Four-dimensional CT (noncontrast agent enhanced, arterial, and delayed phases) provides superior preoperative localization in patients with primary hyperparathyroidism compared with sestamibi SPECT... Background There currently is no consensus on the optimal localization procedure and imaging protocol for parathyroid adenoma. Parathyroid four-dimensional (4D) CT has emerged as a promising method...

Hypoparathyroidism (HypoPT) is a rare disorder characterized by hypocalcemia in the presence of a low or inappropriately normal parathyroid hormone level. HypoPT is most commonly seen after neck surgery, which accounts for approximately 75% of cases, whereas approximately 25% have HypoPT due to nonsurgical causes. In both groups of patients, conventional therapy includes calcium and active vitamin D analogue therapy aiming to maintain serum calcium concentration in the low normal or just below the normal reference range and normalize serum phosphorus, magnesium concentrations, and urine calcium levels. The limitations of conventional therapy include wide fluctuations in serum calcium, high pill burden, poor quality of life, and renal complications. Parathyroid hormone (PTH) replacement therapy may improve the biochemical profile in those in whom conventional therapy proves unsatisfactory. Based on a systematic review and meta-analysis of the literature, the panel made a graded recommendation suggesting conventional therapy as first line therapy rather than administration of PTH (weak recommendation, low quality evidence). When conventional therapy is deemed unsatisfactory, the panel considers use of PTH. Because pregnancy and lactation are associated with changes in calcium homeostasis, close monitoring is required during these periods with appropriate adjustment of calcium and active vitamin D analogue therapy to ensure that serum calcium remains in the mid to low normal reference range in order to avoid maternal and fetal complications. Emerging therapies include molecules with prolonged PTH action as well as different mechanisms of action that may significantly enhance drug efficacy and safety. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

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.

Denosumab, which has been approved for the treatment of osteoporosis since 2010, is a fully humanised monoclonal antibody against a cytokine, receptor activator of nuclear factor kappa B ligand (RANKL), involved in bone resorption. Continued use of denosumab results in a potent and sustained decrease in bone turnover, an increase in bone mineral density (BMD), and a reduction in vertebral and hip fractures. The anti-resorptive effects of denosumab are reversible upon cessation, and this reversal is accompanied by a transient marked increase in bone turnover that is associated with bone loss, and of concern, an increased risk of multiple vertebral fractures. In this review, we outline the effects of denosumab withdrawal on bone turnover markers, BMD, histomorphometry, and fracture risk. We provide an update on recent clinical trials that sought to answer how clinicians can transition away from denosumab safely with follow-on therapy to mitigate bone loss and summarise the recommendations of various international guidelines.

The accuracy of FRAX® as a screening tool to identify osteoporosis and how it compares with tools such as Osteoporosis Self-Assessment Tool for Asians (OSTA), in Southeast Asian women has so far been unexplored. We aimed to determine the FRAX® thresholds that accurately identify densitometric osteoporosis and to compare its performance with that of OSTA for this purpose. Singaporean postmenopausal women (n = 1056) were evaluated. FRAX® Major Osteoporotic Fracture Probability (MOFP), Hip Fracture Probability (HFP) scores, and OSTA indices were calculated. Receiver operating characteristic (ROC) curves were constructed and via the Youden index, the optimal cut-off points of balanced sensitivity and specificity for dual energy X-ray absorptiometry (DXA)-defined osteoporosis were identified and the performance characteristics were compared. A FRAX® MOFP threshold of ≥3.7% had sensitivity, specificity, positive predictive value and negative predictive value of 0.78 (0.73–0.83), 0.63 (0.59–0.66), 0.4 (0.36–0.44), and 0.9 (0.87–0.92), respectively in identifying osteoporosis. The corresponding values for a HFP threshold of ≥0.6% were 0.85 (0.80–0.89), 0.58 (0.55–0.62), 0.39 (0.35–0.43), and 0.92 (0.9–0.94) and that for an OSTA index cut-off of ≤ −1.2 were 0.76 (0.70–0.81), 0.74 (0.71–0.77), 0.48 (0.43–0.54), and 0.91 (0.88–0.93). The area under the ROC curves were 82.8% (79.9%–85.6%), 77.6% (74.2%–81%), and 79.6% (76.5%–82.8%) for OSTA, MOFP, and HFP thresholds respectively. FRAX® and OSTA perform comparably in identifying osteoporosis in our population. OSTA has only 2 parameters and may be simpler to use. However, FRAX® may also have a role in primary screening to identify the postmenopausal woman to be referred for DXA scanning and may help facilitate fracture risk reduction discussions with the patient.