Normocalcemic primary hyperparathyroidism: 99mTc SestaMibi SPECT/CT results compare with hypercalcemic hyperparathyroidism

• Published in: Clinical endocrinology (Oxford) Vol. 96; no. 6; pp. 831 - 836
• Main Authors: Musumeci, Martina, Pereira, Lucía Valeria, San Miguel, Lucas, Cianciarelli, Constanza, Vazquez, Eliana Cecilia, Mollerach, Ana María, Arma, Irene Josefa, Hume, Isabel, Galich, Ana María, Collaud, Carlos
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2022
• Subjects: Calcium (blood); Computed tomography; Humans; Hypercalcemia; hypercalcemic hyperparathyroidism; Hyperparathyroidism; Hyperparathyroidism, Primary - diagnostic imaging; Localization; Medical imaging; normocalcemic hyperparathyroidism; Parathyroid; Parathyroid Glands - diagnostic imaging; Parathyroid hormone; parathyroid scintigraphy; Patients; Positron Emission Tomography Computed Tomography - methods; Retrospective Studies; Single photon emission computed tomography; SPECT/CT; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Ultrasonic imaging; hypercalcemic hyperparathyroidism; normocalcemic hyperparathyroidism; SPECT/CT; parathyroid scintigraphy
• ISSN: 0300-0664; 1365-2265; 1365-2265
• DOI: 10.1111/cen.14667

Context Normocalcemic primary hyperparathyroidism (nPHPT) is defined by an inappropriately increased serum PTH with normal serum calcium. Information about the diagnostic yield of parathyroid SPECT/CT scan and ultrasonography in nHPPT is limited and not conclusive. Purpose To evaluate the positivity rate of 99mTc‐Sestamibi SPECT/CT scan in nPHTP compared with classical hypercalcemic PHPT (cPHPT). Materials and Methods We retrospectively studied 125 patients with 99mTc‐Sestamibi SPECT/CT scans. Subjects were divided into 2 groups: cPHPT (n = 93) and nPHPT (n = 32). Results The detection rate of 99mTc‐Sestamibi SPECT/CT in cPHPT was 86,02% (80/93) and 59.37%, in nPHPT (19/32), p = .003. No significant differences were seen between the SPECT/CT scan and ultrasonography (p = .28) and the agreement was higher in cPHPT than in nPHPT, p = .03. Sensitivity of 99m Tc‐Sestamibi‐SPECT/CT was 98% on a per‐patient basis (PPV 96%) and 91% on a per‐lesion basis (PPV 88%). Glandular size was smaller in nPHPT (mean value 6.8 mm) and it was related only with PTH value. Conclusion Localization rate of parathyroid hyperfunctioning tissue with 99mTc‐Sestamibi SPECT/CT is lower in nPHPT and it is related to a smaller glandular size. However, our study suggests that the positivity rate and sensitivity are nonnegligible by adding SPECT/CT. The reduction in the detection rate in nPHPT could benefit techniques with higher resolution such as 18F‐Choline PET/CT when the clinical context justifies it.