Comparison of [18F]fluorocholine PET/CT with [99mTc]sestamibi and ultrasonography to detect parathyroid lesions in primary hyperparathyroidism: a prospective study

Abstract

Background: Primary hyperparathyroidism is a common endocrine disorder produced by the increase of parathyroid hormone (PTH) due to a benign adenoma of a single parathyroid gland, or as multiple gland hyperplasia, or as a rare malignant tumor. Preoperative imaging scans are frequently necessary for the minimally invasive parathyroidectomies to identify the location of enlarged parathyroid glands and to design the procedure.

Methods: The diagnostic reliability of [¹⁸F]fluorocholine positron emission tomography/computed tomography (FCH PET/CT), [^99mTc]sestamibi [multiplexed ion beam imaging (MIBI)] and cervical ultrasonography was analyzed in 37 patients diagnosed with primary hyperparathyroidism undergoing minimally invasive parathyroidectomy. The three preoperative imaging techniques were correlated with intraoperative and histopathological findings as well as changes in biochemical parameters (serum PTH and calcium levels). Statistical analysis was carried out with SPSS version 24.0.

Results: In 30 of 37 patients (81.1%), FCH PET/CT correctly localized the pathological gland. In 3 cases of ectopic adenomas, the accuracy of the techniques was 100% (3/3) for FCH PET/CT, 66.7% (2/3) for MIBI, and 33.3% (1/3) for neck ultrasonography. Neither neck ultrasonography nor MIBI were able to locate pathological parathyroid glands in those patients with multiglandular disease, while FCH PET/CT correctly located one patient (1/3, 33.3%) with two adenomas and 3 patients (3/6, 50.0%) with hyperplasia. The three imaging techniques, FCH PET/CT, MIBI and neck ultrasound yielded a sensitivity of 92.1%, 57.9% and 32.4%, a positive predictive value of 94.6%, 84.6% and 78.6%, and a diagnostic accuracy of 96.4%, 85.7% and 79.0%, respectively.

Conclusions: In this group of patients diagnosed with primary hyperparathyroidism, FCH PET/CT was superior to MIBI and neck ultrasound in detecting adenomas, particularly in the presence of ectopic glands or multiglandular disease.

Keywords: Parathyroid adenoma; [18F]fluorocholine positron emission tomography/computed tomography ([18F]FCH PET/CT); [99mTc]sestamibi; neck ultrasonography; primary hyperparathyroidism (pHPT).

Figure 1

This was a 62-year-old woman with biochemical evidence of pPHT. [^99mTc]sestamibi (MIBI) scintigraphy images (A,B) were negative for abnormality. Neck ultrasonography images (not shown) were also negative. Axial [¹⁸F]fluorocholine PET/CT views (C,D) and maximum intensity projection (E) images, show focal right retrotracheal uptake corresponding to parathyroid adenoma (white and black arrow). The patient underwent minimally invasive surgery (2-cm diameter incision) achieving rapid detection and extraction of the lower right parathyroid gland (F). The presence of a parathyroid adenoma was histologically confirmed. pPHT, primary hyperparathyroidism; MIBI, multiplexed ion beam imaging; PET/CT, positron emission tomography/computed tomography.