Dual-tracer subtraction scintigraphy combined with SPECT/CT in preoperative patients with primary hyperparathyroidism

Introduction: Hyperparathyroidism is an endocrine disorder caused by overproduction of parathyroid hormone secreted from the parathyroid glands. Although this disorder is associated with a plethora of symptoms, the majority of people are now asymptomatic and discovered during routine laboratory screening. Aim: The study presents the diagnostic accuracy of our dual tracer subtraction parathyroid scintigraphy combined with SPECT/CT imaging protocol. Materials and methods: A retrospective study was conducted between June 1st, 2021, and June 1st, 2023. A cohort of 30 patients – 29 women (96.7%) and 1 man (3.3%), aged 37 to 86 years (mean: 61.2, standard deviation: 11.6) with clinical suspicion for primary hyperparathyroidism underwent parathyroid imaging for preoperative localization of parathyroid adenoma or ectopic parathyroid gland. Results: Twenty-six out of the thirty patients with primary hyperparathyroidism had positive scan results, while four patients had negative results. The results showed adenoma of the inferior parathyroid glands in 18 patients. Adenoma of the superior parathyroid glands was found in 3 patients. Ectopic parathyroid gland was found in 4 patients. In one patient multiglandular parathyroid involvement was observed. Planar scintigraphy was positive for presence of hyperfunctioning parathyroid in 15 patients (50%), whereas SPECT/CT imaging was positive in 26 patients (86.7%) and negative in 4 patients (13.3%). Conclusions: The combination of functional and morphological data obtained from a single examination through dual-radiopharmaceutical subtraction imaging and SPECT/CT allows increased diagnostic accuracy, which influences the choice of surgical technique and treatment result.