Definition of the CTV Prostate in CT and MRI by Using CT-MRI Image Fusion in IMRT Planning for Prostate Cancer
Definition of the CTV Prostate in CT and MRI by Using CT-MRI Image Fusion in IMRT Planning for Prostate Cancer
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DOI：
10.1007/s00066-010-2179-1
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发表时间：
2011-03-01
影响因子：
3.1
通讯作者：
Hentschel, Bettina
中科院分区：
文献类型：
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作者：
Hentschel, Bettina;Oehler, Wolfgang;Hentschel, Bettina
目的：确定使用 MRI 和 CT 扫描定义的前列腺体积，以及 MRI 和 CT 中前列腺轮廓在三维 (3D) 上的差异。进一步的目标是使用 MRI 来确定可以避免精囊照射的患者亚组。 方法和材料：共有 294 名活检证实的前列腺癌患者（MRI 分期：T(1), 16 [5%]；T(2), 84 [29%]；T(3), 191 [65%]；T(4), 3 [1%]）接受了盆腔 CT 和 MRI 扫描在调强放射治疗 (IMRT) 计划之前。 3D 图像用于比较由叠加的 MRI 和 CT 图像定义的前列腺体积。前列腺体积以 cm(3) 为单位计算。结果：MRI 定义的平均前列腺体积（44.3 cm(3) [范围，8.8-182.8 cm(3)]）比 CT 定义的平均前列腺体积（68.5 cm(3) [范围，15.2-241.3 cm(3)]）小 35%。主要在前列腺的最上部和下部部分观察到不一致区域。 MRI 发现的精囊侵犯 (SVI) 发生率为 63%（290 人中，n = 182 人）。 SVI 的中位长度为 2.6 cm（范围：1.1-4.7 cm；中位 SV 长度的 62%）。应用 Roach 和 Diaz 公式计算的低风险患者（59%，n = 290 人中的 171 人）的 SVI 率为 57%（n = 171 人中的 n = 97 人），高风险患者（41%，n = 290 人中的 119 人）的 SVI 率为 71%（n = 119 人中的 85 人）。结论：与 MRI 相比，CT 扫描高估了前列腺体积35%。基于 CT-MRI 图像融合的治疗计划可以更准确地预测前列腺癌患者的正确分期和更精确的靶区识别。
Purpose: To determine the prostate volumes defined by using MRI and CT scans, as well as the difference between prostate delineation in MRI and CT in three dimensions (3D). A further goal was to use MRI to identify subgroups of patients in whom seminal vesicle irradiation can be avoided.Methods and Materials: A total of 294 patients with biopsy-proven prostate cancer (MRI stages: T(1), 16 [5%]; T(2), 84 [29%]; T(3), 191 [65%]; T(4), 3 [1%]) underwent pelvic CT and MRI scans before intensity-modulated radiation therapy (IMRT) planning. 3D images were used to compare the prostate volumes defined by superimposed MRI and CT images. Prostate volumes were calculated in cm(3).Results: The mean prostate volume defined by MRI (44.3 cm(3) [range, 8.8-182.8 cm(3)]) was 35% smaller than that defined by CT (68.5 cm(3) [range, 15.2-241.3 cm(3)]). The areas of nonagreement were observed predominantly in the most superior and inferior portions of the prostate. The incidence of seminal vesicle invasion (SVI) identified by MRI was 63% (n = 182 of 290). The median length of SVI was 2.6 cm (range, 1.1-4.7 cm; 62% of the median SV length). The low-risk patients (59%, n = 171 of 290) calculated by applying the Roach and Diaz formula had a SVI rate of 57% (n = 97 of 171), the high-risk patients (41%, n = 119 of 290) of 71% (n = 85 of 119).Conclusions: Compared with MRI, CT scans overestimate prostate volume by 35%. CT-MRI image fusion-based treatment planning allows more accurate prediction of the correct staging and more precise target volume identification in prostate cancer patients.