Hu Kenneth, Ship Jonathan A, Harrison Louis B
Department of Radiation Oncology, Continuum Cancer Centers of New York, Beth Israel Medical Center, St. Luke's-Roosevelt Hospital Center, The Albert Einstein College of Medicine, New York, NY 10003, USA.
Semin Oncol. 2003 Dec;30(6 Suppl 18):40-8. doi: 10.1053/j.seminoncol.2003.11.012.
Locoregional recurrence remains a major obstacle to achieving cure of locally advanced head and neck cancers despite maximal resection and postoperative external beam radiation therapy (EBRT). Locoregional failure occurs in 30% to 40% of high-risk resected head and neck cancer patients after standard postoperative EBRT. In an effort to overcome this problem, a number of strategies have been designed to enhance the effectiveness of radiation including concurrent postoperative chemoradiation, accelerated radiation schedules, incorporation of targeted biologic therapies, and improved radiation delivery techniques such as intensity modulated radiation and high-dose rate (HDR) intraoperative radiation therapy. Intraoperative radiation therapy (IORT) represents an important approach to improve outcome in head and neck cancer patients treated with definitive surgery. High-dose rate IORT is defined as the delivery of a single, large dose of radiation at the time of surgery when the tumor bed is exposed. In conjunction with EBRT, HDR-IORT offers several advantages including: (1) conformal delivery of a large dose of radiation while the tumor bed is precisely defined, minimizing the risk of a geographic miss; (2) potential for subsequent dose reduction of EBRT; (3) shortening overall treatment time; and (4) dose-escalation. Because mucositis represents the dose-limiting acute toxicity and xerostomia ranks as the most common long-term quality-of-life complaint, a reduction of the EBRT dose may provide an important benefit in reducing toxicity, especially when combined with the radioprotectant amifostine (Ethyol, WR-2721; MedImmune, Inc, Gaithersburg, MD). The purpose of this article is to review the rationale for integrating HDR-IORT with a reduced dose of postoperative EBRT combined with amifostine to improve locoregional control and quality of life outcomes in advanced-stage resected head and neck cancer patients.
尽管进行了最大限度的切除和术后外照射放疗（EBRT），局部区域复发仍然是实现局部晚期头颈癌治愈的主要障碍。在接受标准术后EBRT的高危头颈癌切除患者中，30%至40%会出现局部区域复发。为了克服这一问题，人们设计了多种策略来提高放疗效果，包括术后同步放化疗、加速放疗方案、采用靶向生物治疗以及改进放疗技术，如调强放疗和高剂量率（HDR）术中放疗。术中放疗（IORT）是改善接受根治性手术的头颈癌患者预后的重要方法。高剂量率IORT定义为在手术暴露肿瘤床时给予单次大剂量放疗。与EBRT联合使用时，HDR-IORT具有以下几个优点：（1）在精确界定肿瘤床的同时进行大剂量适形放疗，将遗漏照射的风险降至最低；（2）有可能随后降低EBRT的剂量；（3）缩短总体治疗时间；（4）提高剂量。由于黏膜炎是剂量限制性急性毒性反应，口干是最常见的长期生活质量问题，降低EBRT剂量可能对降低毒性有重要益处，尤其是与放射保护剂氨磷汀（Ethyol，WR-2721；MedImmune公司，马里兰州盖瑟斯堡）联合使用时。本文的目的是综述将HDR-IORT与降低剂量的术后EBRT联合氨磷汀相结合以改善晚期头颈癌切除患者局部区域控制和生活质量结果的理论依据。
