ABSTRACT
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 99m Tc-Sestamibi SPECT/CT scan in nPHTP compared with classical hypercalcemic PHPT (cPHPT). MATERIALS AND METHODS: We retrospectively studied 125 patients with 99m Tc-Sestamibi SPECT/CT scans. Subjects were divided into 2 groups: cPHPT (n = 93) and nPHPT (n = 32). RESULTS: The detection rate of 99m Tc-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 99m Tc-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 18 F-Choline PET/CT when the clinical context justifies it.
Subject(s)
Hypercalcemia , Hyperparathyroidism, Primary , Humans , Hyperparathyroidism, Primary/diagnostic imaging , Parathyroid Glands/diagnostic imaging , Positron Emission Tomography Computed Tomography/methods , Retrospective Studies , Technetium Tc 99m Sestamibi , Tomography, Emission-Computed, Single-PhotonABSTRACT
El hiperparatiroidismo persistente/recurrente representa un desafío en la localización del tejido paratiroideo hiperfuncionante. En esta subpoblación, los métodos convencionales ofrecen un menor rédito diagnóstico. La 18F-colina PET/TC podría ser una buena alternativa dada su mejor resolución espacial, capacidad de detectar glándulas ectópicas y la conjunción de la imagen molecular y anatómica. Sin embargo, la evidencia en este subgrupo de pacientes es escasa. Objetivo: evaluar la utilidad de la 18F-colina PET/TC como método de localización en el hiperparatiroidismo persistente o recurrente. Materiales y métodos: se analizaron los pacientes con 18F-colina PET/TC para hiperparatiroidismo entre diciembre de 2015 y enero de 2018 en un centro terciario de alto volumen. Se analizaron el número de lesiones, su localización, tamaño y el Standard Uptake Value máximo (SUV max) en las imágenes tempranas y tardías. Se compararon los resultados con los métodos convencionales. Resultados: 7 de 15 pacientes habían sido operados previamente (persistentes/recurrentes). La 18F-colina PET/TC detectó 6/7 casos (83,33%), la ecografía cervical 1/4 (25%) y el SPECT de paratiroides y la resonancia nuclear magnética 2/5 (40%). El SUV max obtenido fue variable, en la mitad de los casos a los 10 minutos y en los restantes a la hora; el tamaño promedio de las lesiones fue 8,61 mm (6-12 mm). Conclusiones: la 18F-colina PET/TC muestra una alta tasa de detección en los pacientes con hiperparatiroidismo persistente/recurrente. La combinación del comportamiento biológico del PET con los hallazgos morfológicos aportados por la TC con contraste endovenoso le ofrecería ventajas sobre otros estudios que podrían posicionarlo como método de primera línea en esta subpoblación. (AU)
Persistent or recurrent hyperparathyroidism represents a challenge regarding the localization of the hyper-functioning parathyroid tissue. In this subpopulation of hyperpharathyroid patients, conventional methods have a low diagnostic yield. The 18F-choline PET /CT could be a good alternative given its better spatial resolution, ability to detect ectopic glands, and the conjunction of the molecular and anatomical image. However, the evidence in this subgroup of patients is limited. Objective: to evaluate the utility of 18F-choline PET/ CT as a localization method in persistent or recurrent hyperparathyroidism. Materials and methods: patients with 18F-choline PET / CT for hyperparathyroidism between December 2015 and January 2018 in a high-volume tertiary center were included. The number of lesions, and their location, size, and maximum Standard Uptake Value (SUV) in the early and late images were analyzed. The results were compared to conventional methods. Results: 7 of 15 patients had been previously operated (persistent/recurrent). 18F-choline PET / CT detected 6/7 cases (83,33%), cervical ultrasound 1/4 (25%) and parathyroid SPECT and magnetic resonance 2/5 (40%). The maximum SUV was variable, one half at 10 minutes and the other half at 60 minutes; the average size of the lesions was 8.61 mm (6-12 mm). Conclusions: 18F-Choline PET / CT shows a high detection rate in patients with persistent / recurrent hyperparathyroidism. The combination of the biological behavior of PET with the morphological findings provided by CT with intravenous contrast would offer advantages over other studies that could position it as a first line method in this subpopulation. (AU)