Differences in quantitative 99mTc-MIBI SPECT/CT parameters between parathyroid adenoma and hyperplasia in secondary hyperparathyroidism.

OBJECTIVE

The aim of this retrospective study was to investigate the differences in early- and delayed-phase maximum standardized uptake value (SUVmax) and lesion volume on 99mTc-sestamibi (99mTc-MIBI) SPECT/CT between parathyroid adenoma (PA) and parathyroid hyperplasia (PH) in patients with secondary hyperparathyroidism (SHPT).

MATERIALS AND

METHODS

A total of 111 patients with stage 5 chronic kidney disease (CKD5) undergoing hemodialysis were enrolled in this study. All patients underwent preoperative 99mTc-MIBI SPECT/CT scintigraphy for the detection and localization of parathyroid lesions. Quantitative SPECT/CT was performed after planar imaging, and the SUVmax and volume of each positive parathyroid lesions were measured on SPECT/CT. Linear mixed-effects models accounting for within-patient clustering were used to compare parameters between PA and PH, with further adjustment for lesion volume. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the discriminative ability of these parameters.

RESULTS

After adjustment for within-patient clustering, PA lesions showed significantly higher early-phase SUVmax (β = 1.473, P < 0.001), delayed-phase SUVmax (β = 0.745, P < 0.001), and lesion volume (β = 0.571, P < 0.001) than PH lesions. After further adjustment for lesion volume, the difference in early-phase SUVmax remained significant (β = 0.542, P = 0.034), whereas the difference in delayed-phase SUVmax was no longer significant (P = 0.404). Lesion volume was strongly associated with both early- and delayed-phase SUVmax (both P < 0.001). A ROC curve analysis showed that the area under the curve (AUC) for early-phase SUVmax and lesion volume was 0.612 and 0.621, respectively, for distinguishing PA from PH.

CONCLUSION

Lesion volume is a major determinant of 99mTc-MIBI uptake in SHPT, while early-phase SUVmax remains independently different after adjustment for volume. When combined with clinical presentation and other examinations, early-phase SUVmax may provide complementary biological information for graft selection.