Utilization of custom electron bolus in head and neck radiotherapy.
Utilization of custom electron bolus in head and neck radiotherapy.
复制标题
DOI：
10.1120/1.1621494
复制
发表时间：
2003-01-01
影响因子：
2.1
通讯作者：
Hogstrom, K R
中科院分区：
文献类型：
--
作者：
Kudchadker, R J;Antolak, J A;Hogstrom, K R
治疗浅表头颈部肿瘤的传统方法，如楔形对技术或使用不同能量的多个电子场，可以达到很好的肿瘤控制效果。然而，在某些情况下，这些技术不必要地照射健康组织和/或在连接区域产生热点和冷点，特别是在表面轮廓修改复杂或计划靶体积（PTV）厚度变化的患者中。这项工作的目的是证明如何将大剂量电子适形治疗用于这些患者。本文介绍了两例使用该技术治疗的患者。第一位患者被诊断为恶性纤维组织细胞瘤，累及右耳耳甲，并接受12mev电子治疗。第二例患者被诊断为左侧腮腺腺泡细胞癌，在完成腮腺全切除术后接受20 mev电子治疗。使用内部治疗计划系统（TPS）中实施的药物设计工具设计每位患者的药物。该丸是用计算机控制的铣床制造的。作为质量保证过程的一部分，以确保丸的正确制作和放置，患者在丸就位时进行了第二次计算机断层扫描（CT）。利用这些数据，使用Philips Pinnacle(3) TPS （Philips Medical Systems, Andover， MA）计算最终剂量分布。结果表明，90%等剂量面符合PTV，对关键结构（如脊髓、脑和肺）的剂量远低于耐受限度。两例患者在放疗后6个月均未出现疾病迹象。综上所述，电子丸适形治疗是治疗头颈部肿瘤的可行选择，特别是有变厚PTV或表面解剖有手术缺陷的患者。
Conventional methods of treating superficial head and neck tumors, such as the wedge pair technique or the use of multiple electron fields of varying energies, can result in excellent tumor control. However, in some cases, these techniques irradiate healthy tissue unnecessarily and/or create hot and cold spots in junction regions, particularly in patients with complex surface contour modification or varying planning target volume (PTV) thickness. The objective of this work is to demonstrate how bolus electron conformal therapy can be used for these patients. Two patients treated using this technique are presented. The first patient was diagnosed with malignant fibrous histiocytoma involving the right ear concha and was treated with 12-MeV electrons. The second patient was diagnosed with acinic cell carcinoma of the left parotid gland and was treated with 20-MeV electrons after having undergone a complete parotidectomy. Each patient's bolus was designed using bolus design tools implemented in an in-house treatment-planning system (TPS). The bolus was fabricated using a computer-controlled milling machine. As part of the quality assurance process to ensure proper fabrication and placement of the bolus, the patients underwent a second computed tomography (CT) scan with the bolus in place. Using that data, the final dose distribution was computed using the Philips Pinnacle(3) TPS (Philips Medical Systems, Andover, MA). Results showed that the 90% isodose surface conformed well to the PTV and that the dose to critical structures such as cord, brain, and lung was well below tolerance limits. Both patients showed no evidence of disease six months post-radiotherapy. In conclusion, electron bolus conformal therapy is a viable option for treating head and neck tumors, particularly patients having a variable thickness PTV or surface anatomy with surgical defects.