Patterns of local-regional recurrence following parotid-sparing conformal and segmental intensity-modulated radiotherapy for head and neck cancer
Patterns of local-regional recurrence following parotid-sparing conformal and segmental intensity-modulated radiotherapy for head and neck cancer
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DOI：
10.1016/s0360-3016(99)00550-7
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发表时间：
2000-03-15
影响因子：
7
通讯作者：
Eisbruch, A
中科院分区：
文献类型：
--
作者：
Dawson, LA;Anzai, Y;Eisbruch, A
目的：分析接受保留腮腺适形和节段调强放射治疗 (IMRT) 的头颈癌患者的局部区域复发模式。方法和材料：58 名头颈癌患者仅使用适形或节段 IR IRT 技术接受双侧颈部放射 (RT) 治疗，同时保留一侧腮腺的很大一部分。基于 CT 的 RT 计划的目标包括总肿瘤体积 (GTV)（原发肿瘤和淋巴结转移）和临床靶体积 (CTV)（术后瘤床、GTV 扩张和有亚临床疾病风险的淋巴结组）。有亚临床疾病风险的淋巴结目标包括双侧颈二胃淋巴结和下颈静脉淋巴结、有风险的双侧咽后淋巴结以及风险最高的颈部一侧颅底高颈静脉淋巴结（包含临床颈部转移和/或原发肿瘤同侧）。 CTV 扩大 5 毫米，以产生计划目标体积 (PTV)，计划目标包括覆盖所有 PTV（至少达到处方剂量的 95%），并以较低的风险保留颈部一侧腮腺的大部分。肉眼肿瘤、手术床和亚临床疾病 PTV 的中位放疗剂量分别为 70.4 Gy、61.2 GS 和 50.4 Gy。所有复发均在复发时获得的 CT 扫描上定义，转移到用于 RT 计划的治疗前 CT 数据集，并使用剂量体积直方图进行分析。复发被分类为 1)“场内”，其中 95% 或更多的复发体积 (V-recur) 在 95% 等剂量内； 2)“边缘”，其中 20% 至 95% 的 V-recur 在 95% 等剂量范围内；或 3)“外部”，其中少于 20% 的 V 复发在 95% 等剂量范围内。结果：中位随访 27 个月（范围 6 至 60 个月），12 名患者出现 10 例区域复发、5 例局部复发（包括 1 例非侵入性复发）和 1 例造口复发，2 年精算局部区域控制率为 79%（95% 置信度）区间 68-90%）。 10 名患者 (80%) 在 9 名患者中复发了先前肉眼肿瘤的现场锡区域，两名患者在高危咽后淋巴结/颅底的颈部一侧出现边缘复发，一名患者在下颌下淋巴结出现边缘复发。四个区域复发延伸至颈二腹淋巴结上方，位于颈侧颅底附近的高颈静脉和咽后淋巴结，风险最高。其中三个是在现场接受治疗亚临床疾病剂量的区域。在风险较低的颈部侧颈二腹淋巴结上方的淋巴结中没有发现复发，其中放疗部分幸免。结论：适形和节段调强放疗后的大多数局部区域复发发生在“现场”，在放疗计划时被判断为高风险的区域，包括 GTV、手术床和第一梯队淋巴结。这些发现激发了对最高风险区域剂量递增的研究。 (C) 2000 爱思唯尔科学公司。
Purpose: To analyze the patterns of local-regional recurrence in patients with head and neck cancer treated with parotid-sparing conformal and segmental intensity-modulated radiotherapy (IMRT).Methods and Materials: Fifty-eight patients with head and neck cancer mere treated with bilateral neck radiation (RT) using conformal or segmental IR IRT techniques, while sparing a substantial portion of one parotid gland. The targets for CT-based RT planning included the gross tumor volume (GTV) (primary tumor and lymph node metastases) and the clinical target volume (CTV) (postoperative tumor bed, expansions of the GTVs and lymph node groups at risk of subclinical disease). Lymph node targets at risk of subclinical disease included the bilateral jugulodigastric and lower jugular lymph nodes, bilateral retropharyngeal lymph nodes at risk, and high jugular nodes at the base of skull in the side of the neck at highest risk (containing clinical neck metastases and/or ipsilateral to the primary tumor). The CTVs were expanded by 5 mm to yield planning target volumes (PTVs), Planning goals included coverage of all PTVs (with a minimum of 95% of the prescribed dose) and sparing of a substantial portion of the parotid gland in the side of the neck at less risk. The median RT doses to the gross tumor, the operative bed, and the subclinical disease PTVs were 70.4 Gy, 61.2 GS, and 50.4 Gy respectively. All recurrences were defined on CT scans obtained at the time of recurrence, transferred to the pretreatment CT dataset used for RT planning, and analyzed using dose-volume histograms, The recurrences were classified as 1) "in-field," in which 95% or more of the recurrence volume (V-recur) was within the 95% isodose; 2) "marginal," in which 20% to 95% of V-recur was within the 95% isodose; or 3) "outside," in which less than 20% of V-recur was within the 95% isodose,Results: With a median follow-up of 27 months (range 6 to 60 months), 10 regional recurrences, 5 local recurrences (including one noninvasive recurrence) and 1 stomal recurrence were seen in 12 patients, for a 2-year actuarial local-regional control rate of 79% (95% confidence interval 68-90%). Ten patients (80%) relapsed in-field tin areas of previous gross tumor in nine patients), and two patients developed marginal recurrences in the side of the neck at highest risk tone in the high retropharyngeal nodes/base of skull and one in the submandibular nodes). Four regional recurrences extended superior to the jugulodigastric node, in the high jugular and retropharyngeal nodes near the base of skull of the side of the neck at highest risk. Three of these were in-field, in areas that had received the dose intended for subclinical disease. No recurrences were seen in the nodes superior to the jugulodigastric nodes in the side of the neck at less risk, where RT was partially spared,Conclusions: The majority of local-regional recurrences after conformal and segmental IMRT were "in-field," in areas judged to be at high risk at the time of RT planning, including the GTV, the operative bed, and the first echelon nodes, These findings motivate studies of dose escalation to the highest risk regions. (C) 2000 Elsevier Science Inc.