Retrospective Voxel-Based Dosimetry for Assessing the Ability of the Body-Surface-Area Model to Predict Delivered Dose and Radioembolization Outcome
Retrospective Voxel-Based Dosimetry for Assessing the Ability of the Body-Surface-Area Model to Predict Delivered Dose and Radioembolization Outcome
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DOI：
10.2967/jnumed.117.202937
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发表时间：
2018-08-01
影响因子：
9.3
通讯作者：
Ben Bouallegue, Faycal
中科院分区：
文献类型：
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作者：
Kafrouni, Marilyne;Allimant, Carole;Ben Bouallegue, Faycal
本研究的目的是通过回顾性基于体素的剂量测定来定量评估体表面积（BSA）模型预测肿瘤吸收剂量和治疗结果的能力。方法：纳入 35 例肝细胞癌患者共 42 次 Y-90 树脂微球放射栓塞治疗的数据。注入活动是用 BSA 模型计划的。使用专用治疗计划系统回顾性地进行了基于 Tc-99m 标记的大聚集白蛋白 SPECT 和 Y-90 微球 PET 的体素剂量测定。分析了解剖学上定义的肿瘤的平均剂量和剂量体积直方图（DVH）。从 DVH 中提取的选定剂量指标是肿瘤体积 50% 和 70% 的最小剂量以及接受至少 120 Gy 的体积百分比。治疗后6个月根据欧洲肝脏研究协会的标准评估治疗反应。结果：在 26 种治疗中评估了 6 个月的反应：14 种被认为产生客观反应，12 种被认为无反应。基于 Y-90 微球 PET 的剂量测定的回顾性评估显示患者间差异较大，肿瘤的中位平均吸收剂量为 60 Gy。在 62% (26/42) 的病例中，如果增加 BSA 方法计算的注射活性，肿瘤、非肿瘤肝脏和肺剂量将符合推荐阈值。客观缓解情况下的平均剂量、肿瘤体积 50% 和 70% 的最小剂量以及接受至少 120 Gy 的体积百分比显着高于无缓解情况。结论：在我们的人群中，平均肿瘤吸收剂量和 DVH 指标与肿瘤反应相关。然而，通过 BSA 方法计算的活性可能会增加以达到推荐的肿瘤剂量阈值。活动规划时应考虑肿瘤摄取、靶区和非靶区体积以及剂量分布异质性。
The aim of this study was to quantitatively evaluate the ability of the body-surface-area (BSA) model to predict tumor-absorbed dose and treatment outcome through retrospective voxel-based dosimetry. Methods: Data from 35 hepatocellular carcinoma patients with a total of 42 Y-90-resin microsphere radioembolization treatments were included. Injected activity was planned with the BSA model. Voxel dosimetry based on Tc-99m-labeled macroaggregated albumin SPECT and Y-90-microsphere PET was retrospectively performed using a dedicated treatment planning system. Average dose and dose-volume histograms (DVHs) of the anatomically defined tumors were analyzed. The selected dose metrics extracted from DVHs were minimum dose to 50% and 70% of the tumor volume and percentage of the volume receiving at least 120 Gy. Treatment response was evaluated 6 mo after therapy according to the criteria of the European Association for the Study of the Liver. Results: Six-month response was evaluated in 26 treatments: 14 were considered to produce an objective response and 12 a nonresponse. Retrospective evaluation of Y-90-microsphere PET-based dosimetry showed a large interpatient variability with a median average absorbed dose of 60 Gy to the tumor. In 62% (26/42) of the cases, tumor, nontumoral liver, and lung doses would have complied with the recommended thresholds if the injected activity calculated by the BSA method had been increased. Average doses, minimum dose to 50% and 70% of the tumor volume, and percentage of the volume receiving at least 120 Gy were significantly higher in cases of objective response than in nonresponse. Conclusion: In our population, average tumor-absorbed dose and DVH metrics were associated with tumor response. However, the activity calculated by the BSA method could have been increased to reach the recommended tumor dose threshold. Tumor uptake, target and nontarget volumes, and dose distribution heterogeneity should be considered for activity planning.