Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
Duke University School of Medicine, Durham, NC, USA.
Abdom Radiol (NY). 2021 Jul;46(7):3301-3308. doi: 10.1007/s00261-021-02999-9. Epub 2021 Mar 10.
To assess differences in FDG-PET/CT uptake among four subtypes of renal tumors: clear cell RCC (ccRCC), papillary type I and II RCC (pRCC), and oncocytoma.
This retrospective study investigated 33 patients with 98 hereditary renal tumors. Lesions greater than 1 cm and patients with a timeframe of less than 18 months between preoperative imaging and surgery were considered. FDG-PET/CT images were independently reviewed by two nuclear medicine physicians, blinded to clinical information. Volumetric lesion SUV was measured and used to calculate a target-to-background ratio respective to liver (TBR). The Shrout-Fleiss intra-class correlation coefficient was used to assess reliability between readers. A linear mixed effects model, accounting for within-patient correlations, was used to compare TBR values of primary renal lesions with and without distant metastasis.
The time interval between imaging and surgery for all tumors had a median of 77 (Mean: 139; Range: 1-512) days. Intra-class reliability of mean TBR resulted in a mean κ score of 0.93, indicating strong agreement between the readers. The mixed model showed a significant difference in mean TBR among the subtypes (p < 0.0001). Pairwise comparison showed significant differences between pRCC type II and ccRCC (p < 0.0001), pRCC type II and pRCC type I (p = 0.0001), and pRCC type II and oncocytoma (p = 0.0016). Furthermore, a significant difference in FDG uptake was present between primary pRCC type II renal lesions with and without distant metastasis (p = 0.023).
pRCC type II lesions demonstrated significantly higher FDG activity than ccRCC, pRCC type I, or oncocytoma. These findings indicate that FDG may prove useful in studying the metabolic activity of renal neoplasms, identifying lesions of highest clinical concern, and ultimately optimizing active surveillance, and personalizing management plans.
评估四种肾肿瘤亚型（透明细胞肾细胞癌[ccRCC]、Ⅰ型和Ⅱ型乳头状肾细胞癌[pRCC]和嗜酸细胞瘤）中 FDG-PET/CT 摄取的差异。
本回顾性研究纳入了 33 名患有 98 个遗传性肾肿瘤的患者。研究对象为病灶大于 1cm 且术前影像学检查与手术之间的时间间隔小于 18 个月的患者。FDG-PET/CT 图像由两名核医学医师独立进行评估，评估过程中两位医师均不了解临床信息。测量病变的容积 SUV，并计算与肝脏的靶标与背景比（TBR）。采用 Shout-Fleiss 组内相关系数评估两位读者间的可靠性。采用线性混合效应模型，考虑到患者内相关性，比较有和无远处转移的原发性肾肿瘤的 TBR 值。
所有肿瘤的影像学检查与手术之间的时间间隔中位数为 77（均值：139；范围：1-512）天。平均 TBR 的组内可靠性导致读者间的平均κ评分为 0.93，表明两者间具有很强的一致性。混合模型显示各亚型之间的平均 TBR 存在显著差异（p<0.0001）。两两比较显示，Ⅱ型 pRCC 与 ccRCC（p<0.0001）、Ⅱ型 pRCC 与Ⅰ型 pRCC（p=0.0001）、Ⅱ型 pRCC 与嗜酸细胞瘤（p=0.0016）之间的 TBR 差异具有统计学意义。此外，原发性Ⅱ型 pRCC 肾肿瘤有和无远处转移之间的 FDG 摄取存在显著差异（p=0.023）。
Ⅱ型 pRCC 病变的 FDG 活性明显高于 ccRCC、Ⅰ型 pRCC 或嗜酸细胞瘤。这些发现表明，FDG 可能有助于研究肾肿瘤的代谢活性，识别最具临床关注的病变，并最终优化主动监测和个性化管理计划。
