Postoperative Radiotherapy for Prostate Cancer: A Comparison of Four Consensus Guidelines and Dosimetric Evaluation of 3D-CRT Versus Tomotherapy IMRT
Postoperative Radiotherapy for Prostate Cancer: A Comparison of Four Consensus Guidelines and Dosimetric Evaluation of 3D-CRT Versus Tomotherapy IMRT
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DOI：
10.1016/j.ijrobp.2011.12.081
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发表时间：
2012-11-01
影响因子：
7
通讯作者：
Spaans, Johanna
中科院分区：
文献类型：
--
作者：
Malone, Shawn;Croke, Jennifer;Spaans, Johanna
目的：尽管根治性乳腺癌切除术后辅助放疗的好处，大约一半的患者复发。已经发布了四项共识指南（欧洲癌症研究和治疗组织、放射肿瘤学系生殖泌尿组、玛格丽特公主医院、放射治疗肿瘤学组），旨在标准化临床靶体积（CTV）划定并改善结局。迄今为止，尚未尝试在治疗体积或危及器官（OAR）照射方面对这些指南进行比较。指南衍生计划满足当前试验或临床正常组织效应定量分析（QUANTEC）试验的剂量学限制的程度也是未知的。我们的研究还探讨了调强放疗（IMRT）的剂量学效益。方法和材料：共20例患者接受术后放疗。应用三维适形放射治疗（3D-CRT）计划覆盖指南生成的计划靶体积（66戈伊，33次）。分析剂量体积直方图（DVH）的CTV/计划靶体积覆盖范围，并评估OAR照射。将OAR DVH与QUANTEC和局部手术后联合放疗和雄激素补充剂（RADICALS）试验中提出的限制进行比较。将3D-CRT计划与放射治疗肿瘤学组计划靶区的断层治疗计划进行比较，以评估IMRT的优势。欧洲癌症研究和治疗组织的CTV显著小于其他CTV（p < 0.001）。前列腺床覆盖率的差异是两个指南之间主要体积差异的主要原因。使用3D-CRT，DVH很少符合QUANTEC或RADICALS直肠约束，与所用指南无关。欧洲癌症研究和治疗组织共识指南（20例中的14例）最常满足RADICALS膀胱限制。断层治疗IMRT计划导致显着的OAR保留与3D-CRT计划相比，然而，在很大比例的cases.Conclusion：治疗量使用目前的共识指南显着不同的RADICALS和QUANTEC标准仍然错过。对于四个CTV指南，QUANTEC和RADICALS试验中提出的直肠和膀胱DVH限制很少符合3D-CRT。调强放射治疗的结果在显着的OAR节省;然而，径向剂量限制仍然错过了很大比例的情况下。RADICALS的直肠和膀胱约束应进行修改，以避免CTV减少。(C)2012 Elsevier Inc.
Purpose: Despite the benefits of adjuvant radiotherapy after radical prostatectomy, approximately one-half of patients relapse. Four consensus guidelines have been published (European Organization for Research and Treatment of Cancer, Faculty of Radiation Oncology Genito-Urinary Group, Princess Margaret Hospital, Radiation Therapy Oncology Group) with the aim of standardizing the clinical target volume (CTV) delineation and improve outcomes. To date, no attempt has been made to compare these guidelines in terms of treatment volumes or organ at risk (OAR) irradiation. The extent to which the guideline-derived plans meet the dosimetric constraints of present trials or of the Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) trial is also unknown. Our study also explored the dosimetric benefits of intensity-modulated radiotherapy (IMRT).Methods and Materials: A total of 20 patients treated with postoperative RT were included. The three-dimensional conformal radiotherapy (3D-CRT) plans were applied to cover the guideline-generated planning target volumes (66 Gy in 33 fractions). Dose-volume histograms (DVHs) were analyzed for CTV/planning target volume coverage and to evaluate OAR irradiation. The OAR DVHs were compared with the constraints proposed in the QUANTEC and Radiotherapy and Androgen Deprivation In Combination After Local Surgery (RADICALS) trials. 3D-CRT plans were compared with the tomotherapy plans for the Radiation Therapy Oncology Group planning target volume to evaluate the advantages of IMRT.Results: The CTV differed significantly between guidelines (p < 0.001). The European Organization for Research and Treatment of Cancer-CTVs were significantly smaller than the other CTVs (p < 0.001). Differences in prostate bed coverage superiorly accounted for the major volumetric differences between the guidelines. Using 3D-CRT, the DVHs rarely met the QUANTEC or RADICALS rectal constraints, independent of the guideline used. The RADICALS bladder constraints were met most often by the European Organization for Research and Treatment of Cancer consensus guideline (14 of 20). The tomotherapy IMRT plans resulted in significant OAR sparing compared with the 3D-CRT plans; however, the RADICALS and QUANTEC criteria were still missed in a large percentage of cases.Conclusion: Treatment volumes using the current consensus guidelines differ significantly. For the four CTV guidelines, the rectal and bladder DVH constraints proposed in the QUANTEC and RADICALS trials are rarely met with 3D-CRT. IMRT results in significant OAR sparing; however, the RADICALS dose constraints are still missed for a large percentage of cases. The rectal and bladder constraints of RADICALS should be modified to avoid a reduction in the CTVs. (C) 2012 Elsevier Inc.