Added Value of Subtraction SPECT/CT in Dual-Isotope Parathyroid Scintigraphy

Abstract

Background: Adding subtraction single-photon emission computed tomography/computed tomography (SPECT/CT) to dual isotope (I-123 and Tc-99m-sestamibi) subtraction parathyroid scintigraphy is not widely implemented. We aimed to assess the added value of dual isotope subtraction SPECT/CT over single isotope SPECT/CT as an adjunct to dual isotope planar pinhole subtraction scintigraphy. Methods: Parathyroid scintigraphies from 106 patients with an estimated total of 415 parathyroid glands who (1) were diagnosed with primary hyperparathyroidism, (2) underwent dual isotope subtraction scintigraphy in the Department of Nuclear Medicine, Gentofte Hospital, Denmark throughout 2017 and (3) underwent subsequent parathyroidectomy, were included. The original dual isotope planar pinhole subtraction plus dual isotope subtraction SPECT/CT (dual/dual method) exams were retrospectively re-evaluated using only Tc-99m-sestamibi SPECT/CT (dual/single method). Statistics were calculated per parathyroid. Surgical results confirmed by pathology served as reference standard. Results: The dual/dual method had higher sensitivity than the dual/single method (82% (95%CI 74%–88%) vs. 69% (95%CI 60%–77%)) while specificity, positive and negative predictive values (PPV and NPV) were similar (specificity 96% vs. 93%, PPV’s 87% vs. 82% and NPV’s 89% vs. 93%). Reader confidence was higher when employing the dual/dual method (p = 0.001). Conclusions: The dual/dual method can be considered superior to the dual/single method in the preoperative imaging in primary hyperparathyroidism.

11C-Choline PET/CT vs. 99mTc-MIBI/123Iodide Subtraction SPECT/CT for Preoperative Detection of Abnormal Parathyroid Glands in Primary Hyperparathyroidism: A Prospective, Single-Centre Clinical Trial in 60 Patients

“…However, dual-isotope subtraction parathyroid scintigraphy with 99m Tc-MIBI and 123 Iodide including SPECT/CT and planar pinhole imaging has a high diagnostic accuracy and is currently the most widely used method in eastern Denmark. The method has proven to be superior to both single-isotope MIBI planar and SPECT/CT imaging and to dual isotope subtraction scintigraphy with single isotope SPECT/CT [ 4 , 5 , 6 , 7 ].…”

Preoperative imaging in primary hyperparathyroidism: Are 11C‐Choline PET/CT and 99mTc‐MIBI/123Iodide subtraction SPECT/CT interchangeable or do they supplement each other?

“…One widely used method is dual-isotope subtraction parathyroid scintigraphy with 99m Tc-MIBI and 123 Iodide including SPECT/CT and planar pinhole imaging (Di-SPECT), which has a high diagnostic accuracy (sensitivity 82%-93% [5][6][7] ) and was proven superior to both singleisotope MIBI planar and SPECT/CT imaging and to dual-isotope subtraction scintigraphy with single isotope SPECT/CT (sensitivities 17%-89%). [5][6][7][8][9][10] Due to the high cost, time consumption (≤4.5 h) and radiation dose (≈13 mSv) alternative modalities such as positron emission tomography/computed tomography (PET/CT) using carbon-11-labelled choline ( 11 C-Choline) as the tracer (Choline PET) have been evaluated and found promising with sensitivity as high as 87%-97%. [11][12][13][14] Other widely used methods include 4D-CT and ultrasound, both of which have previously been found to have varying sensitivity, 55%-85% and 29%-81%, respectively.…”

Diagnostic performance of dual phase 99mTc-MIBI planar and SPECT/CT scintigraphy in primary hyperparathyroidism

“…Primary hyperparathyroidism (PHPT) is a common endocrine disorder with an estimated prevalence of about 0.23% among females and 0.085% among males; it is caused by abnormal increased secretion of parathyroid hormone, resulting in hypercalcemia. This disease is attributed in most of the cases (80-85%) to solitary parathyroid adenoma, followed by glandular hyperplasia in 10-15% of the cases, and double adenoma in 4% with malignancy accounts for only 1-3% of the cases [1][2][3].…”