Quantitative and comparative assessment of Tc-99 m MIBI imaging in parathyroid adenomas: associations with biochemical, morphological, and histopathological

Purpose To investigate the relationships between Tc-99 m methoxyisobutylisonitrile (MIBI) SPECT/CT-derived SUVmax values and adenoma volume, histopathological characteristics, and biochemical parameters in patients with primary hyperparathyroidism (PHPT), and to compare the localization performance of ultrasonography (USG), planar scintigraphy, pinhole imaging, and SPECT/CT.Methods Sixty patients with histopathologically confirmed solitary parathyroid adenomas who underwent preoperative Tc-99 m MIBI scintigraphy and subsequent surgery were retrospectively included. SUVmax values were obtained from quantitative SPECT/CT images using manually defined volumetric regions of interest. Associations between SUVmax and continuous clinicopathological variables were evaluated using Spearman correlation analysis, while comparisons among predominant cell-type groups were performed using the Kruskal-Wallis test. Detection rates of the imaging modalities were compared using Cochran's Q test.Results SUVmax demonstrated significant positive correlations with adenoma volume (ρ = 0.523, p Conclusion Tc-99 m MIBI SPECT/CT-derived SUVmax was significantly associated with adenoma volume in patients with PHPT. Oxyphil-predominant adenomas showed numerically higher SUVmax values, although differences among cellular subtypes were not statistically significant. Scintigraphic techniques provided complementary localization information in lesions not identified by ultrasonography. The clinical utility of quantitative SPECT/CT and its potential relationships with histopathological characteristics require further validation in larger prospective studies.