Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
Nuclear Medicine Department, Eugene Marquis Center, Rennes, France.
Eur J Nucl Med Mol Imaging. 2023 Dec;51(1):245-257. doi: 10.1007/s00259-023-06416-9. Epub 2023 Sep 12.
Investigate reproducibility of two segmentation methods for multicompartment dosimetry, including normal tissue absorbed dose (NTAD) and tumour absorbed dose (TAD), in hepatocellular carcinoma patients treated with yttrium-90 (Y) glass microspheres.
TARGET was a retrospective investigation in 209 patients with < 10 tumours per lobe and at least one tumour ≥ 3 cm ± portal vein thrombosis. Dosimetry was compared using two distinct segmentation methods: anatomic (CT/MRI-based) and count threshold-based on pre-procedural Tc-MAA SPECT. In a round robin substudy in 20 patients with ≤ 5 unilobar tumours, the inter-observer reproducibility of eight reviewers was evaluated by computing reproducibility coefficient (RDC) of volume and absorbed dose for whole liver, whole liver normal tissue, perfused normal tissue, perfused liver, total perfused tumour, and target lesion. Intra-observer reproducibility was based on second assessments in 10 patients ≥ 2 weeks later.
Tc-MAA segmentation calculated higher absorbed doses compared to anatomic segmentation (n = 209), 43.9% higher for TAD (95% limits of agreement [LoA]: - 49.0%, 306.2%) and 21.3% for NTAD (95% LoA: - 67.6%, 354.0%). For the round robin substudy (n = 20), inter-observer reproducibility was better for anatomic (RDC range: 1.17 to 3.53) than Tc-MAA SPECT segmentation (1.29 to 7.00) and similar between anatomic imaging modalities (CT: 1.09 to 3.56; MRI: 1.24 to 3.50). Inter-observer reproducibility was better for larger volumes. Perfused normal tissue volume RDC was 1.95 by anatomic and 3.19 by Tc-MAA SPECT, with corresponding absorbed dose RDC 1.46 and 1.75. Total perfused tumour volume RDC was higher, 2.92 for anatomic and 7.0 by Tc-MAA SPECT with corresponding absorbed dose RDC of 1.84 and 2.78. Intra-observer variability was lower for perfused NTAD (range: 14.3 to 19.7 Gy) than total perfused TAD (range: 42.8 to 121.4 Gy).
Anatomic segmentation-based dosimetry, versus Tc-MAA segmentation, results in lower absorbed doses with superior reproducibility. Higher volume compartments, such as normal tissue versus tumour, exhibit improved reproducibility.
NCT03295006.
研究钇-90（Y）玻璃微球治疗肝细胞癌患者时两种多腔室剂量测定方法（包括正常组织吸收剂量[NTAD]和肿瘤吸收剂量[TAD]）的可重复性。
TARGET 是一项回顾性研究，纳入了每个肝叶肿瘤数少于 10 个且至少有一个肿瘤≥3cm±门静脉血栓的 209 例患者。使用两种不同的分割方法进行剂量比较：基于 CT/MRI 的解剖学分割和基于术前 Tc-MAA SPECT 的计数阈值分割。在 20 例≤5 个单叶肿瘤的患者中进行了一轮重复性研究，8 名观察者的可重复性通过计算全肝、全肝正常组织、灌注正常组织、灌注肝、总灌注肿瘤和靶病变的体积和吸收剂量的可重复性系数（RDC）进行评估。在 10 例≥2 周后进行第二次评估的患者中评估了观察者内的可重复性。
Tc-MAA 分割计算的吸收剂量高于解剖学分割（n=209），TAD 高 43.9%（95%置信区间[LoA]：-49.0%，306.2%），NTAD 高 21.3%（95% LoA：-67.6%，354.0%）。对于重复性研究（n=20），解剖学分割的观察者间可重复性优于 Tc-MAA SPECT 分割（RDC 范围：1.17-3.53），与解剖学成像方式（CT：1.09-3.56；MRI：1.24-3.50）相似。体积较大时，观察者间的可重复性更好。解剖学 RDC 为 1.95，Tc-MAA SPECT 为 3.19，相应的吸收剂量 RDC 为 1.46 和 1.75。总灌注肿瘤体积 RDC 更高，解剖学为 2.92，Tc-MAA SPECT 为 7.0，相应的吸收剂量 RDC 为 1.84 和 2.78。与总灌注 TAD（范围：42.8-121.4 Gy）相比，灌注 NTAD（范围：14.3-19.7 Gy）的观察者内变异性较低。
与 Tc-MAA 分割相比，基于解剖学分割的剂量测定结果吸收剂量较低，可重复性更高。体积较大的正常组织与肿瘤等容积区域，其可重复性更高。
NCT03295006。
