Volumetric-modulated arc radiotherapy for carcinomas of the anal canal: A treatment planning comparison with fixed field IMRT
Volumetric-modulated arc radiotherapy for carcinomas of the anal canal: A treatment planning comparison with fixed field IMRT
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DOI：
10.1016/j.radonc.2008.12.020
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发表时间：
2009-07-01
影响因子：
5.7
通讯作者：
Cozzi, Luca
中科院分区：
文献类型：
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作者：
Clivio, Alessandro;Fogliata, Antonella;Cozzi, Luca
目的：进行一项治疗计划研究，以比较体积调制弧形放射治疗与传统固定野 IMRT。材料和方法：纳入 10 名肛管癌患者的 CT 数据集，并为每个病例生成五个计划：固定束 IMRT、采用 RapidArc 技术的单 (RA1) 和双 (RA2) 调制弧。剂量处方根据同步综合加强策略设定，原发肿瘤 PTVI 剂量为 59.4 Gy（1.8 Gy/分次），危险区域包括腹股沟淋巴结 PTVII 剂量为 49.5 Gy。 PTV 的规划目标是最小剂量 >95%，最大剂量 < 107%；对于危及器官 (OAR)：膀胱（平均 < 45 Gy，D-2% < 56 Gy，D-30% < 35 Gy）、股骨（D-2% < 47 Gy）、小肠（平均 < 30 Gy，D2% < 56 Gy）。 MU 和给药时间对治疗效率进行评分。结果：所有技术均达到最大剂量目标。在 M 最小剂量上观察到一些偏差。PTVI 的均匀性 (D-5-D-95) 对于 IMRT 为 6.6 +/- 1.4%，对于 RA 计划范围为 5.7 +/- 0.3% 至 8.1 +/- 0.8%（+/- 1 标准差）。合格指数 (CI95%) 为 1.3 +/- 0.1 (IMRT) 和 1.4 +/- 0.1（所有 RA 技术）。膀胱：所有技术的结果等效于 40 Gy 以上； V-30GY 与双弧相似 57%，与 RA1 相似 61%，与 IMRT 相似 65%。股骨：所有 RA 计划的最大剂量约为 41-42 Gy，与 IMRT 的 45 Gy 类似。小肠：所有技术均遵循计划目标。计算的 MU/分数数量为 1531 +/- 206 (IMRT)、468 95 (RA1) 和 545 80 (RA2)，导致治疗时间存在差异：IMRT 为 9.4 +/- 1.7 分钟，而 RA1 为 1.1 +/- 0.0 分钟，双弧为 2.6 +/- 0.0 分钟。结论：RapidArc 显示了风险器官的改善当应用双电弧时，可以保护健康组织，并提供不受影响的目标覆盖范围。无论如何，IMRT 计划也取得了最佳结果。 (C) 2009 Elsevier Ireland Ltd. 保留所有权利。放射治疗与肿瘤学92（2009）118-124
Purpose: A treatment planning study was performed to compare volumetric-modulated arc radiotherapy against conventional fixed field IMRT.Materials and methods: CT datasets of 10 patients affected by carcinoma of the anal canal were included and five plans were generated for each case: fixed beam IMRT, single (RA1)- and double (RA2)-modulated arcs with the RapidArc technique. Dose prescription was set according to a simultaneous integrated boost strategy to 59.4 Gy to the primary tumour PTVI (at 1.8 Gy/fraction) and to 49.5 Gy to risk area including inguinal nodes, PTVII. Planning objectives for PTV were minimum dose >95%, maximum dose < 107%; for organs at risk (OARs): bladder (mean < 45 Gy, D-2% < 56 Gy, D-30% < 35 Gy), femurs (D-2% < 47 Gy), small bowel (mean < 30 Gy, D2% < 56 Gy). MU and delivery time scored treatment efficiency.Results: All techniques fulfilled objectives on maximum dose. Some deviations were observed on minimum dose for M. Uniformity (D-5-D-95) on PTVI resulted 6.6 +/- 1.4% for IMRT and ranged from 5.7 +/- 0.3% to 8.1 +/- 0.8% for RA plans (+/- 1 standard deviation). Conformity index (CI95%) Was 1.3 +/- 0.1 (IMRT) and 1.4 +/- 0.1 (all RA techniques). Bladder: all techniques resulted equivalent above 40 Gy; V-30GY similar to 57% for the double arcs, similar to 61% for RA1 and similar to 65% for IMRT. Femurs: maximum dose was of the order of 41-42 Gy for all RA plans and similar to 45 Gy for IMRT. Small bowel: all techniques respected planning objectives. The number of computed MU/fraction was 1531 +/- 206 (IMRT), 468 95 (RA1), and 545 80 (RA2) leading to differences in treatment time: 9.4 +/- 1.7 min for IMRT vs. 1.1 +/- 0.0 min for RA1 and 2.6 +/- 0.0 min for double arcs.Conclusion: RapidArc showed improvements in organs at risk and healthy tissue sparing with uncompromised target coverage when double arcs are applied. Optimal results were also achieved anyway with IMRT plans. (C) 2009 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 92 (2009) 118-124