Ectopic parathyroid adenoma proved by diagnostic CT.

Primary hyperparathyroidism (PHPT) is the most prevalent cause of hypercalcaemia, affecting 0.3% of the population. The only curative procedure is parathyroidectomy. Ectopic adenomas are challenging to localize and frequently result in persistent PHPT. This is a case report of a 29-year-old male patient who was diagnosed with PHPT prior to neck surgery and reoperated with bilateral neck exploration. However, the PHPT was not cured, until diagnostic CT with contrast had helped localizing a 1 cm ectopic parathyroid adenoma in the right horn of the thymus gland. The adenoma was then removed successfully.

Is intraoperative parathyroid monitoring during minimally invasive parathyroidectomy still justified?

Introduction: Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. With parathyroidectomy, a cure rate of over 95% at initial surgery is reported. Localization of the abnormal parathyroid gland is critical for the operation to be successful. The aim of this study is to analyze data of patients with single gland disease (SGD) and positive concordant localization imaging undergoing minimally invasive parathyroidectomy (MIP) and intraoperative parathyroid hormone monitoring (IOPTH) to evaluate if IOPTH is still justified in patients with localized SGD. Methods: A retrospective database analysis of all minimally invasive operations with IOPTH for PHPT and positive concordant localization in ultrasound (US) and 99mTc-sestamibi scintigraphy (MIBI) between 2016-2021. When both US and MIBI were negative, patients underwent either choline or methionine PET-CT. The patients were also analyzed a second time without applying IOPTH. Results: In total, 198 patients were included in the study. The sensitivity of US, MIBI and PET-CT was 96%, 94% and 100%, respectively. Positive predictive value was 88%, 89% and 94% with US, MIBI and PET-CT, respectively. IOPTH was true positive in 185 (93.4%) patients. In 13 (6.6%) patients, no adequate IOPTH decline was observed after localizing and extirpating the assumed enlarged parathyroid gland. Without IOPTH, the cure rate decreased from 195 (98.5%) to 182 (92%) patients and the rate of persisting disease increased from 2 (1.0%) to 15 (7.5%) patients. Conclusion: Discontinuing IOPTH significantly increases the persistence rate by a factor of 7.5 in patients with concordantly localized adenoma. Therefore, IOPTH appears to remain necessary even for this group of patients.

RadioGraphics Update: Parathyroid CT and Primary Hyperparathyroidism.

Editor's Note.-RadioGraphics Update articles supplement or update information found in full-length articles previously published in RadioGraphics. These updates, written by at least one author of the previous article, provide a brief synopsis that emphasizes important new information such as technological advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes.

Comparison of intraoperative imaging with a portable gamma camera with extemporaneous histology in minimally invasive surgery for primary hyperparathyroidism.

INTRODUCTION: The curative treatment of primary hyperparathyroidism (PPH) is surgical and today it can be performed by minimally invasive surgery (MIS) and also be radioguided (RG) if a radiopharmaceutical with affinity for the parathyroid tissue that can be detected with gamma-detector probes or with a portable gamma camera (PGC) is injected. AIM: The objective is to assess whether intraoperative scintigraphy (GGio) with PGC can replace intraoperative pathological anatomy (APio) to determine if the removed specimen is an abnormal parathyroid. MATERIAL AND METHOD: 92 patients underwent CMI RG--HPP with PGC after the administration of a dose of 99 mTc-MIBI. The information provided by the PGC in the analysis of the excised specimens is qualitatively compared (capture yes/no) with the result of the intraoperative pathological anatomy (APio). The Gold standard is the definitive histology. RESULTS: 120 excised pieces are evaluated with GGio and APio. There were 110 agreements (95TP and 15TN) and 10 disagreements (3FP and 7FN). Of the 120 lesions, 102 were parathyroid and 18 were non-parathyroid. There was good agreement between intraoperative scintigraphy imaging (GGio) and PA, 70.1% according to Cohen's Kappa index. The GGio presented the following values ​​of Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, Positive Likelihood Ratio, Negative Likelihood Ratio and Overall Value of the Test (93.1%, 83.3%, 96.9%, 68.2%, 5.59, 0.08 and 0.92 respectively). CONCLUSION: GGio is a rapid and effective surgical aid technique to confirm/rule out the possible parathyroid nature of the lesions removed in PPH surgery, but it cannot replace histological study.

