Management of primary and renal hyperparathyroidism: guidelines from the German Association of Endocrine Surgeons (CAEK)

Primary Hyperparathyroidism: An Analysis Amid the Co-Occurrence of Type 2 Diabetes Mellitus

BACKGROUND

Apart from classical elements in primary hyperparathyroidism (PHPT), non-classical complications, including type 2 diabetes mellitus (T2DM), are reported in some patients, but currently, they do not represent a parathyroidectomy (PTx) indication.

OBJECTIVE

to explore the latest data regarding glucose profile, particularly, T2DM and metabolic syndrome (MetS) in PHPT, including post-PTx.

METHODS

PubMed-based review included English-published original studies between January 2020 and December 2024 (n = 20).

RESULTS

Studied population: 764,485 subjects (female-to-male ratio of 1.26:1; 23,931 were PHPT patients vs. 740,502 controls). T2DM prevalence (n = 13; N = 763,645 patients; 55.92% females): 4-60% (higher vs. controls); for the largest study (N = 699,157) of 31.3%. Age-based analysis: higher T2DM prevalence at >50 vs. <50 years (14.4% vs. 2.6%, p < 0.001), but not all studies agreed. Concurrent vitamin D deficiency as a contributor to a higher risk had limited evidence. The association MetS-PHPT (n = 2) had no clear conclusion. Post-PTx showed the following: lower glycaemia, fasting insulin, insulin resistance (HOMA-IR) improvement, and reduced rate (but not all studies agreed). PHPT patients with prediabetes might represent the population sub-group with the highest post-PTx benefit.

CONCLUSIONS

The panel of PHPT-T2DM interplay remains heterogeneous. Data regarding post-PTx improvement of glucose disorders are still conflicting, recent findings suggested that surgery has beneficial effects, especially in patients with confirmed pre-existing prediabetes. Patients with the normocalcemic variant seemed to be less affected by the glucose-related disturbances, but further studies are needed. A better understanding of the intricate relationship between PHPT and glucose metabolism anomalies will help in providing optimal management to reduce the overall disease burden.

Comparative analysis of surgical versus medical treatment in non-localized primary hyperparathyroidism: renal and skeletal outcomes

Primary hyperparathyroidism (PHPT) presents diverse phenotypic variations. Few studies have investigated potential peculiarities of non-localized PHPT. This retrospective study aimed to compare renal and skeletal outcomes in patients with non-localized PHPT subjected to medical versus surgical treatment. Patients with non-localized PHPT from two European Tertiary Centers were divided into Group A (medical treatment, 42 patients) and Group B (Surgery, 45 patients). Biochemical markers, renal function, and bone mineral density (BMD) were assessed at baseline and 18-24 months post-treatment. At initial univariate analysis, Student's t test, Fisher's exact test, Wilcoxon test, and Friedman's non-parametric test were utilized. The two groups displayed significant differences in age and vitamin D levels. Group B exhibited notable post-operative reductions in serum calcium (p value < 0.00001, versus p < 0.001 for group A), PTH (p < 0.00001 versus 0.078 for group A), and calciuria (p < 0.05 versus 0.3657 for group A). Surgical intervention yielded significant improvements in BMD (group B: p < 0.0001; group A: p = 0.3359) at femoral and lumbar sites, with no post-treatment fractures in Group B, contrasting with Group A (4 new fractures). The GFR of group A showed a statistically non-significant change with a p value of 0.631. Conversely, for the group B, the GFR displayed a statistically significant change (p < 0.001.). Surgical intervention in non-localized PHPT showcased distinct advantages in normalizing calcemia and PTH levels and improving skeletal metabolism. Although few significant differences in renal function were observed post-surgery, the apparent advantage of group B should be interpreted taking into account the different average ages of the two cohorts.

Effectiveness of Bilateral Internal Jugular Parathyroid Hormone Measurements in Optimizing Hyperparathyroidism Surgery Outcomes

Objective

This study aimed to assess the effectiveness of intraoperative parathyroid hormone (PTH) measurements from bilateral internal jugular veins (BIJVs) in determining parathyroid gland laterality during surgery for primary hyperparathyroidism (PHPT).

Study Design

Prospective cohort study.

