99mTc-Sestamibi/123I Subtraction SPECT/CT in Parathyroid Scintigraphy: Is Additional Pinhole Imaging Useful?

Abstract

<h3>Abstract</h3><div><h4>Objectives: </h4><p>This retrospective study evaluated whether the use of additional anterior ^99mTc-sestamibi/¹²³I pinhole imaging improves the outcome of ^99mTc-sestamibi/¹²³I subtraction SPECT/CT in parathyroid scintigraphy (PS).</p><h4>Materials and Methods: </h4><p>PS using simultaneous dual-isotope subtraction methods and an acquisition protocol combining SPECT/CT and planar pinhole imaging was performed for 175 patients with primary or secondary hyperparathyroidism. All patients who proceeded to surgery with complete postsurgery laboratory findings were included in this study (<i>n</i> = 94). SPECT/CT images alone and combined with pinhole images were evaluated.</p><h4>Results: </h4><p>There were 111 enlarged parathyroid glands of which 104 and 108 glands were correctly visualized by SPECT/CT (seven false positives) or SPECT/CT with pinhole (three false positives), respectively. Both sensitivity and specificity were higher with combined SPECT/CT with pinhole than with SPECT/CT alone (97% versus 94% and 99% versus 98%, resp., not significant). The false-positive rate was 6% with SPECT/CT and decreased to 3% using combined SPECT/CT with pinhole.</p><h4>Conclusion: </h4><p>^99mTc-sestamibi/¹²³I subtraction SPECT/CT is a highly sensitive and specific protocol for PS. The use of additional anterior pinhole imaging increases both sensitivity and specificity of PS, although this increase is not statistically significant.<br /></p></div>