Standardized uptake values and ratios on 68Ga-DOTATATE PET-computed tomography for normal organs and malignant lesions and their correlation with Krenning score in patients with metastatic neuroendocrine tumors

The aim was to estimate the physiological standardized uptake values (SUVs) on 68Ga-DOTATATE PET-computed tomography (CT) in normal organs and metastatic tumor lesions (both standard and delayed), and correlating the uptake values and ratios with Krenning Scores (K-score) in patients with metastatic/advanced neuroendocrine tumors (NETs) undergoing PET-CT studies for their management work-up. A total of 32 patients of metastatic NET with 95 discrete tumor lesions were included in this analysis. These patients underwent standard whole-body PET-CT following injection of 2–3 mCi (74–111 MBq) of 68Ga-DOTATATE at 1–1.5 h. The normal physiological SUVmean of the liver and spleen and SUVmax and SUVmean of tumor lesions were estimated by an in-built automated procedure. These patients also underwent a delayed scan (2.5–3 h) and the same parameters were obtained for the delayed study. The tumorous lesions were further classified on the basis of K-score, and this was correlated with the mean SUVmax on both early and delayed scans. SUVmean ratios (tumor-to-liver and tumor-to-spleen) were also calculated for both time-points and correlated with individual K-scores. In lesions with K-score 4, the mean SUVmax was 32.5 in early and 30.5 in delayed scan, for lesions with K-score of 3 and 2, the mean SUVmax were 17.3, 20, and 9.3, 9.2, respectively, while in K-score 1 (n = 1), the delayed mean SUVmax was found to be more than early mean SUVmax (3.2 to 2.3). Statistical sign...
Source: Nuclear Medicine Communications - Category: Nuclear Medicine Tags: Technical Notes Source Type: research