Setting

Single tertiary care center, February 2021 to February 2023.

Methods

All patients underwent intraoperative BIJV PTH measurements during parathyroidectomy. Preoperative localization of abnormal parathyroid glands was performed using cervical ultrasound (USG) and sestamibi scans (MIBI). Receiver operating characteristic (ROC) analysis was performed to determine the best performance (sensitivity and specificity) for predicting parathyroid gland laterality.

Results

A total of 124 patients underwent surgery during the study. PTH measurements from BIJV successfully confirmed the laterality of parathyroid adenomas in 102 cases (82.3%, P = .001). Intraoperative BIJV PTH measurements proved to be the most effective method for determining parathyroid gland laterality, with an accuracy of 82.3%. ROC curve analysis identified an optimal cutoff point of 16.7% for the percentage difference between right and left BIJV PTH values. The area under the curve (AUC) was 0.882, indicating high diagnostic accuracy. This cutoff yielded a sensitivity of 76.5% and a specificity of 95.5%. Additionally, no patients experienced complications related to the internal jugular vein (IJV) procedure.

Conclusion

Intraoperative BIJV PTH measurement is a valuable adjunct in parathyroidectomy, improving localization and enhancing surgical outcomes in PHPT patients.

Adenoma weight: the only predictive factor for multiple gland disease in primary hyperparathyroidism

BACKGROUND

Predicting a multiple gland disease (MGD) in primary hyperparathyroidism (pHPT) remains challenging. This study aimed to evaluate predictive factors for MGD.

METHODS

A retrospective chart review was performed of 1211 patients with histologically confirmed parathyroid adenoma or hyperplasia between 2007-2016. Localization diagnostics, laboratory parameters, and the weight of the resected parathyroid glands were evaluated concerning their predictive value of a multiple-gland disease.

RESULTS

A number of 1111 (91.7%) had a single-gland disease (SGD), and 100 (8.3%) a multiple-gland disease (MGD). US and MIBI scans were comparable for either negative or positive adenoma localization and suspected MGD. While the PTH level was similar, the calcium level was higher in SGD (2.8 mmol/L versus 2.76 mmol/L, P=0.034). MGD had a significantly lower gland weight (0.78 g versus 0.31 g; P<0.001). A gland weight of 0.418 grams was a predictive factor for MGD with a sensitivity of 72% and a specificity of 66%.

CONCLUSIONS

Only the weight of the resected parathyroid adenoma was meaningful in predicting MGD. A cut-off value of 0.418 g can differentiate SGD from MGD.

Diagnostic Ability and Correlation of Digital 11C-Methionine PET/CT in Primary Hyperparathyroidism with Inconclusive Standard Imaging

Purpose

11C-Methionine PET/CT is a promising method for detecting parathyroid lesions in patients with primary hyperparathyroidism (PHPT). We aimed to determine the diagnostic ability and correlation of digital 11C-Methionine PET/CT for parathyroid lesions in patients with PHPT, particularly in cases where standard imaging methods yielded inconclusive results.

Methods

This retrospective analysis was conducted on patients diagnosed with PHPT who underwent digital 11C-Methionine PET/CT imaging because of ambiguous results on standard imaging work-up (99mTc-MIBI parathyroid scan and/or neck ultrasonography). Quantitative 11C-Methionine PET/CT parameters, including maximum standardized uptake value (SUVmax), mean SUV (SUVmean), peak SUV (SUVpeak), parathyroid methionine volume (PMV), and whole methionine uptake (WMU: PMV multiplied by SUVmean) were calculated with various thresholds, and their correlations with biochemical and pathologic parameters were investigated.

Results

This study included 22 consecutive patients (10 men and 12 women) with a median age of 64.0 years. The lesion detection rate and sensitivity of digital 11C-Methionine PET/CT were 81.8% (18/22) and 100.0% (18/18), respectively. Quantitative analysis revealed that serum PTH (r = 0.490, P = 0.039) and serum calcium (r = 0.583, P = 0.011) were significantly correlated with PMV50%.

Conclusion

Digital 11C-Methionine PET/CT offers good performance in the detection of parathyroid lesions in PHPT patients with inconclusive standard imaging work-up. The volume parameter of PMV50% significantly correlated biochemical parameters and can serve as a complementary diagnostic tool.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13139-024-00878-x.

