PURPOSE To evaluate the efficacy of coil embolization to obtain intrahepatic redistribution in patients undergoing radioembolization. MATERIALS AND METHOD All patients treated with radioembolization at our institute were retrospectively analyzed, and all cases in which a tumor-feeding vessel was coil-embolized were selected. Two nuclear medicine physicians visually assessed the effect of redistribution. Furthermore, the redistribution of microspheres was measured by quantifying the activity distributed to the coil-embolized (dependent) segment relative to the other (non-dependent) segments and to the tumor(s) in that segment. Quantitative analysis was performed on post-treatment 90Y-PET and 166Ho-SPECT using Simplicit90Y software. Lesion response was measured according to RECIST 1.1 criteria at 3 months post-treatment. RESULTS Out of 37 cases, 32 were suitable for quantitative analysis and 37 for qualitative analysis. In the qualitative analysis, redistribution was deemed successful in 69% of cases. The quantitative analysis showed that the median ratio of the activity to the dependent embolized segments and the non-dependent segments was 0.88 (range 0.26-2.05) and 0.80 (range 0.19-1.62) for tumors in dependent segments compared with tumors in non-dependent segments. Using a cutoff ratio of 0.7 (30% lower activity concentration in comparison with the rest of the liver), 57% of cases were successful. At 3 months post-treatment, 6% of dependent tumors had partial response, 20% progressive disease, and 74% stable disease. In non-dependent tumors, this was, respectively, 16%, 20%, and 64%. CONCLUSION Coil embolization of hepatic arteries to induce redistribution of microspheres has a limited success rate. Qualitative assessment tends to overrate redistribution.

中文翻译：

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线圈栓塞在放射性栓塞中获得肝内再分布的功效：定性和定量分析。

目的评估线圈栓塞术在接受放射栓塞术的患者中获得肝内重新分布的功效。材料与方法对我院放射栓塞治疗的所有患者进行回顾性分析，并选择所有肿瘤供血血管进行螺旋栓塞的病例。两名核医学医师目视评估了重新分配的效果。此外，通过定量相对于其他（非依赖性）节段和在该节段中的一个或多个肿瘤上分配给线圈栓塞的（依赖性）节段的活性来测量微球的重新分布。使用Simplicit90Y软件对90Y-PET和166Ho-SPECT后处理进行定量分析。在治疗后3个月，根据RECIST 1.1标准测量病变反应。结果在37例中，32个适合定量分析，37个适合定性分析。在定性分析中，重新分配在69％的案例中被认为是成功的。定量分析表明，与非依赖性肿瘤相比，非依赖性肿瘤的活性与依赖性栓塞节段和非依赖性节段的活性中值之比为0.88（范围为0.26-2.05）和0.80（范围为0.19-1.62）。段。使用0.7的截断率（与肝脏其他部位相比，活动浓度降低了30％），成功的病例为57％。治疗后3个月，有6％的依赖性肿瘤具有部分缓解，20％的进行性疾病和74％的稳定性疾病。在非依赖性肿瘤中，分别为16％，20％和64％。结论肝动脉的线圈栓塞诱导微球的重新分布具有有限的成功率。定性评估往往会高估再分配。