Comparison of Planar Imaging Using Dual-phase Tc-99m-sestamibi Scintigraphy and Single Photon Emission Computed Tomography/ Computed Tomography in Hyperparathyroidism

Abstract

Objectives: The aim of this study was to compare Technetium-99m (Tc-99m)-sestamibi dual-phase planar imaging method and delayed phase single photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with primary hyperparathyroidism and to evaluate the accuracy of scintigraphy with histopathological results. Methods: Thirty-six patients with a prediagnosis of hyperparathyroidism, who had not been operated on the neck region before, and were not followed up for any other malignancy, and has confirmed histopathologic and biochemical diagnosis after parathyroidectomy, were retrospectively scanned and included in the study. The images of 36 patients who underwent dual-phase Tc-99m-sestamibi planar scintigraphy at the 20 th and 120 th minutes in the nuclear medicine clinic and delayed phase SPECT/CT imaging immediately after the 120 th minute planar imaging were evaluated visually by two nuclear medicine specialists as positive or negative lesion. Dual-phase planar and SPECT/CT images were statistically compared in terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Results: Thirty-six patients with 41 lesions were evaluated. Comparing dual-phase planar imaging and delayed phase SPECT/CT revealed, sensitivity 84.21%-94.74%, specificity 66.67%-66.67%. Positive predictive value 96.97%-97.30%, negative predictive value 25%-50.0%, accuracy 82.93%-92.68% respectively. There was a statistically significant difference between planar imaging and SPECT/CT; SPECT/CT localized the lesion more accurately (p<0.05). Conclusion: SPECT/CT is superior to planar imaging in determining the anatomical details and localization of the lesion, especially in determining the depth of the lesions in the neck and whether it is ectopic. In patients with hyperparathyroidism, SPECT/CT should be used routinely to detect parathyroid pathologies because it has a lower rate of error and higher accuracy rate.

Pitfalls of DualTracer 99m-Technetium (Tc) Pertechnetate and Sestamibi Scintigraphy before Parathyroidectomy: Between Primary-Hyperparathyroidism-Associated Parathyroid Tumour and Ectopic Thyroid Tissue

“…99m-Tc scintigraphy represents a key imaging tool to address the parathyroid glands and, in most countries, almost every patient that is referred to parathyroidectomy had underwent at least one imaging procedure before surgery, mostly ultrasound in addition to 99m-Tc sestamibi scintigraphy [8,9]. Moreover, the results may be enhanced by adding SPECT (single-photon-emission computed tomography) or SPECT/CT regardless of an orthotopic or ectopic parathyroid tumour [10,11]. The underlying pathway of this molecular imaging is represented by the detection of the mitochondrial content at the level of parathyroid tissue, noting that hyper-functional parathyroid glands in PHP are associated with a high-oxyphil-cell-related abundant mitochondrial count [12,13].…”

“…The molecular imaging approach brings more functional information when compared to structural (standard) techniques such as CT or MRI. Further on, PET/CT (positron emission tomography), for instance, with 18 F-Fluorocholine or 11 C-methionine and PET/MRI (which requires lower radiation dose than PET/CT or CT scan), provides useful dynamic captures [7,14,15]. Additionally, angiographic selective venous sampling represents an alternative to the multimodal diagnosis approaches in the parathyroid field, but its exact placement among other modalities currently represents an emergent issue to be solved [16,17].…”