Conventional 3D conformal versus intensity-modulated radiotherapy for the adjuvant treatment of gynecologic malignancies: a comparative dosimetric study of dose-volume histograms
Conventional 3D conformal versus intensity-modulated radiotherapy for the adjuvant treatment of gynecologic malignancies: a comparative dosimetric study of dose-volume histograms
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DOI：
10.1016/s0090-8258(03)00461-x
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发表时间：
2003-10-01
影响因子：
4.7
通讯作者：
Kalnicki, S
中科院分区：
文献类型：
--
作者：
Heron, DE;Gerszten, K;Kalnicki, S
目标。本研究的目的是评估盆腔调强放射治疗（IMRT）辅助治疗妇科恶性肿瘤的可行性，比较剂量体积直方图（DVH），并根据两种计划技术对靶组织和非靶组织的剂量确定对急性和长期毒性的潜在影响。方法。连续 10 名转诊至匹兹堡大学医学院和 Magee-Womens Hospital 接受妇科恶性肿瘤辅助放疗的患者被选择使用 ADAC 3D 4.2g 版和 NOMOS Corvus IMRT 4.0 版进行基于 CT 的治疗计划。两个系统与妇科放射科医生合作，在轴向 CT 切片上勾勒出正常组织和关键结构的轮廓。这些区域包括内部、外部和髂总结群、直肠、阴道上部 4 厘米、膀胱和小肠。传统的治疗计划包括使用 18-MV 光子的 3D 四视野盒，旨在治疗从 L-5/S-1 边界上方到 AP/PA 视野上坐骨结节底部的体积，以及侧面视野上的成形块，以最大限度地减少直肠和小肠的剂量。使用 6-MV 光子的七场技术用于 IMRT。 IMRT 对小肠的限制设置为直肠 23.0 Gy +/- 5% 和 35.0 Gy +/- 5%，膀胱 37.5 Gy +/- 5%，同时以每日 1.8 Gy 的剂量向骨盆内淋巴结组提供全剂量 (45.0 Gy)。然后比较两种治疗递送系统的剂量-体积直方图。结果。在 3D 和 IMRT 治疗计划中比较接受超过 30 Gy 剂量的每个感兴趣器官（小肠、膀胱和直肠）的体积。与 3D 相比，IMRT 接受超过 30 Gy 剂量的小肠平均体积减少了 52%。直肠（减少 66%）和膀胱（减少 36%）也具有类似的优势。有风险的淋巴结区域和上阴道均接受了 45.0 Gy 的规定剂量。结论。对于妇科恶性肿瘤的辅助放疗，调强放疗似乎比传统 3D 放疗 (3D CRT) 计划具有多种优势。其中包括膀胱、直肠和小肠的治疗量显着减少。预计正常组织受辐射体积的减少将转化为急性和潜在的晚期治疗相关毒性的总体减少。为了更好地评估更多患者群体的优势，有必要进行前瞻性试验。 (C) 2003 Elsevier Inc. 保留所有权利。
Objectives. The goals of this study were to evaluate the feasibility of pelvic intensity-modulated radiotherapy (IMRT) in the adjuvant treatment of gynecologic malignancies and to compare the dose-volume histograms (DVHs) and determine the potential impact on acute and long-term toxicity based on the dose to target and nontarget tissues for both planning techniques.Methods. Ten consecutive patients referred for adjuvant radiotherapy for gynecologic malignancies at the University of Pittsburgh School of Medicine and Magee-Womens Hospital were selected for CT-based treatment planning using the ADAC 3D version 4.2g and the NOMOS Corvus IMRT version 4.0. Normal tissues and critical structures were contoured on axial CT slices by both systems in conjunction with a gynecologic radiologist. These regions included internal, external, and common iliac nodal groups, rectum, upper 4 cm of vagina, bladder, and small bowel. Conventional treatment planning included 3D four-field box using 18-MV photons designed to treat a volume from the L-5/S-1 border superiorly to the bottom of the ischial tuberosity on the AP/PA field and shaped blocks on the lateral fields to minimize the dose to the rectum and small bowel. A seven-field technique using 6-MV photons was used for IMRT. Restraints on small bowel for IMRT were set at 23.0 Gy +/- 5% and 35.0 Gy +/- 5% for the rectum and 37.5 Gy +/- 5% for the bladder while simultaneously delivering full dose (45.0 Gy) to the intrapelvic nodal groups in 1.8-Gy daily fractions. The dose-volume histograms where then compared for both treatment delivery systems.Results. The volume of each organ of interest (small bowel, bladder, and rectum) receiving doses in excess of 30 Gy was compared in the 3D and IMRT treatment plans. The mean volume of small bowel receiving doses in excess of 30 Gy was reduced by 52% with IMRT compared with 3D. A similar advantage was noted for the rectum (66% reduction) and the bladder (36% reduction). The nodal regions at risk and the upper vagina all received the prescribed dose of 45.0 Gy.Conclusions. Intensity-modulated radiotherapy appears to offer several advantages over conventional 3D radiotherapy (3D CRT) planning for adjuvant radiotherapy for gynecologic malignancies. These include a significant reduction in treatment volume for bladder, rectum, and small bowel. It is anticipated that this reduction in volume of normal tissue irradiated would translate into overall reduction in acute and potentially late treatment-related toxicity. Prospective trials are necessary to better evaluate the advantages in a larger group of patients. (C) 2003 Elsevier Inc. All rights reserved.