Patterns of locoregional failure after exclusive IMRT for oropharyngeal carcinoma
Patterns of locoregional failure after exclusive IMRT for oropharyngeal carcinoma
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DOI：
10.1016/j.ijrobp.2008.01.027
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发表时间：
2008-11-01
影响因子：
7
通讯作者：
Parker, Brent
中科院分区：
文献类型：
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作者：
Sanguineti, Giuseppe;Gunn, G. Brandon;Parker, Brent
目的：评估口咽鳞状细胞癌（SCC）调强放疗（IMRT）后的失败模式。方法和材料：我们分析了 2002 年 5 月至 2006 年 2 月期间在德克萨斯大学医学分部接受治疗的患者，这些患者符合以下标准：（1）针对口咽鳞状细胞癌进行了明确的 IMRT，无需化疗； (2)未进行预处理的根治性手术； (3)最少随访1年。每个节点/主要故障的位置均与预处理计划计算机断层扫描共同配准，然后扩大 5 毫米至故障的计划目标体积 (PTV) (PTV-f)。然后，我们调查了 PTV-f 的处方剂量是否适合治疗前存在的疾病数量，以及 PTV-f 是否得到充分覆盖。结果：共有 50 名患者符合条件。中位随访时间为 32.6 个月（范围为 12.1-58.6），8 名患者观察到 3 例局部失败和 6 例区域失败。除一次被忽视的失败外，所有失败均在治疗结束后 14 个月内记录。在九次失败中，有四次发生在颈部，选择性地接受最低剂量水平的治疗，在所有这些失败中，我们可以回顾性地识别出最初的阳性淋巴结，这可能证明了随后的失败是合理的。其余五次失败是在接近高剂量体积时发生的。除一处外，在所有情况下，接受 >= 95% PTV-f 剂量的感兴趣区域的体积均 >95%，表明覆盖范围足够。在I例患者中，大约20%的PTV-f在95%等剂量之外，因此不能排除边际剂量不足的可能性。结论：在最低剂量水平下的所有失败中都可以找出潜在原因。讨论了影响和可能的补救措施。高剂量区域周围的大多数故障都是“真正的故障”，没有明显的技术原因。 (C) 2008 爱思唯尔公司。
Purpose: To assess the patterns of failure after intensity-modulated radiotherapy (IMRT) for oropharyngeal squamous cell carcinoma (SCC).Methods and Materials: We analyzed patients treated at the University of Texas Medical Branch between May 2002 and February 2006 who met the following criteria: (1) definitive IMRT without chemotherapy for oropharyngeal SCC; (2) no pretreatment radical surgery; (3) minimal follow-up of 1 year. The location of each nodal/primary failure was co-registered to the pretreatment planning computed tomography scan and then expanded by 5 mm to a planning target volume (PTV) of the failure (PTV-f). We then investigated whether the prescription dose to the PTV-f had been appropriate for the amount of disease present before treatment and whether the PTV-f had been adequately covered.Results: A total of 50 patients were eligible. With a median follow-up of 32.6 months (range, 12.1-58.6), three local and six regional failures were observed in 8 patients. All but one failure, that had been neglected, were recorded within 14 months of the treatment end. Of the nine failures, four developed in the neck treated electively to the lowest dose level, in all of them, we could retrospectively identify initial positive lymph nodes that might have justified the subsequent failure. The remaining five failures developed in proximity of the high-dose volume. In all but one, the volume of region of interest receiving >= 95% of the dose of the PTV-f was >95%, suggesting adequate coverage. In I patient, about 20% of PTV-f was outside the 95% isodose,so that marginal underdosing could not be ruled out.Conclusions: A potential cause could be identified in all the failures in the lowest dose level. The implications and possible remedies are discussed. Most failures around the high-dose region were "true failures" with no apparent technical cause. (C) 2008 Elsevier Inc.