Beyond conventional maging: the diagnostic performance of [⁶⁸Ga]Ga-Trivehexin PET/CT for detecting hyperfunctioning...

The aim of this study was to evaluate the diagnostic performance and lesion localization capability of [⁶⁸Ga]Ga-Trivehexin PET/CT for hyperfunctioning parathyroid tissue in primary hyperparathyroidism (P-HPT), through a retrospective analysis of data obtained from prospective studies conducted at two different centres, compared with the conventional preoperative imaging modalities [⁹⁹ᵐTc]Tc-MIBI scintigraphy and neck ultrasonography (US).

A total of 44 patients diagnosed with P-HPT based on clinical and laboratory parameters, who subsequently underwent cervical ultrasonographic evaluation, were included in this study. For all patients, serum parathyroid hormone (PTH), calcium (Ca), phosphorus (P), 25-OH vitamin D, urea, creatinine, glomerular filtration rate (GFR), and 24-hour urinary calcium values were recorded. Following cervical US examination, all participants underwent [⁹⁹ᵐTc]Tc-MIBI scintigraphy as part of the routine preoperative work-up. Thereafter, to determine the diagnosis and localization of hyperfunctioning parathyroid tissue, [⁶⁸Ga]Ga-Trivehexin PET/CT imaging was performed. All [⁶⁸Ga]Ga-Trivehexin PET/CT data were visually assessed and quantitative measurements were obtained. [⁶⁸Ga]Ga-Trivehexin PET/CT findings were evaluated in conjunction with PTH wash-out results, postoperative biochemical response confirmation, and histopathological assessment.

Forty-four patients with P-HPT (median age, 52 years; range, 24-73) were included. [⁶⁸Ga]Ga-Trivehexin PET/CT identified 37 hyperfunctioning parathyroid foci in 36 patients, corresponding to a patient-based detection rate of 81.8% (36/44). US and [⁹⁹ᵐTc]Tc-MIBI scintigraphy detected lesions in 45.5% (20/44) and 47.7% (21/44) of patients, respectively, while in the 4D-CT subgroup (n = 20), a lesion was detected in 13 patients. Among 23 [⁹⁹ᵐTc]Tc-MIBI-negative patients, [⁶⁸Ga]Ga-Trivehexin PET/CT demonstrated at least one positive focus in 18, and on a lesion-based analysis, [⁶⁸Ga]Ga-Trivehexin PET/CT confirmed 19 of 22 [⁹⁹ᵐTc]Tc-MIBI -positive lesions while revealing additional foci in [⁹⁹ᵐTc]Tc-MIBI-negative patients. According to the composite reference standard, [⁶⁸Ga]Ga-Trivehexin PET/CT achieved a sensitivity of 97.3% and a PPV of 100%, clearly outperforming [⁹⁹ᵐTc]Tc-MIBI scintigraphy and US.

In patients with primary hyperparathyroidism, [⁶⁸Ga]Ga-Trivehexin PET/CT demonstrated significantly higher sensitivity than currently used standard imaging modalities. These findings suggest that [⁶⁸Ga]Ga-Trivehexin PET/CT represents a promising diagnostic alternative, particularly in cases where conventional imaging is negative or inconclusive.