[Multimorbid patients in endocrine surgery]

Endocrine surgery in multimorbid, frail and geriatric patients is increasing, is often urgent and characterized by special risk constellations. Successful parathyroid gland surgery nearly always results in a marked improvement, irrespective of the specific risk profile of the patient. Except for critical intubation and mediastinal interventions in the risk profile, surgery of the thyroid glands is predominantly beneficial and justifiable even in frail patients. For surgery of the adrenal glands and for gastroenteropancreatic neuroendocrine tumors (GEP-NET), the expected extension of resection, the underlying disease or the grading are decisive for whether alternative treatment measures or surveillance appear to be more beneficial for patients at risk.

The detection of pathological parathyroid glands is facilitated by identifying vascular features on ultrasound: the potential benefit of a low-frequency vascular probe

PURPOSE

To evaluate the potential benefit of adding a low frequency vascular probe to the conventional pre-operative ultrasound examination of patients with primary hyperparathyroidism.

METHODS

A prospective cohort of 136 patients with primary hyperparathyroidism underwent a conventional ultrasound examination of the neck with a high frequency ( > 10 MHz) linear ultrasound probe, followed by an add-on examination with a low frequency vascular probe. For each ultrasound probe, and for every potential parathyroid lesion, the presence of a feeding vessel, a polar placement of the feeding vessel, and the presence of a vascular arch was recorded.

RESULTS

A total of 146 ultrasound lesions were evaluated for vascularity by each probe. For both ultrasound probes, the odds of a hyperfunctioning parathyroid gland being correctly identified increased with the number of visible vascular features. The vascular probe identified a significantly higher number of vascular features among ultrasound true positive glands compared with the conventional probe (p < 0.0001). Among histopathologically verified pathological parathyroid glands, the vascular probe identified 20% more feeding vessels, 27% more polar placements of the feeding vessel, and 65% more vascular arches than the high frequency probe. However, the diagnostic confidence score for true positive glands did not differ significantly between the probes (p = 0.11).

CONCLUSION

The addition of a low frequency vascular probe increases the number of visible vascular features in hyperfunctioning parathyroid glands, which facilitates their preoperative detection. Whether or not this can increase the diagnostic confidence of ultrasound examiners has yet to be substantiated.

Bone Mineral Density and First Line Imaging with [18F]fluorocholine PET/CT in Normocalcemic and Hypercalcemic Primary Hyperparathyroidism: Results from a Single Center

Objectives: Primary hyperparathyroidism (PHPT) is associated with normal or elevated calcium levels and affects bone mineral density. The proportion of cases predisposed to metabolic bone disease is unknown in patients with PHPT. The aim of this study was to assess bone mineral density and bone quality in patients with normo- or hypercalcemic primary hyperparathyroidism undergoing baseline parathyroid gland assessment with [18F]fluorocholine PET/CT imaging. Methods: A total of 140 consecutive patients were enrolled in this observational study. All patients with normo- or hypercalcemic primary hyperparathyroidism underwent dual-energy X-ray absorptiometry (DXA) for assessment of bone mineral density (BMD) and trabecular bone score (TBS). [18F]fluorocholine PET/CT was performed in all patients for the detection and localization of parathyroid adenoma. Hyper- and normocalcemic patients were compared with regard to the proportion of osteoporosis and osteopenia, T-Score, TBS, serum calcium, phosphorus and parathyroid hormone levels, the maximum standardized uptake value (SUVmax) in PET/CT imaging, and laboratory results. Results: The majority of patients was female (88.57%) and had a pathologic bone mineral density (52.86%). Overall, 33 patients had osteoporosis and 41 osteopenia. The mean lumbar T-Score was -1.48 (SD 1.37) and the T-Score of the femoral neck was -1.21 (SD 0.92). Mean TBS was also decreased (-2.13). No difference was found between normo- or hypercalcemic patients regarding bone metabolism and imaging parameters. Conclusions: More than half of patients with normo- or hypercalcemic PHPT showed abnormal BMD. First-line [18F]fluorocholine PET/CT identified parathyroid adenoma in a high proportion of patients, even in patients with normocalcemic PHPT. The early evaluation of metabolic bone disease seems desirable in clinical management of females with PHPT.

