Diagnostic Performance of 4D CT and Sestamibi SPECT/CT in Localizing Parathyroid Adenomas in Primary Hyperparathyroidism

Abstract

ver the past 2 decades, minimally invasive parathy roidectomy has been widely adopted because of improved preoperative imaging and routine use of in traoperative parathyroid hormone monitoring (1). The rationale for this surgical approach is that most patients with primary hyperparathyroidism have a single, benign parathyroid adenoma (up to 88%) (2). Compared with bilateral neck exploration, minimally invasive parathy roidectomy is associated with lower complication rates, shorter operation times, reduced costs, and improved cosmetic results while it maintains similar cure rates (3). Accurate preoperative localization of a single para thyroid adenoma is critically important to the success of minimally invasive parathyroidectomy because it directs the surgeon to the adenoma, without which minimally invasive parathyroidectomy becomes a problematic surgi cal approach (4,5). Conversely, negative or equivocal pre operative imaging directs the surgeon to the less focused bilateral neck exploration. With a variety of imagingbased localization mo dalities available and different acquisition protocols within a given modality, to our knowledge there is no current consensus regarding the optimal localization procedure and imaging protocol (6). The choice often depends on regional imaging capabilities, radiologist expertise, and surgeon preference. Many institutions

European multicentre study on outcome of surgery for sporadic primary hyperparathyroidism

“…In the present study, a head-to-head comparison of other localization procedures with ultrasonography or sestamibi scintigraphy was not performed owing to small numbers. It has been suggested that four-dimensional CT is superior to sestamibi scintigraphy 18 , and choline PET with or without low-dose CT has recently been proposed to have excellent sensitivity and specificity 19 . Choline PET has lower radiation exposure 20 , but comes at increased cost and the investigation is less widely available.…”

Parathyroid Scintigraphy: How Does It Fit In?

“…If the distribution of gland size in the series is skewed toward smaller glands, it will introduce a bias against scintigraphy. The sizes of the resected parathyroid glands were not reported by Yeh et al (1).…”

“…It is therefore helpful to know the prevalence of thyroid disorders in any series that evaluates scintigraphy of the parathyroid. Concomitant thyroid pathologic analysis is not described by Yeh et al (1).…”

“…The study by Yeh et al (1) in this issue of Radiology compared 4D CT with technetium 99m ( 99m Tc) sestamibi SPECT/CT for localization of the culprit parathyroid glands in primary hyperparathyroidism. The authors performed a single-center retrospective analysis of 400 patients, all of whom underwent 4D CT and dual-phase 99m Tc-sestamibi SPECT/CT at a single examination; all underwent parathyroidectomy within 6 months of imaging.…”

“…To conclude, it might be premature to abandon well-established parathyroid scintigraphy. The study by Yeh et al (1) was not designed to investigate the role of scintigraphy in patients who already underwent neck surgery, who were unable to receive iodinated contrast media, or who had secondary hyperparathyroidism. The postoperative neck can be particularly difficult to assess because of altered anatomic landmarks.…”