68Ga-Trivehexin PET/CT: a promising novel tracer for primary hyperparathyroidism.

Introduction: This study aims to assess ⁶⁸Ga-Trivehexin PET/CT for detecting hyperfunctioning parathyroid tissue in comparison to [^99mTc]Tc-MIBI scintigraphy-SPECT/CT (MIBI scan) in patients with primary hyperparathyroidism (PHPT).

Methods: The cohort comprised 13 patients diagnosed with PHPT based on biochemical analyses, including serum calcium, phosphorus, and parathyroid hormone (PTH) levels. Each participant underwent cervical ultrasonography, MIBI scan, and ⁶⁸Ga-Trivehexin PET/CT imaging. Complementary 4D-CT and [¹⁸F]fluorocholine PET/CT were conducted in 7 patients. Ten lesions of 7 patients underwent PTH wash-out (WO) procedure. ⁶⁸Ga-Trivehexin PET/CT findings were compared with other modalities and PTH-WO results.

Results: Ten patients had sporadic PHPT, while 3 were diagnosed with MEN-1 syndrome-associated PHPT. One patient did not have any identifiable parathyroid lesion across the imaging modalities. On a patient-based analysis, MIBI scan and ⁶⁸Ga-Trivehexin PET/CT identified parathyroid lesions in 10 and 11 patients, respectively. However, ⁶⁸Ga-Trivehexin PET/CT detected 7 additional parathyroid lesions that were negative on the MIBI scan. Consequently, 17 lesions were identified and confirmed as hyperfunctioning parathyroid tissue through imaging, PTH-WO, or a combination of both modalities. In lesion-based evaluation, ⁶⁸Ga-Trivehexin identified 16 lesions compared to 10 by MIBI scan, resulting in a detection rate of 94.1% and 58.8%, respectively. Notably, in three patients who underwent [¹⁸F]fluorocholine PET/CT, no lesions were detected; yet ⁶⁸Ga-Trivehexin PET/CT successfully identified parathyroid lesions in two of these patients.

Conclusion: Our study provides the first evidence that ⁶⁸Ga-Trivehexin PET/CT can effectively identify hyperfunctioning parathyroid tissue with a high detection rate warranting further investigations to comprehensively explore its potential in PHPT management.