Strong correlation has been demonstrated between tumor dose and response and between healthy liver dose and side effects. Individualized dosimetry is increasingly recommended in the current clinical routine. However, hepatic and tumor segmentations could be complex in some cases. The aim of this study is to assess the reproducibility of the tumoral and non-tumoral liver dosimetry in selective internal radiation therapy (SIRT). Twenty-three patients with hepatocellular carcinoma (HCC) who underwent SIRT with glass microspheres were retrospectively included in the study. Tumor (TV) and total liver volumes (TLV), and mean absorbed doses in tumoral liver (TD) and non-tumoral liver (THLD) were determined on the 90Y PET/CT studies using Simplicit90YTM software, by three independent observers. Dosimetry datasets were obtained by a medical physicist helped by a nuclear medicine (NM) physician with 10 years of experience (A), by a NM physician with 4-year experience (B), and by a resident who first performed 10 dosimetry assessments as a training (C). Inter-observer agreement was evaluated using intra-class correlation coefficients (ICC), coefficients of variation (CV), Bland-Altman plots, and reproducibility coefficient (RDC). A strong agreement was observed between all three readers for estimating TLV (ICC 0.98) and THLD (ICC 0.97). Agreement was lower for TV delineation (ICC 0.94) and particularly for TD (ICC 0.73), especially for the highest values. Regarding TD, the CV (%) was 26.5, 26.9, and 20.2 between observers A and B, A and C, and B and C, respectively, and the RDC was 1.5. Regarding THLD, it was 8.5, 12.7, and 9.4, and the RDC was 1.3. Using a standardized methodology, and regardless of the different experiences of the observers, the estimation of THLD is highly reproducible. Although the reproducibility of the assessment of tumor irradiation is overall quite high, large variations may be observed in a limited number of patients.

中文翻译：

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玻璃微球经动脉放射栓塞后肝细胞癌中90Y PET / CT剂量测定的观察者间差异。

已经证明在肿瘤剂量和反应之间以及健康肝剂量和副作用之间有很强的相关性。在当前的临床常规中，越来越多地推荐个体化剂量测定法。但是，在某些情况下，肝和肿瘤的分割可能很复杂。这项研究的目的是评估选择性内部放射治疗（SIRT）中肿瘤和非肿瘤肝剂量的可重复性。本研究回顾性纳入了23例行玻璃微球SIRT治疗的肝细胞癌（HCC）患者。在90Y PET / CT研究中，使用Simplicit90YTM软件，由三个独立的观察者确定了肿瘤（TV）和总肝体积（TLV），以及在肿瘤肝（TD）和非肿瘤肝（THLD）中的平均吸收剂量。剂量学数据集是由具有10年经验的核医学（NM）医师（A），具有4年经验的NM医师（B）以及首先进行10次剂量学评估的居民协助的医学物理学家获得的。训练（C）。使用组内相关系数（ICC），变异系数（CV），Bland-Altman图和再现性系数（RDC）评估观察者之间的一致性。三位读者在估算TLV（ICC 0.98）和THLD（ICC 0.97）方面均达成了强烈共识。电视定界（ICC 0.94），尤其是TD（ICC 0.73），尤其是最高值的一致性较低。关于TD，观察者A和B，A和C，B和C的CV（％）分别为26.5、26.9和20.2，RDC为1.5。关于THLD，分别为8.5、12.7和9.4，而RDC为1.3。使用标准化的方法，并且不管观察者的不同经验如何，THLD的估计都是高度可重复的。尽管总体上评估肿瘤照射的可重复性很高，但是在有限数量的患者中可能会观察到很大的差异。