Department of Radiology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-Ku, Fukuoka, 814-0180, Japan.
Department of Diagnostic and Interventional Radiology, Kochi Medical School, Kochi University, Kochi, Japan.
Jpn J Radiol. 2023 May;41(5):531-540. doi: 10.1007/s11604-022-01378-8. Epub 2023 Jan 13.
We evaluated the reproducibility calculating volume-based FDG-PET/CT parameters, i.e., metabolic tumor volume (MTV) and total lesion glycolysis (TLG), in soft tissue tumors.
Fifty-three cases with soft tissue tumors were analyzed retrospectively. The conditions determining the lower limit of MTV were fixed value SUV 2.5 or 30% of SUVmax. To investigate the agreement of the measurements by two radiologists, %difference, the correlation coefficients and Bland-Altman plot were analyzed. We compared these parameters in both intra- and inter-operator for evaluating the agreement in the measurements.
The values of % difference were excellent, 0.2-3.5%, in the intra-operator in all calculated volume-based parameters. In both inter- and intra-operator analysis, the values of % differences were lower in the parameters calculated by SUV 2.5 fixed value as a lower threshold compared with those calculated by 30% of SUVmax as a lower threshold. The correlation coefficient in MTV30% for inter-operator were 0.84 or 0.87, those were lower than values by the intra-operator evaluation. Nevertheless, the correlation coefficients were higher than 0.84 in every parameter. Particularly, correlation coefficient in the parameters calculated by SUV 2.5 fixed value was better than those calculated by 30% of SUVmax. The Bland-Altman plot analysis showed good agreement for all parameters, particularly in the intra-operator examinations. However, in the inter-operator study, some variances were noted in every condition.
In conclusion, the reproducibility of measuring volume-based FDG-PET/CT parameters of soft tissue tumors was good, particularly, in the measurement by fixed lower limit value SUV 2.5 in the intra-operator.
我们评估了基于体积的 FDG-PET/CT 参数（即代谢肿瘤体积[MTV]和总病灶糖酵解[TLG]）在软组织肿瘤中的可重复性。
回顾性分析了 53 例软组织肿瘤患者。固定 SUV 值 2.5 或 SUVmax 的 30%作为 MTV 的下限条件来确定下限条件。为了研究两位放射科医生测量结果的一致性，分析了差异百分比、相关系数和 Bland-Altman 图。我们比较了这两个参数的测量结果，以评估测量结果的一致性。
在所有基于体积的参数中，在内部操作者的测量中，差异百分比的值为 0.2-3.5%，为优秀。在内部和外部操作者分析中，与 SUVmax 的 30%作为下限相比，以 SUV 2.5 固定值作为下限计算的参数的差异百分比值较低。在 30%SUV 间操作者的 MTV30%的相关系数为 0.84 或 0.87，这些值低于内部操作者的评估值。然而，每个参数的相关系数均高于 0.84。特别是，以 SUV 2.5 固定值计算的参数的相关系数优于以 SUVmax 的 30%计算的参数。Bland-Altman 图分析显示，所有参数的一致性良好，特别是在内部操作者的检查中。然而，在外部操作者的研究中，在每种情况下都注意到了一些差异。
总之，在软组织肿瘤中，基于体积的 FDG-PET/CT 参数的可重复性较好，特别是在内部操作者中使用固定的下限值 SUV 2.5 进行测量时。
