RT Journal Article SR Electronic T1 Preoperative 123I/99mTc-Sestamibi Subtraction SPECT and SPECT/CT in Primary Hyperparathyroidism JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 2012 OP 2017 DO 10.2967/jnumed.108.054858 VO 49 IS 12 A1 Neumann, Donald R. A1 Obuchowski, Nancy A. A1 DiFilippo, Frank P. YR 2008 UL http://jnm.snmjournals.org/content/49/12/2012.abstract AB The trend toward focused surgical parathyroidectomy requires precise preoperative localization of parathyroid lesions in patients with hyperparathyroidism. The purpose of this study was to directly compare the diagnostic accuracy of 99mTc-sestamibi/123I subtraction SPECT with SPECT/CT for the localization of abnormal parathyroid glands in patients with primary hyperparathyroidism. Methods: A total of 61 consecutive surgical patients with primary hyperparathyroidism underwent both 123I/99mTc-sestamibi subtraction SPECT and SPECT/CT scans preoperatively, using a hybrid SPECT/CT instrument that combined a dual-detector SPECT camera with a 6-slice multidetector spiral CT scanner. Four hours after being given 123I-sodium iodide orally, each patient received 99mTc-sestamibi intravenously, followed immediately by a simultaneous, dual-isotope SPECT scan of the neck and upper chest. Then, without moving the patient, we performed a non–contrast-enhanced CT scan of the same body region. Normalization and subtraction of the 123I SPECT images from the 99mTc SPECT images were performed. The subtraction SPECT and the coregistered fused SPECT/CT studies were interpreted separately, with images scored on a 5-point scale. Surgical and histopathologic findings were used as the standard of comparison. Results: Surgery was successful in 57 patients (solitary parathyroid adenoma in 48 patients, double parathyroid adenomas in 6 patients, and 10 hyperplastic parathyroid glands in 3 patients). The sensitivities of SPECT (50/70 = 71%) and SPECT/CT (49/70 = 70%) were similar (P = 0.779). The specificity of SPECT/CT (26/27 = 96%) was significantly greater than that of SPECT (13/27 = 48%; P = 0.006). The receiver-operating-characteristic area under the curve of SPECT/CT (0.833) was significantly greater than that of SPECT (0.632; P < 0.001). Conclusion: SPECT/CT is significantly more specific than dual-isotope subtraction SPECT for the preoperative identification of parathyroid lesions in patients with primary hyperparathyroidism.