PURPOSE Dose calculation for transarterial radioembolization (TARE) with glass yttrium-90 (Y90) labeled microspheres is based on liver lobe and tumor volumes, currently measured from preprocedural MRI or CT. The variable time between MRI and radioembolization may not account for relevant tumor progression. Advances in cone beam computed tomography (CBCT) allow for intra-procedural assessment of these volumes that avoids this factor. Liver lobe and hepatocellular carcinoma tumor volume measurements and dose calculations using intra-procedural CBCT were compared to those using preprocedural MRI in order to determine feasibility. METHODS Retrospective analysis was performed in 20 patients with proven hepatocellular carcinoma (HCC) who underwent planning angiography with open trajectory CBCT acquisitions prior to radioembolization, and an MRI performed within 6 weeks prior to treatment planning. Liver lobe and tumor burden volumes were measured based on CBCT using embolization planning and guidance software and measured on preprocedural MRI using standard volume analysis software. Y90 doses were subsequently calculated using each measured volume. Comparisons of volume measurements and calculated Y90 doses between the two modalities were evaluated for significance using paired t tests. RESULTS All target liver lobes and all tumors were completely depicted on CBCT. Mean liver lobe and tumor burden volumes measured on intra-procedural CBCT and preprocedural MRI showed no significant difference (p = 0.71). Mean calculated Y90 dose based on each modality showed no significant difference (p = 0.18). CONCLUSIONS Lobar and tumor volume measurement with CBCT is a reliable alternative to measurement with preprocedural MRI. Utilization of CBCT 3D segmentation software during planning angiography may be useful to provide up-to-date volume measurements and dose calculations prior to radioembolization.

中文翻译：

---

Yttrium-90放射栓塞剂量的使用过程内开放轨迹锥束CT计算的可行性。

目的带有玻璃钇90（Y90）标记的微球的经动脉放射栓塞（TARE）的剂量计算基于肝叶和肿瘤体积，目前是通过术前MRI或CT测量的。MRI和放射栓塞之间的可变时间可能无法解释相关的肿瘤进展。锥形束计算机断层扫描（CBCT）的进步允许对这些体积进行过程内评估，从而避免了这一因素。为了确定可行性，将使用过程内CBCT进行肝叶和肝细胞癌的肿瘤体积测量和剂量计算与使用过程前MRI进行了比较。方法对20例经证实的肝细胞癌（HCC）的患者进行回顾性分析，这些患者在进行放射栓塞之前接受了计划的血管造影，并采用开放轨迹CBCT采集，在计划治疗前的6周内进行MRI检查。使用栓塞计划和指导软件基于CBCT测量肝叶和肿瘤负荷量，并使用标准体积分析软件在术前MRI上测量肝叶和肿瘤负荷量。随后使用每个测得的体积计算Y90剂量。使用配对t检验评估了两种方式之间的体积测量值和计算的Y90剂量的比较的显着性。结果所有目标肝叶和所有肿瘤均在CBCT上完整描绘。术中CBCT和术前MRI测得的平均肝叶和肿瘤负荷量无明显差异（p = 0.71）。根据每种方式计算的平均Y90剂量无显着差异（p = 0.18）。结论CBCT的大叶和肿瘤体积测量是术前MRI测量的可靠替代方法。在计划血管造影过程中使用CBCT 3D分割软件可能有助于在放射栓塞之前提供最新的体积测量和剂量计算。