Preoperative Localization for Primary Hyperparathyroidism: A Clinical Review

Abstract

With increasing use of minimally invasive parathyroidectomy (PTx) over traditional bilateral neck exploration in patients with primary hyperparathyroidism (PHPT), accurate preoperative localization has become more important to enable a successful surgical outcome. Traditional imaging techniques such as ultrasound (US) and sestamibi scintigraphy (MIBI) and newer techniques such as parathyroid four-dimension computed tomography (4D-CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) are available for the clinician to detect the diseased gland(s) in the preoperative workup. Invasive parathyroid venous sampling may be useful in certain circumstances such as persistent or recurrent PHPT. We review the diagnostic performance of these imaging modalities in preoperative localization and discuss the advantages and weaknesses of these techniques. US and MIBI are established techniques commonly utilized as first-line modalities. 4D-CT has excellent diagnostic performance and is increasingly performed in first-line setting and as an adjunct to US and MIBI. PET and MRI are emerging adjunct modalities when localization has been equivocal or failed. Since no evidence-based guidelines are yet available for the optimal imaging strategy, clinicians should be familiar with the range and advancement of these techniques. Choice of imaging modality should be individualized to the patient with consideration for efficacy, expertise, and availability of such techniques in clinical practice.

European expert consensus on practical management of specific aspects of parathyroid disorders in adults and in pregnancy: recommendations of the ESE Educational Program of Parathyroid Disorders (PARAT 2021)

“…Preoperative localization of abnormal parathyroid glands is crucial for the success of minimally invasive PTX, and concordance of two imaging methods may result in very high positive predictive values for correct localization of adenoma(s) (176). Avoiding radiation exposure in pregnancy is critical for guiding decisions on the choice of imaging methods for PHPT.…”

“…The fetal exposure by a 99mTc-MIBI scan is lower than the exposure associated with fetal harm (177). 18F-Fluorocholine PET/CT is even considered to have a lower overall (maternal) radiation dose than 99mTc-MIBI SPECT/CT, but the fetal radiation exposure by 18F-Fluorocholine PET/CT is not exactly known and might even be higher due to increased fetal tracer uptake (176). 4D-CT has the highest radiation dose and should be avoided during pregnancy (176).…”

“…18F-Fluorocholine PET/CT is even considered to have a lower overall (maternal) radiation dose than 99mTc-MIBI SPECT/CT, but the fetal radiation exposure by 18F-Fluorocholine PET/CT is not exactly known and might even be higher due to increased fetal tracer uptake (176). 4D-CT has the highest radiation dose and should be avoided during pregnancy (176). To provide rough guidance for pregnant women with PHPT and an indication for surgery, we consider it reasonable to aim for two different preoperative imaging methods, preferably ultrasonography in combination with either 99mTc-MIBI scan or 4D-dynamic contrast-enhanced MRI.…”

Management and Long-Term Follow-Up of Hyperparathyroidism in Multiple Endocrine Neoplasia Type 1: Single Center Experience

“…Several studies have proposed preoperative localization procedures that are more sensitive to detect multiglandular disease, small lesions, or possible ectopic parathyroid tissue in MEN1-related PHPT, such as 18F-fluorocholine PET/CT (FCH-PET/CT), with or without enhanced arterial imaging, and four-dimensional computed tomography (4D-CT), especially when conventional preoperative imaging before the first intervention is inconclusive [ 19 , 20 , 21 , 22 ]. In particular, the performance of 18F-FCH-PET/CT in PHPT appears to be superior compared to commonly used imaging using 99m Tc-sestamibi scintigraphy, ultrasound, and 4D-CT [ 21 , 23 , 24 , 25 , 26 ], and provides valuable information even in cases with recurrent disease and negative or equivocal 99m Tc-sestamibi scintigraphy and/or ultrasound.…”

Percentage arterial enhancement on 2D CT in the diagnosis of primary hyperparathyroidism: A prospective validation study and potential pitfalls

“…Written informed consent was obtained from each patient prior to inclusion. Inclusion criteria for enrolment in the study were patients (1) with biochemically proven PHPT. The biochemical criteria for the diagnosis of PHPT were a high serum calcium (higher than the upper limit of normal for assay, i.e., more than 10.5 mg/dL) with unsuppressed PTH (more than 30 pg/mL); (2) eligible and willing for surgery (surgery naïve as well as reoperative cases); (3) willing to participate in the study and undertake a 2DCT scan for localization.…”