18F-Fluoromisonidazole positron emission tomography/CT-guided volumetric-modulated arc therapy-based dose escalation for hypoxic subvolume in nasopharyngeal carcinomas: A feasibility study
18F-Fluoromisonidazole positron emission tomography/CT-guided volumetric-modulated arc therapy-based dose escalation for hypoxic subvolume in nasopharyngeal carcinomas: A feasibility study
复制标题
F-18-氟异硝唑正电子发射断层扫描/CT引导的体积调制弧治疗鼻咽癌缺氧亚体积的剂量递增：可行性研究
DOI：
10.1002/hed.24925
复制
发表时间：
2017-12-01
影响因子：
2.9
通讯作者：
Zhuo, Weihai
中科院分区：
文献类型：
--
作者：
Qiu, Jianjian;Lv, Bo;Zhuo, Weihai
背景资料：本研究的目的是探讨在F-18-氟咪唑（FMISO）正电子发射断层扫描（PET）/CT引导下，采用容积调强弧形治疗（VMAT）和调强放疗（IMRT）技术，同时对鼻咽癌（NCPs）乏氧亚体积进行综合性增强的可行性。8例鼻咽癌患者接受了同步增强调强放疗（治疗计划名为IMRT 70），总肿瘤体积（GTV）的剂量处方为70戈伊、66戈伊、60戈伊和54戈伊，颈部淋巴结阳性，计划靶体积（PTV）和临床阴性颈部。基于相同的数据集，分别使用IMRT和VMAT技术（由IMRT 84和VMAT 84表示）生成具有相同剂量处方加上14戈伊剂量增加（处方剂量的20%递增）的实验计划，以达到预处理F-18-FMISO PET/CT成像上勾画的低氧体积目标。在VMAT计划中使用两个或多个弧（约2-2.5弧，总旋转角度< 1000度），在IMRT计划中使用9个等距分开的射野。结果：IMRT 84和VMAT 84的剂量学参数、总监测单位和输送时间均达到了规定的84戈伊剂量，且符合其他剂量限制。在靶区覆盖率、剂量均匀性和危及器官（OAR）保留方面，IMRT 70的实际治疗计划与实验计划之间无统计学显著差异。VMAT 84的总监测单位（525.7 +/- 39.8）显著小于IMRT 70（1171.5 +/- 167; P = .001）和IMRT 84（1388.3 +/- 151.0; P = .001），分别减少55.1%和62.1%。VMAT计划的平均机器交付时间为3.5分钟，而IMRT计划约为8分钟，减少了56.2%。对于实验计划，3D伽玛指数平均值超过98.0%，无统计学显著差异时，3%/3 mm伽玛通过率criterisedused.Conclusion：与F-18-FMISO PET/CT成像的指导下，剂量递增到NPC内的缺氧区可以实现和有效地提供与VMAT技术相比，调强放射治疗技术。
Background: The purpose of this study is to investigate the feasibility of a simultaneously integrated boost to the hypoxic subvolume of nasopharyngeal carcinomas (NCPs) under the guidance of F-18-fluoromisonidazole (FMISO) positron emission tomography (PET)/CT using volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) techniques.Methods: Eight patients with NPC were treated with simultaneous integrated boostIMRT (treatment plan named IMRT70) with dose prescriptions of 70 Gy, 66 Gy, 60 Gy, and 54 Gy to the gross tumor volume (GTV), positive neck nodes, the planning target volume (PTV), and the clinically negative neck, respectively. Based on the same datasets, experimental plans with the same dose prescription plus a dose boost of 14 Gy (an escalation of 20% of the prescription dose) to the hypoxic volume target contoured on the pretreatment F-18-FMISO PET/CT imaging were generated using IMRT and VMAT techniques, respectively (represented by IMRT84 and VMAT84). Two or more arcs (approximately 2-2.5 arcs, totally rotating angle < 1000 degrees) were used in VMAT plans and 9 equally separated fields in IMRT plans. Dosimetric parameters, total monitor units, and delivery time were calculated for comparative study of plan quality and delivery efficiency between IMRT84 and VMAT84.Results: In experimental plans, hypoxic target volumes successfully received the prescribed dose of 84 Gy in compliance with other dose constraints with either the IMRT technique or the VMAT technique. In terms of the target coverage, dose homogeneity, and organs at risk (OAR) sparing, there was no statistically significant difference between the actual treatment plan of IMRT70 and experimental plans. The total monitor unit of VMAT84 (525.7 +/- 39.8) was significantly less than IMRT70 (1171.5 +/- 167; P = .001) and IMRT84 (1388.3 +/- 151.0; P = .001) per fraction, with 55.1% and 62.1% reduction. The average machine delivery time was 3.5 minutes for VMAT plans in comparison with approximately 8 minutes for IMRT plans, resulting in a reduction factor of 56.2%. For experimental plans, the 3D gamma index average was over 98.0% with no statistical significant difference when a 3%/3 mm gamma passing rate criteria was used.Conclusion: With the guidance of F-18-FMISO PET/CT imaging, dose escalation to hypoxic zones within NPC could be achieved and delivered efficiently with the VMAT technique in comparison with the IMRT technique.