Primary hyperparathyroidism caused by a tiny mediastinal parathyroid adenoma with non-localising imaging studies.

Variations in parathyroid gland positions often cause failure in initial parathyroid adenoma surgery, especially when imaging fails to localise the adenoma. This report describes a female patient with primary hyperparathyroidism for which preoperative localisation studies did not determine the position of the hyperfunctioning gland. The initial approach with bilateral cervical exploration and intraoperative parathyroid hormone monitoring was performed unsuccessfully. A mediastinal adenoma was suspected due to meticulous negative neck exploration and repeated negative images for a neck adenoma. Subsequently, a second approach involving mediastinal exploration was performed. After the removal of remnant thymic tissue in the mediastinal space, a significant drop in intraoperative parathyroid hormone levels was achieved. The pathological result confirmed the presence of a tiny pathological parathyroid adenoma within the thymus. At 6 months follow-up, postoperative biochemical assessment was consistent with normal calcium and parathyroid hormone levels.

Parathyroid Adenoma Orientation for Gland Embryologic Origin on Ultrasonography.

Importance: Accurate preoperative localization is critical to success in targeted parathyroidectomy for primary hyperparathyroidism. Objective: To determine if the association between the long axis of a parathyroid adenoma (PTA) candidate and strap musculature on sagittal ultrasonography (US) can be used to predict the embryologic origin of the gland. Design, Setting, and Participants: This diagnostic study was performed using the Stanford Research Repository. Patients 18 years or older with primary hyperparathyroidism who underwent parathyroidectomy between January 2009 and October 2021 were considered. Additional inclusion criteria were having clear sagittal view of the adenoma candidate on US, confirmation of the gland of origin intraoperatively, and confirmation of hypercellular parathyroid on final pathology. Data were analyzed from October 2021 to June 2022. Exposures: B-mode US and surgical parathyroidectomy. Main Outcomes and Measures: The index test was using US to measure the angle between the long axis of an adenoma candidate and the strap musculature in the sagittal plane. This angle was used to test whether inferior and superior PTAs could be accurately assigned. The hypothesis was formulated prior to data collection. Results: A total of 426 patients (mean [range] age, 61.1 [20-96] years; 316 [74.2%] female) with 442 adenomas met inclusion criteria. Of the 442 adenomas, 314 (71.0%) had measurable angles, of which 204 (46.2%) were assigned a superior origin, 238 (53.8%) were assigned an inferior origin, and 128 (29%) were indeterminate. Of the surgically identified superior PTAs, 144 (70.6%) had a definable angle, and of the surgically identified inferior PTAs, 170 (71.4%) had a definable angle. The receiver operating characteristic analysis found 94° as the optimized angle for differentiating true negatives from true positives, with an overall sensitivity of 74% and specificity of 72%. This supported using 90° as a break point for US review. True positives were considered superior adenomas with an angle greater than 90°; true negatives were inferior adenomas with an angle less than 90°. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of angulation analysis for determining PTA origin were 72.2% (95% CI, 64.9%-79.5%), 73.5% (95% CI, 66.9%-80.1%), 69.8% (95% CI, 62.5%-77.1%), 75.8% (95% CI, 69.3%-82.3%), and 72.9%, respectively. A subgroup analysis of 426 adenomas using the posterior carotid artery border on transverse US as a surrogate for predicting gland origin showed the following for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy: 49.5% (95% CI, 42.6%-56.4%), 82.3% (95% CI, 77.3%-87.3%), 71.4% (95% CI, 63.9%-78.9%), 64.6% (95% CI, 59.1%-70.1%), and 66.9%, respectively. Conclusions and Relevance: This diagnostic study showed that PTA angulation on sagittal plane US can be used to predict gland of origin and guide surgery. The relationship between adenoma and posterior carotid artery border on transverse US can also be used to predict gland origin. These easy-to-apply US-based tests can be used in conjunction with other imaging modalities to guide targeted parathyroidectomy.

F18-Choline PET/CT or MIBI SPECT/CT in the Surgical Management of Primary Hyperparathyroidism: A Diagnostic Randomized Clinical Trial.

