Patterns of failure in patients receiving definitive and postoperative IMRT for head-and-neck cancer
Patterns of failure in patients receiving definitive and postoperative IMRT for head-and-neck cancer
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DOI：
10.1016/s0360-3016(02)03940-8
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发表时间：
2003-02-01
影响因子：
7
通讯作者：
Low, DA
中科院分区：
文献类型：
--
作者：
Chao, KSC;Ozyigit, G;Low, DA
目的：分析逆行计划调强放疗(IMRT)治疗头颈癌的局部失败模式。方法与材料：1997年2月至2000年12月，165例经组织学证实的头颈癌患者采用保留腮腺的逆行计划调强放疗方案。39名接受姑息性重复放疗或调强放射治疗的患者被排除在这项分析之外，剩下126名患者参加这项分析。在126名患者中，30名为女性，96名为男性(平均年龄56岁，范围13-84岁)。52名患者(41%)接受了明确的调强放射治疗。在52例患者中，17例仅接受RT治疗，35例同时接受以顺铂为基础的化疗方案。74例患者(59%)接受了术后调强放疗。中位随访时间为26个月(范围12-55个月)。调强放射治疗仅在上颈部保留唾液。下颈部采用传统的AP低颈口，紧靠下调强放射治疗剂量分布边界。根据假定的控制疾病的风险，将放射剂量规定为两个临床目标体积(CTV)。最终确定的调强放疗患者CTV1和CTV2的平均剂量分别为72.64+/-4.83和64.34+/-5.15。术后CTV1和CTV2的平均剂量分别为68.53±4.71GY和60.95±5.33GY。结果：共发现17例区域性失败(持续性或复发性疾病)。在这17例故障中，9例(53%)发生在CTV1内。1例(6%)在CTV1边缘，但在CTV2内。1例(6%)失败发生在CTV1外而CTV2内。另一次失败与CTV2相差无几。在17例失败中，5例(28%)发生在调强放疗野外和下颈部。剂量-体积直方图分析显示，除1名患者外，CTV内复发/持续性疾病的剂量覆盖范围与CTV相当或高于CTV。2年精算局部控制率为85%，手术挽救后最终局部控制率为89%。我们没有观察到皮肤衰竭，仅在邻近保留腮腺的区域观察到一个边缘衰竭。结论：我们已经表明，对于接受调强放射治疗的患者来说，保留腮腺的靶点定义和覆盖范围是足够的。CTV1内的主要肿瘤失效可能意味着需要确定CTV内有放射抵抗的肿瘤亚体积(如缺氧区)的患者。这些信息将有助于区分肿瘤的一个亚组，以便采取更具侵略性和靶向性的治疗方法。(C)2003年爱思唯尔科学公司。
Purpose: To analyze the patterns of locoregional failure in patients with head-and-neck cancer treated with inverse planning intensity-modulated radiotherapy (IMRT).Methods and Materials: Between February 1997 and December 2000, 165 patients with histologically confirmed head-and-neck cancer were treated using a parotid-sparing inverse planning IMRT protocol. Thirty-nine patients who received either palliative repeat irradiation or IMRT as a boost were excluded from this analysis, leaving 126 patients for this analysis. Of the 126 patients, 30 were women and 96 were men (median age 56 years, range 13-84). Fifty-two patients (41%) received definitive IMRT. Of the 52 patients, 17 were treated with RT alone and 35 with concurrent cisplatin-based chemotherapy regimens. Seventy-four patients (59%) received postoperative IMRT. The median follow-up was 26 months (range 12-55). IMRT was used only in the upper neck for salivary sparing. The lower neck was treated with a conventional AP low-neck port abutted to the inferior IMRT dose distribution border. The radiation dose was prescribed to the two clinical target volumes (CTVs) according to the assumed risk of containing disease. The mean dose for definitive IMRT patients was 72.64 +/- 4.83 Gy to CTV1 and 64.34 +/- 5.15 Gy to CTV2. The mean dose to CTV1 and CTV2 in postoperative cases was 68.53 +/- 4.71 Gy and 60.95 +/- 5.33 Gy, respectively. The locations'of failure were analyzed.Results: Seventeen locoregional failures (persistent or recurrent disease) were found. Of these 17 failures, 9 (53%) were inside CTV1. One failure (6%) was marginal to CTV1 but inside CTV2. One failure (6%) occurred outside CTV1 but inside CTV2. Another failure was marginal to CTV2. Of the 17 failures, 5 (28%) were found outside of the IMRT field and in the lower neck. Dose-volume histogram analysis revealed that for all but 1 patient, the recurrent/persistent disease within the CTVs received comparable or superior dose coverage relative to the CTV. The 2-year actuarial locoregional control rate was 85%, and the ultimate locoregional control rate after surgical salvage was 89%. We observed no dermal failure and only one marginal failure in the region adjacent to the spared parotid glands.Conclusion: We have shown that the target definition and coverage for patients treated with IMRT for parotid sparing is adequate. The predominant tumor failure within CTV1 may imply the need to identify patients with radioresistant tumor subvolumes; (such as hypoxic regions) within the CTV. This information would assist in discriminating a subgroup of tumors for a more aggressive and target-specific therapeutic approach. (C) 2003 Elsevier Science Inc.