Comparison of Planar Scintiscanning and Pinhole Subtraction Spect in Preoperative Imaging of Primary Hyperparathyroidism in an Endemic Goiter Area

A unilateral surgical approach in patients with primary hyperparathyroidism (HPTH) requires a reliable preoperative parathyroid localization procedure. The aim of this study was to compare the approved planar scintiscanning by means of (99m)TcO(4-)(201)Tl subtraction or (99m)Tc-sestamibi with (99m)TcO(4-) (201)Tl pinhole subtraction SPECT. Fifty patients with primary HPTH and preoperative localization diagnosis were retrospectively analyzed. Thirty-three of them underwent preoperative planar scintiscanning with (99m)TcO(4-) (201)Tl subtraction or (99m)Tc-sestamibi, 17 had (99m)TcO(4-) (201)Tl pinhole subtraction SPECT. Planar scintiscanning had an overall accuracy of 81.8%, (99m)TcO(4-) (201)Tl pinhole subtraction SPECT of 81.3%. In patients with solitary parathyroid adenomas the planar scintiscanning provided correct results in 86.7%, whereas (99m)TcO(4-)(201)Tl pinhole subtraction SPECT had an accuracy of 93.3% in these patients. Concomitant thyroid nodules diminished the accuracy of planar scanning to 78.6%. The accuracy of (99m)TcO(4-)(201)Tl pinhole subtraction SPECT was not diminished by multinodular goiter, all patients with solitary parathyroid adenomas and multinodular thyroid disease were accurately localized. The sensitivity of (99m)TcO(4-)(201)Tl pinhole subtraction SPECT is statistically not significantly different compared with planar (99m)TcO(4-) (201)Tl subtraction or (99m)Tc-sestamibi scintiscanning in patients with HPTH and solitary adenomas. Therefore, it is concluded that both imaging procedures are comparable in their diagnostic value for preoperative localization for successful unilateral parathyroidectomy. Although the results are not significantly different because of the number of patients, it is concluded (99m)TcO(4-) (201)Tl pinhole subtraction SPECT to be superior to planar scintiscanning in patients with underlying multinodular thyroid pathology.