Importance: Whether F18-choline (FCH) positron emission tomographic (PET)/computed tomographic (CT) scan can replace Tc99m-sestaMIBI (MIBI) single-photon emission (SPE)CT/CT as a first-line imaging technique for preoperative localization of parathyroid adenomas (PTA) in patients with primary hyperparathyroidism (PHPT) is unclear. Objective: To compare first-line FCH PET/CT vs MIBI SPECT/CT for optimal care in patients with PHPT needing parathyroidectomy and to compare the proportions of patients in whom the first-line imaging method resulted in successful minimally invasive parathyroidectomy (MIP) and normalization of calcemia 1 month after surgery. Design, Setting, and Participants: A French multicenter randomized open diagnostic intervention phase 3 trial was conducted. Patients were enrolled from November 2019 to May 2022 and participated up to 6 months after surgery. The study included adults with PHPT and an indication for surgical treatment. Patients with previous parathyroid surgery or multiple endocrine neoplasia type 1 (MEN1) were ineligible. Interventions: Patients were assigned in a 1:1 ratio to receive first-line FCH PET/CT (FCH1) or MIBI SPECT/CT (MIBI1). In the event of negative or inconclusive first-line imaging, they received second-line FCH PET/CT (FCH2) after MIBI1 or MIBI SPECT/CT (MIBI2) after FCH1. All patients underwent surgery under general anesthesia within 12 weeks following the last imaging. Clinical and biologic (serum calcemia and parathyroid hormone levels) assessments were performed 1 and 6 months after surgery. Main Outcomes and Measures: The primary outcome was a true-positive first-line imaging-guided MIP combined with uncorrected serum calcium levels of 2.55 mmol/l or less 1 month after surgery, corresponding to the local upper limit of normality. Results: Overall, 57 patients received FCH1 (n = 29) or MIBI1 (n = 28). The mean (SD) age of patients was 62.8 (12.5) years with 15 male (26%) and 42 female (74%) patients. Baseline patient characteristics were similar between groups. Normocalcemia at 1 month after positive first-line imaging-guided MIP was observed in 23 of 27 patients (85%) in the FCH1 group and 14 of 25 patients (56%) in the MIBI1 group. Sensitivity was 82% (95% CI, 62%-93%) and 63% (95% CI, 42%-80%) for FCH1 and MIBI1, respectively. Follow-up at 6 months with biochemical measures was available in 43 patients, confirming that all patients with normocalcemia at 1 month after surgery still had it at 6 months. No adverse events related to imaging and 4 adverse events related to surgery were reported. Conclusions: This randomized clinical trial found that first-line FCH PET/CT is a suitable and safe replacement for MIBI SPECT/CT. FCH PET/CT leads more patients with PHPT to correct imaging-guided MIP and normocalcemia than MIBI SPECT/CT thanks to its superior sensitivity. Trial Registration: ClinicalTrials.gov Identifier: NCT04040946.

Update in imaging tests used for the localization of parathyroid pathology.

Preoperative localization of parathyroid pathology, generally a parathyroid adenoma, can be difficult in some cases due to the anatomical variants that these glands present. The objective of this review is to analyse the different imaging techniques used for preoperative localization of parathyroid pathology (scintigraphy, ultrasound, CT, MRI and PET). There is great variability between the different tests for the preoperative localization of parathyroid pathology. The importance of knowing the different diagnostic options lies in the need to choose the most suitable test at each moment and for each patient for an adequate management of primary hyperparathyroidism (PHP) with surgical criteria.

4D SPECT/CT: A Hybrid Approach to Primary Hyperparathyroidism.

Our rationale was to review the imaging options for patients with primary hyperparathyroidism and to advocate for judicious use of 4-dimensional (4D) SPECT/CT to visualize diseased parathyroid glands in patients with complex medical profiles or in whom other imaging modalities fail. We review the advantages and disadvantages of traditional imaging modalities used in preoperative assessment of patients with primary hyperparathyroidism: ultrasound, SPECT, and 4D CT. We describe a scheme for optimizing and individualizing preoperative imaging of patients with hyperfunctioning parathyroid glands using traditional modalities in tandem with 4D SPECT/CT. Using the input from radiologists, endocrinologists, and surgeons, we apply patient criteria such as large body habitus, concomitant multiglandular disease, multinodular thyroid disease, confusing previous imaging, and unsuccessful previous surgery to create an imaging paradigm that uses 4D SPECT/CT yet is cost-effective, accurate, and limits extraneous radiation exposure. 4D SPECT/CT capitalizes on the strengths of SPECT and 4D CT and addresses limitations that exist when these modalities are used in isolation. In select patients with complicated clinical parameters, preoperative imaging with 4D SPECT/CT can improve accuracy yet remain cost-effective.

