T 分期（P=.045）和 N 分期（P=.032）是 DFS 的不良预后因素，高级别组织学是 DFS（P=.025）和总生存（P=.031）的不良预后因素。15 例（21.7%）患者出现 3 级或 4 级急性毒性，7 例（10.1%）患者出现长期毒性。
术前盆腔放疗联合氟尿嘧啶和亚叶酸同步小野加量照射 5 周显示出可接受的急性和长期毒性。然而，与 6 周常规照射相比，5 周的同步小野加量照射在肿瘤反应和生存方面并未显示出获益。
