PURPOSE This study aimed to generate a functional image of the liver using dual-energy computed tomography (DECT) and a functional-image-based stereotactic body radiation therapy plan to minimize the dose to the volume of the functional liver (Vfl). MATERIAL AND METHODS A normalized iodine density (NID) map was generated for fifteen patients with liver tumors. The volume of liver with an NID < 0.46 was defined as Vfl, and the ratio between Vfl and the total volume of the liver (FLR) was calculated. The relationship between the FLR and Fibrosis-4 (FIB-4) was assessed. For patients with 15% < FLR < 85%, functional volumetric modulated-arc therapy plans (F-VMAT) were retrospectively generated to preserve Vfl, and compared to the clinical plans (C-VMAT). RESULTS FLR showed a significantly strong correlation with FIB-4 (r = -0.71, p < 0.01). For ten generated F-VMAT plans, the dosimetric parameters of D99%, D50%, D1% and the conformity index were comparable to those of the C-VMAT (p > 0.05). For Vfl, F-VMAT plans achieved lower V5Gy (122.4 ± 31.7 vs 181.1 ± 57.3 cc), V10Gy (44.4 ± 22.2 vs 98.2 ± 33.3 cc), V15Gy (22.6 ± 20.3 vs 49.8 ± 33.7 cc), V20Gy (11.6 ± 14.1 vs 24.9 ± 25.1 cc), and Dmean (3.9 ± 2.3 vs 5.8 ± 3.0 Gy) values than the C-VMAT plans (p < 0.01). CONCLUSIONS The functional image derived from DECT was successfully used, allowing for a reduction in the dose to the Vfl without compromising target coverage.

中文翻译：

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使用双能计算机断层扫描的功能图像对肝脏肿瘤进行立体定向放射治疗规划

目的 本研究旨在使用双能计算机断层扫描 (DECT) 和基于功能图像的立体定向放射治疗计划生成肝脏的功能图像，以最大限度地减少功能性肝脏 (Vfl) 的体积剂量。材料和方法 为 15 名肝肿瘤患者生成了标准化碘密度 (NID) 图。将 NID < 0.46 的肝脏体积定义为 Vfl，并计算 Vfl 与肝脏总体积 (FLR) 之间的比率。评估了 FLR 和 Fibrosis-4 (FIB-4) 之间的关系。对于 15% < FLR < 85% 的患者，回顾性生成功能性容积调节弧治疗计划 (F-VMAT) 以保留 Vfl，并与临床计划 (C-VMAT) 进行比较。结果 FLR 与 FIB-4 显着强相关（r = -0.71，p < 0.01）。对于十个生成的 F-VMAT 计划，D99%、D50%、D1% 的剂量学参数和符合性指数与 C-VMAT 的相当（p > 0.05）。对于 Vfl，F-VMAT 计划实现了较低的 V5Gy（122.4 ± 31.7 对 181.1 ± 57.3 cc）、V10Gy（44.4 ± 22.2 对 98.2 ± 33.3 cc）、V15Gy（22.6 ± 20.3 对 3.1 ± 39 cc）、1.6 ± 39 cc） vs 24.9 ± 25.1 cc) 和 Dmean (3.9 ± 2.3 vs 5.8 ± 3.0 Gy) 值比 C-VMAT 计划 (p < 0.01)。结论 来自 DECT 的功能图像被成功使用，允许在不影响目标覆盖范围的情况下减少 Vfl 的剂量。3 cc)、V15Gy (22.6 ± 20.3 vs 49.8 ± 33.7 cc)、V20Gy (11.6 ± 14.1 vs 24.9 ± 25.1 cc) 和 Dmean (3.9 ± 2.3 vs 5.8 ± 3.0 Gy 计划 (C-V) 0.01）。结论 来自 DECT 的功能图像被成功使用，允许在不影响目标覆盖范围的情况下减少 Vfl 的剂量。3 cc)、V15Gy (22.6 ± 20.3 vs 49.8 ± 33.7 cc)、V20Gy (11.6 ± 14.1 vs 24.9 ± 25.1 cc) 和 Dmean (3.9 ± 2.3 vs 5.8 ± 3.0 Gy 计划 (C-V) 0.01）。结论 来自 DECT 的功能图像被成功使用，允许在不影响目标覆盖范围的情况下减少 Vfl 的剂量。