Ultrasonographic Detective Flow Imaging for Evaluating Parathyroid Adenoma in Patients with Primary Hyperparathyroidism.

BACKGROUND: Detective flow imaging (DFI) is a new imaging technology that displays low-velocity blood flow, which is difficult to visualize on conventional color Doppler ultrasonography (CDU). In this study, we compared the usefulness of DFI with that of CDU and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for detecting parathyroid adenoma (PA) in patients with primary hyperparathyroidism (PHPT). METHODS: From March 2021 to March 2023, 87 PHPT patients underwent surgery, and 66 had a single PA. We performed preoperative conventional ultrasonography with CDU, MIBI scintigraphy, and DFI for 42 patients (5 males and 37 females; mean age: 61.6 ± 15.4 years). RESULTS: MIBI scintigraphy detected PA in 85.7% (36/42) patients, and both CDU and DFI detected PA in all patients. The rates of vascularity in PA detected by CDU and DFI were 71.4% (30/42) and 85.7% (36/42), respectively. Vascularity was detected by DFI in 6 patients who were negative for vascularity on MIBI scintigraphy. Furthermore, DFI detected blood supply in 6 of the 12 patients with undetectable blood supply on CDU. Fisher's exact test revealed that high or low blood flow, as determined by DFI, was significantly associated with detection of feeding vessels in PA by CDU (P < 0.001). CONCLUSIONS: DFI was useful for preoperative detection of PA blood flow.

Clinical predictors of negative/equivocal SPECT imaging outcomes in primary hyperparathyroidism: Factors calling for 18F-choline-PET.

PURPOSE: For minimally invasive surgery of parathyroid adenomas, exact localization diagnostics are essential. Main imaging modalities used for diagnostics are sonography, SPECT with/without CT (traditional imaging) and 18F-choline-PET. The aim of our study was to identify predictors for inconclusive SPECT imaging and subsequently determine in which cases 18F-choline-PET is needed. METHODS: Retrospective analysis of 138 patients with histologically confirmed primary hyperparathyroidism (pHPT). After sonography, patients underwent SPECT or SPECT/CT imaging, with subsequent 18F-choline-PET in cases of disconcordant results. Logistic regression analysis was used to identify clinical and laboratory factors predictive for negative SPECT results. RESULTS: Sensitivity rates for sonography, SPECT, SPECT/CT, and choline-PET were 47 %, 49 %, 71.7 %, and 97 %, respectively. Logistic regression revealed lower PTH levels (p < 0.001), presence of structural thyroid disease (p = 0.018), and negative sonography (p < 0.001) as predictive of negative/equivocal SPECT outcome. An additional traditional imaging CT scan to a SPECT enhanced detection odds, as did greater adenoma weight. Urolithiasis, osteoporosis, and calcium values as measurement of activity and duration of disease showed no significant association with the detection rate. Furthermore, our study demonstrated that 18F-choline-PET exhibited remarkable sensitivity in detecting adenomas among patients with negative/equivocal SPECT results. CONCLUSION: Our study reveals potential predictive factors for a negative/equivocal SPECT outcome in pHPT. Identifying these factors might allow minimizing futile SPECT examinations and perhaps encourage timely utilization of 18F-choline-PET imaging. Our study reinforces the clinical significance of 18F-choline-PET, especially in complex cases with disconcordant results by conventional parathyroid imaging methods.

Use of [18F]fluorocholine PET/CT in the detection of primary hyperparathyroidism in paediatrics: a case report.

