Brosch Julia, Gosewisch Astrid, Kaiser Lena, Seidensticker Max, Ricke Jens, Zellmer Johannes, Bartenstein Peter, Ziegler Sibylle, Ilhan Harun, Todica Andrei, Böning Guido
Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany.
Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany.
Phys Med. 2020 Dec;80:317-326. doi: 10.1016/j.ejmp.2020.11.016. Epub 2020 Nov 25.
To improve therapy outcome of Yttrium-90 selective internal radiation therapy (Y SIRT), patient-specific post-therapeutic dosimetry is required. For this purpose, various dosimetric approaches based on different available imaging data have been reported. The aim of this work was to compare post-therapeutic 3D absorbed dose images using Technetium-99m (Tc) MAA SPECT/CT, Yttrium-90 (Y) bremsstrahlung (BRS) SPECT/CT, and Y PET/CT.
Ten SIRTs of nine patients with unresectable hepatocellular carcinoma (HCC) were investigated. The Tc SPECT/CT data, obtained from Tc-MAA-based treatment simulation prior to Y SIRT, were scaled with the administered Y therapy activity. 3D absorbed dose images were generated by dose kernel convolution with scaled Tc/Y SPECT/CT, Y BRS SPECT/CT, and Y PET/CT data of each patient. Absorbed dose estimates in tumor and healthy liver tissue obtained using the two SPECT/CT methods were compared against Y PET/CT.
The percentage deviation of tumor absorbed dose estimates from Y PET/CT values was on average -2 ± 18% for scaled Tc/Y SPECT/CT, whereas estimates from Y BRS SPECT/CT differed on average by -50 ± 13%. For healthy liver absorbed dose estimates, all three imaging methods revealed comparable values.
The quantification capabilities of the imaging data influence Y SIRT tumor dosimetry, while healthy liver absorbed dose values were comparable for all investigated imaging data. When no Y PET/CT image data are available, the proposed scaled Tc/Y SPECT/CT dosimetry method was found to be more appropriate for HCC tumor dosimetry than Y BRS SPECT/CT based dosimetry.
为提高钇-90 选择性内放射治疗（Y SIRT）的治疗效果，需要进行患者特异性的治疗后剂量测定。为此，已报道了基于不同可用成像数据的各种剂量测定方法。本研究的目的是比较使用锝-99m（Tc）MAA SPECT/CT、钇-90（Y）轫致辐射（BRS）SPECT/CT 和 Y PET/CT 获得的治疗后三维吸收剂量图像。
对 9 例不可切除肝细胞癌（HCC）患者的 10 次 SIRT 治疗进行了研究。从 Y SIRT 之前基于 Tc-MAA 的治疗模拟中获得的 Tc SPECT/CT 数据，根据给予的 Y 治疗活度进行缩放。通过对每位患者的缩放后的 Tc/Y SPECT/CT、Y BRS SPECT/CT 和 Y PET/CT 数据进行剂量核卷积，生成三维吸收剂量图像。将使用两种 SPECT/CT 方法获得的肿瘤和健康肝组织中的吸收剂量估计值与 Y PET/CT 进行比较。
对于缩放后的 Tc/Y SPECT/CT，肿瘤吸收剂量估计值与 Y PET/CT 值的平均百分比偏差为-2±18%，而 Y BRS SPECT/CT 的估计值平均相差-50±13%。对于健康肝脏吸收剂量估计值，所有三种成像方法显示出可比的值。
成像数据的定量能力影响 Y SIRT 肿瘤剂量测定，而所有研究的成像数据的健康肝脏吸收剂量值具有可比性。当没有 Y PET/CT 图像数据时，发现所提出的缩放后的 Tc/Y SPECT/CT 剂量测定方法比基于 Y BRS SPECT/CT 的剂量测定方法更适合 HCC 肿瘤剂量测定。