Temporal research trends in parathyroid surgery

BACKGROUND

Progress has been observed in the pathophysiology of calcium homeostasis, localization studies, and intraoperative adjuncts in parathyroid surgery. The aim of this study is to gain a comprehensive perspective on the research landscape of parathyroid surgery over time.

METHODS

A search of the Web of Science Core Collection was conducted to identify publications on parathyroid surgery from 1985 to 2024. Keywords were manually curated, and their frequencies were calculated based on the publication year.

RESULTS

Publications on secondary hyperparathyroidism have decreased in recent years, but those on calcimimetics, tertiary hyperparathyroidism, and parathyroid cancer have increased. Publications related to sestamibi scans have decreased, while research on four-dimensional computed tomography and positron emission tomography has increased. Research on fluorescence and ablation treatment has recently been on the rise. The citation count per publication was positively correlated with the number of contributing institutions.

CONCLUSION

We provide an overview of contemporary research themes and emerging topics related to parathyroid surgery. The endocrine surgery community could benefit from more inter-institutional partnerships to foster scientific progress.

Canadian Association of Radiologists Head and Neck Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Head and Neck Expert Panel consists of radiologists, a laryngologist and laryngeal surgeon, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 11 clinical/diagnostic scenarios, a systematic rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 17 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 26 recommendation statements across the 11 scenarios. This guideline presents the methods of development and the referral recommendations for sinus disease, tinnitus, thyroid and parathyroid disease, neck mass of unknown origin, acute sialadenitis, chronic salivary conditions, and temporomandibular joint dysfunction.

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.

Calcium/phosphate ratio: an additional tool for the clinical management of asymptomatic primary hyperparathyroidism?

PURPOSE

Serum calcium/phosphate ratio (Ca/P) has been recently proposed as an additional tool to identify primary hyperparathyroidism (PHPT), especially in patients with subclinical presentation, with a proposed cut-off of 3.3 when both values are expressed in mg/dL. No data are available on the relationship between Ca/P and the clinical presentation of PHPT. We thus evaluated this relationship in a large, single-center, unselected series.

METHODS

515 consecutive PHPT patients (mean age 65 ± 13.15 years, 77.1% females) were retrospectively evaluated at diagnosis.

RESULTS

Mean Ca/P was 4.54 ± 1.5 (range 2.36-13.9), being higher than 3.3 in 88.5% of patients. Ca/P was significantly higher in (1) males, (2) symptomatic PHPT, (3) patients with 25-hydroxy vitamin D levels lower than 20 μg/L, (4) patients with osteitis fibrosa cystica, (5) patients with T score < - 2.5 at the radial site. In a multivariate regression analysis, Ca/P resulted significantly associated with PTH levels. After the exclusion of 57 patients with asymptomatic PHPT (aPHPT) patients and serum Ca higher than 1 mg/dL above the upper limit of normal range, no differences were found in Ca/P between aPHPT meeting or not surgical criteria.

CONCLUSIONS

In PHPT Ca/P ratio is associated with increased biochemical and clinical severity of disease and represents a direct indicator of clinical bone damage. However, it does not seem an additional tool to identify aPHPT patients reaching surgical indication.

Regional variations in the management of primary hyperparathyroidism in Sweden: population-based case-control study

BACKGROUND

Substantial disparities in the utilization of parathyroidectomy for primary hyperparathyroidism have been reported. This study aimed to analyse regional variations in parathyroidectomy incidence with respect to the patient's disease burden and socioeconomic status.

METHODS

A population-based case-control study included all patients with primary hyperparathyroidism who underwent parathyroidectomy in Sweden between 2008 and 2017 and 10 matched controls. Data on demographic and socioeconomic variables, co-morbidities and drug prescriptions were collected from relevant national registers. Conditional logistic regression was used to analyse predictors of parathyroidectomy.