OBJECTIVES: The most common cause of primary hyperparathyroidism (PPH) in children is a parathyroid adenoma. Among this population, PPH exhibits higher levels of morbidity, severity and target organ involvement compared to adults. When there is suspicion of PPH, cervical ultrasound and 99mTc-sestamibi SPECT/CT are the imaging test traditionally indicated. Among adults, the use of [18F]fluorocholine PET/CT has shown a higher sensitivity than ultrasound and [99mTc]sestamibi SPECT/CT, leading to an expanding adoption in recent years. However, its role in paediatrics has not been clearly defined yet. CASE PRESENTATION: The patient is an adolescent female aged 13 years presented with lithiasis. The analytical study revealed elevated PTH, hipovitaminosis D, hypercalcaemia and hypophosphataemia. Due to the suspicion of PPH, cervical ultrasound and 99mTc-sestamibi SPECT/C were performed, failing to identify hyperfunctioning parathyroid glands. We proceeded to carry out a [18F]fluorocholine PET/CT where a hypermetabolic nodular image was identified, compatible with a hyperfunctioning parathyroid adenoma. The patient underwent surgery, resulting in the normalisation of PTH levels. Pathological anatomy confirmed the presence of a parathyroid adenoma. CONCLUSIONS: In cases where conventional imaging tests yield negative results or discrepancies, we suggest the possibility of the use of [18F]fluorocholine PET/CT for the detection of hyperfunctioning parathyroid adenomas.

Don't chase the adenoma: A probabilistic approach to imaging before parathyroidectomy.

BACKGROUND: Preoperative imaging before parathyroidectomy can localize adenomas and reduce unnecessary bilateral neck explorations. We hypothesized that (1) the utility of preoperative imaging varies substantially depending on the preoperative probability of having adenoma(s) and (2) that a selective imaging approach based on this probability could avoid unnecessary patient costs and radiation. METHODS: We analyzed 3,577 patients who underwent parathyroidectomy for primary hyperparathyroidism from 2001 to 2022. The predicted probability of patients having single or double adenoma versus hyperplasia was estimated using logistic regression. We then estimated the relationship between the predicted probability of single/double adenoma and the likelihood that sestamibi or 4-dimensional computed tomography was helpful for operative planning. Current Medicare costs and published data on radiation dosing were used to calculate costs and radiation exposure from non-helpful imaging. RESULTS: The mean age was 62 ± 13 years; 78% were women. Adenomas were associated with higher mean calcium (11.2 ± 0.74 mg/dL) and parathyroid hormone levels (140.6 ± 94 pg/mL) than hyperplasia (9.8 ± 0.52 mg/dL and 81.4 ± 66 pg/mL). The probability that imaging helped with operative planning increased from 12% to 65%, as the predicted probability of adenoma increased from 30% to 90%. For every 10,000 patients, a selective approach to imaging that considered the preoperative probability of having adenomas could save patients up to $3.4 million and >239,000 millisieverts of radiation. CONCLUSION: Rather than imaging all patients with primary hyperparathyroidism, a selective strategy that considers the probability of having adenomas could reduce costs and avoid excess radiation exposure.

Microwave ablation for recurrent primary hyperparathyroidism in four patients with multiple endocrine neoplasia type 1: a case series report.

Multiple endocrine neoplasia type 1 (MEN1), a rare tumor syndrome, is inherited in an autosomal dominant pattern, mainly manifested as primary hyperparathyroidism (PHPT). Surgery is preferred for patients with MEN1 and PHPT. Thermal ablation has been widely applied for PHPT but rarely for postoperative recurrent PHPT in MEN1 patients. Based on a series of cases, we aimed to investigate the clinical efficacy and safety of ultrasound-guided percutaneous microwave ablation in the treatment of MEN1 patients with postoperative recurrence of PHPT.

Diagnostic Performance of 99mTc-Sestamibi SPECT/CT and 18F-Choline PET/CT in Locating Hyperfunctioning Parathyroid Glands in Patients with Primary Hyperparathyroidism.

OBJECTIVE: This study aimed to assess the diagnostic performance of 99mTc-sestamibi SPECT/CT and 18F-choline PET/CT in detecting hyperfunctioning parathyroid glands in patients undergoing surgery for primary hyperparathyroidism (PHPT). METHODS: A retrospective analysis was conducted on patients who underwent PHPT-related surgery between April 2019 and May 2022. The study focused on patients undergoing either 99mTc-sestamibi SPECT/CT (81 patients) or 18F-choline PET/CT (33 patients) scans before surgery to pinpoint hyperfunctioning parathyroid gland(s). In the majority of patients, 18F-choline PET/CT was performed after negative or inconclusive findings on 99mTc-sestamibi SPECT/CT. Pathohistological reports were utilized as the reference standard for evaluating the accuracy of the imaging findings. RESULTS: The study encompassed 83 patients (70 females, 84.3%) with an average age of 57.2 years (24-80 years). The pathohistological analysis identified a total of 98 glands. In a per-lesion analysis, the detection rate of 99mTc-sestamibi SPECT/CT was 57% (95% CI 45.3-68.1), while the detection rate of 18F-choline PET/CT was 90.3% (95% CI 74.3-98.0). CONCLUSION: The results of our study showed the significant usefulness of 18F-choline PET/CT in patients with negative or inconclusive results of 99mTc-sestamibi SPECT/CT in accurately locating hyperfunctioning parathyroid glands in PHPT patients.

