Departments of Nuclear Medicine, Chungbuk National University Hospital, Cheongju.
Department of Nuclear Medicine, Seoul National University Hospital.
Nucl Med Commun. 2021 Dec 1;42(12):1396-1403. doi: 10.1097/MNM.0000000000001471.
Typical clinical dosimetry models for trans-arterial radioembolization (TARE) assume uniform dose distribution in each tissue compartment. We performed simple voxel-based dosimetry using post-treatment 90Y PET following TARE with 90Y-resin microspheres and investigated its prognostic value in a pilot cohort.
Ten patients with 14 hepatocellular carcinoma lesions who underwent TARE with 90Y-resin microspheres were retrospectively included. The partition model-based expected target tumor dose (TDp) was calculated using a pretreatment 99mTc-macroaggregated albumin scan. From post-treatment 90Y-microsphere PET and voxel-wise S-value kernels, voxel-based dose maps were produced and the absorbed dose of each lesion (TDv) was calculated. Heterogeneity of intratumoral absorbed doses was assessed using the SD and coefficient of variation of voxel doses. The response of each lesion was determined based on contrast-enhanced MRI or CT, or both. Lesion responses were classified as local control success or failure. Prognostic values of dosimetry parameters and clinicopathological factors were evaluated in terms of progression-free survival (PFS) of each lesion.
TDv was significantly different between local control success and failure groups, whereas tumor size, TDp and intratumoral dose heterogeneity were not. Univariate survival analysis identified serum aspartate transaminase level ≥40 IU/L, tumor size ≥66 mm and TDv <81 Gy as significant prognostic factors for PFS. However, only TDv was an independent predictive factor in the multivariate analysis (P = 0.022). There was a significant correlation between TDv and PFS (P = 0.009; r = 0.669).
In TARE, voxel-based dose index TDv can be estimated on post-treatment 90Y PET using a simple method. TDv was a more effective prognostic factor for TARE than TDp and clinicopathologic factors in this pilot study. Further studies are warranted on the role of voxel-based dose and dose distribution in TARE.
经动脉放射性栓塞术（TARE）的典型临床剂量模型假设每个组织隔室的剂量分布均匀。我们使用 TARE 后用 90Y 树脂微球进行的 90Y-PET 进行了简单的体素剂量计算，并在一个试点队列中研究了其预后价值。
回顾性纳入 10 例 14 个肝细胞癌病变患者，行 TARE 用 90Y 树脂微球。使用预处理 99mTc-大颗粒白蛋白扫描计算基于分区模型的预期靶肿瘤剂量（TDp）。从 post-treatment 90Y-microsphere PET 和体素 S 值核中生成体素剂量图，并计算每个病变的吸收剂量（TDv）。使用体素剂量的标准差和变异系数评估肿瘤内吸收剂量的异质性。根据增强 MRI 或 CT 或两者确定每个病变的反应。根据局部控制的成功或失败对病变进行分类。评估剂量学参数和临床病理因素的预后价值是基于每个病变的无进展生存期（PFS）。
TDv 在局部控制成功和失败组之间有显著差异，而肿瘤大小、TDp 和肿瘤内剂量异质性则没有。单因素生存分析确定血清天冬氨酸转氨酶水平≥40IU/L、肿瘤大小≥66mm 和 TDv<81Gy 是 PFS 的显著预后因素。然而，只有 TDv 是多因素分析中的独立预测因子（P=0.022）。TDv 与 PFS 之间存在显著相关性（P=0.009；r=0.669）。
在 TARE 中，使用简单的方法可以在 TARE 后用 90Y-PET 估计基于体素的剂量指标 TDv。在本研究中，TDv 是比 TDp 和临床病理因素更有效的 TARE 预后因素。需要进一步研究 TARE 中基于体素的剂量和剂量分布的作用。