Assessment of left ventricular dysfunction by strain echo in primary hyperparathyroidism and its reversal after parathyroidectomy.

BACKGROUND: Strain echocardiography is a highly sensitive modality for detecting myocardial disease at an early stage. Therefore, we aim to evaluate subclinical left ventricular dysfunction in primary hyperparathyroidism (PHPT) patients with myocardial strain imaging in addition to conventional echocardiography and to look for its reversal after parathyroidectomy (PTx). METHODS: Thirty patients who underwent curative parathyroidectomy for PHPT were included. All patients were evaluated with M mode echo, 2D echo and strain imaging before and 6 months after PTx. Left ventricular ejection fraction, left ventricular diastolic dysfunction, left ventricular hypertrophy (LVH), Global Longitudinal Strain (GLS) and global circumferential strain (GCS) were recorded. RESULTS: On M mode echo, LVH was present in 15 patients and 8 of them improved completely after PTx (p < 0.038). Incidence of systolic and diastolic dysfunction on 2D echo was 10% and 13.3% respectively; while myocardial strain imaging showed impaired systolic function in 46.7% patients. Hence, compared to conventional 2D echo, strain imaging showed 36.7% high detection rate of subnormal cardiac function. There was improvement in left ventricle dysfunction (p = 0.083), GLS and GCS (p = 0.034) after PTx. Serum parathormone demonstrated a strong positive correlation with change in GLS and GCS (p = 0.013, p = 0.126) while serum calcium showed a weak correlation with change in GLS and GCS following surgery. CONCLUSION: Myocardial strain imaging should be considered for all PHPT patients as early identification of subclinical ventricle dysfunction provides an opportunity for an early intervention and thereby preventing development of irreversible LV dysfunction.

Surgery for nonlocalizing hyperparathyroidism in high volume center.

BACKGROUND: Patients with nonlocalizing hyperparathyroidism pose a significant challenge to surgeons when undergoing neck exploration for parathyroidectomy. METHODS: We evaluated 536 patients that had parathyroidectomy for primary hyperparathyroidism (PHPT) from 2005 to 2018 at a single tertiary academic center, and 155 (29%) had standard nonlocalizing preoperative imaging (negative ultrasound and sestamibi scans). RESULTS: There were a total of 102 (66%) non-ectopic single adenomas in the nonlocalizing group and 325 (85%) single adenomas in the localizing group. There was no significant difference (p = 0.09) in adenoma quadrant between localizing and nonlocalizing single adenomas, but the most common location in both groups was right inferior. Patients with nonlocalizing scans were more likely to have double adenomas (21% vs. 9%, p < 0.001), ectopic glands (10% vs. 5%, p = 0.052), and multi-gland disease (13% vs. 8%, p = 0.002). CONCLUSION: Nonlocalizing PHPT patients experienced similar cure and complication rates as localizing PHPT, but required more bilateral explorations and increased operative time.

Four-Dimensional Computed Tomography for Parathyroid Adenoma Localization: A Pre-Operative Imaging Protocol.

OBJECTIVE: Primary hyperparathyroidism (PHPT) affects approximately 0.86% of the population, with surgical resection as the treatment of choice. A 4D computed tomography (CT) is a highly effective tool in localizing parathyroid adenomas; however, there is currently no defined role for 4D CT when stratified against ultrasonography (USG) and nuclear medicine Technetium Sestamibi SPECT/CT (SES) imaging. STUDY DESIGN: Retrospective Study. SETTING: University Hospital. METHODS: All patients who underwent parathyroidectomy for PHPT between 2014 and 2019 at a single institution were reviewed. Patients who had a 4D CT were included. We compared outcomes of 4D CT as a second line imaging modality to those of USG and SES as first line modalities. An imaging algorithm was proposed based on these findings. RESULTS: There were 84 patients identified who had a 4D CT after unsuccessful first line imaging. A 4D CT localized parathyroid adenoma to the correct quadrant in 64% of cases, and to the correct laterality in 75% of cases. Obese patients had significantly lower rates of adenoma localization with USG (33.4%), compared to non-obese patients (67.5%; P = .006). In determining multigland disease the sensitivity of 4D CT was 86%, while the specificity was 87%. CONCLUSIONS: A 4D CT has impressive rates of accurate localization of parathyroid adenomas; however due to the radiation exposure involved, it should remain a second line imaging modality. PHPT patients should first be evaluated with USG, with 4D CT used if this is unsuccessful and patients are greater than 40 years old, have a high BMI, or are having revision surgery.

Ultrasound-based quantitative tools in predicting renal involvement in asymptomatic primary hyperparathyroidism.

PURPOSE: Asymptomatic primary hyperparathyroidism (aPHPT) has been recognized as a condition that can lead to renal complications. Timely identification of prognostic indicators for renal impairment holds the potential to facilitate proactive monitoring and treatment strategies in these patients. This study aims to investigate the utility of acoustic radiation force impulse (ARFI) imaging and renal resistive index (RRI), in identifying renal parenchymal and vascular changes in patients with aPHPT. METHODS: Forty-two patients with aPHPT and 42 controls matched for age, sex, and body mass index were included in the study. The presence of renovascular changes was evaluated by RRI measurement with Doppler ultrasonography, and the presence of renal parenchymal involvement was evaluated by ARFI quantification, given as shear wave velocity (SWV). RESULTS: In aPHPT patients, both the mean RRI and mean SWV values exhibited substantial elevation compared to the control group (P < 0.001 for both). Significant associations were observed between SWV values and serum calcium, parathyroid hormone (PTH), and adenoma size within the patient group (P < 0.001, P < 0.001, P = 0.016, respectively). Similarly, the mean RRI demonstrated positive correlations with serum calcium and PTH levels in the patient group (P< 0.001, P = 0.011, respectively). Multivariate linear regression analysis underscored the connection between mean RRI and mean SWV values with serum calcium levels within the patient group. In addition, serum PTH levels affected mean SWV positively and significantly. CONCLUSION: The use of ARFI imaging and RRI measurements appears to hold potential in identifying renal involvement in patients with aPHPT.

Site specific differences in vBMD and geometry in postmenopausal women with primary hyperparathyroidism.

PURPOSE: Primary Hyperparathyroidism (PHPT) is associated with catabolic effects at both trabecular and cortical bone. Mechanical loading is one of the most important natural anabolic stimuli for bone at all ages. The present study was designed to assess the impact of PHPT on vBMD and bone geometry using peripheral quantitative computed tomography (pQCT) at the radius and tibia, sites with similar structural characteristics, but subject to different loading conditions. METHODS: We evaluated the impact of PHPT on bone, by comparing the z-scores of volumetric Bone Mineral Density (vBMD) and indices of bone geometry simultaneously at the tibia and the radius by pQCT, skeletal sites with similar structure, but subject to different loading conditions. Forty-one postmenopausal women with PHPT and 79 controls, comprised the study group. RESULTS: At both trabecular and cortical sites, vBMD and bone geometry indices were significantly lower in patients compared with controls. In patients with PHPT, apart from a lower z-score for total vBMD (p = 0.01) at the radius, there was no other difference between the radius and the tibia at the trabecular sites. On the contrary, at cortical sites, the z-scores of cortical bone mineral content (p = 0.02), cortical vBMD (p = 0.01) and cortical cross-sectional area (p = 0.05) were significantly lower at the radius compared with the tibia, indicating that cortical bone at the weight bearing tibia might be less affected by the catabolic actions of continuous parathyroid hormone (PTH) exposure. PTH levels were positively associated with the difference in z-scores of cort BMD (r = 0.439, p < 0.01) indicating that in more severe cases, as expressed by higher PTH levels, the deleterious effects at the non-weight bearing radius might be accentuated. CONCLUSION: We found that in postmenopausal women with PHPT, both trabecular and cortical bone are adversely affected. However, at the weight bearing tibia as compared with the radius, the deleterious effects, especially on cortical bone, seem to be attenuated. TRIAL REGISTRATION NUMBER: NCT05426512, 21/06/2022, "retrospectively registered".