RESULTS

A total of 8626 patients with primary hyperparathyroidism (77% women) underwent parathyroidectomy during the study interval. The annual incidence of parathyroidectomy was 9.0 per 100 000 persons. The annual age-adjusted regional incidences of parathyroidectomy varied between 3.3 and 16.9 operations per 100 000 inhabitants. Except for a small underrepresentation of patients with lower education, no effect of socioeconomic variables was observed. Compared with matched controls, the parathyroidectomy group had increased odds ratios of having developed classical symptoms of primary hyperparathyroidism and being prescribed medication against cardiovascular disorders and psychiatric illness at the time of parathyroidectomy. Increased risks of kidney stones and osteoporosis were observed 5 years before parathyroidectomy. Patients with primary hyperparathyroidism selected for parathyroidectomy from regions with a low incidence of operations had a higher prevalence of kidney stones, osteoporosis and hypertension, as well as larger adenomas and higher calcium levels at the time of parathyroidectomy compared with patients in high-incidence regions.

CONCLUSION

The considerable variation in parathyroidectomy seems more likely associated with different clinical thresholds for detection of primary hyperparathyroidism and referral to surgery than socioeconomic disparities.

Parathyroid Retrospective Analysis of Neoplasms Incidence (pTRANI Study): An Italian Multicenter Study on Parathyroid Carcinoma and Atypical Parathyroid Tumour

BACKGROUND

Parathyroid cancer (PC) is a rare sporadic or hereditary malignancy whose histologic features were redefined with the 2022 WHO classification. A total of 24 Italian institutions designed this multicenter study to specify PC incidence, describe its clinical, functional, and imaging characteristics and improve its differentiation from the atypical parathyroid tumour (APT).

METHODS

All relevant information was collected about PC and APT patients treated between 2009 and 2021.

RESULTS

Among 8361 parathyroidectomies, 351 patients (mean age 59.0 ± 14.5; F = 210, 59.8%) were divided into the APT (n = 226, 2.8%) and PC group (n = 125, 1.5%). PC showed significantly higher rates (p < 0.05) of bone involvement, abdominal, and neurological symptoms than APT (48.8% vs. 35.0%, 17.6% vs. 7.1%, 13.6% vs. 5.3%, respectively). Ultrasound (US) diameter >3 cm (30.9% vs. 19.3%, p = 0.049) was significantly more common in the PC. A significantly higher frequency of local recurrences was observed in the PC (8.0% vs. 2.7%, p = 0.022). Mortality due to consequences of cancer or uncontrolled hyperparathyroidism was 3.3%.

CONCLUSIONS

Symptomatic hyperparathyroidism, high PTH and albumin-corrected serum calcium values, and a US diameter >3 cm may be considered features differentiating PC from APT. 2022 WHO criteria did not impact the diagnosis.

Atypical parathyroid tumor: clinical and parathyroid hormone response to surgical treatment

Purpose

Primary hyperparathyroidism (PHPT) is caused by typical adenoma (TA), multiglandular disease (MD), or parathyroid carcinoma (PC), and in a smaller percentage of cases by atypical parathyroid tumor (APT). The objective of this study is the retrospective analysis of clinical features and parathyroid hormone (PTH)/calcium response to surgery in patients who underwent parathyroidectomy for symptomatic PHPT with histological evidence of APT.

Methods

We retrospectively reviewed our institutional experience in the management of PHPT from January 2016 to December 2021 focusing on those patients presenting APTs. We analyzed the clinical features of this disease and PTH/calcium response to surgical treatment in APTs compared to the other pathological conditions causing PHPT.

Results

In a cohort of 125 patients with PHPT we found 112 TAs (89.6%), 6 APTs (4.8%), 6 PCs (4.8%), and only 1 MD (0.8%). APTs in comparison to other parathyroid diseases showed peculiar features such as adhesion to the surrounding structures and a frequent intrathyroidal location, which may justify thyroid loboistmectomy adopted in most of the observed cases. APTs showed significantly higher preoperative PTH values compared to TA + MD and were relevant to PC.

Conclusion

Due to its rarity, there is a lack of specific indications in the management of APTs. Biochemical features observed in APT and PC can be related to similar biological behavior. However, some specific features observed preoperatively in some cases of PHPT might suggest presence of an APT, which could be helpful mostly in surgical and postoperative management. Further studies are required to confirm the results of the present preliminary report.

Neuroendocrine Parathyroid Tumors: Quality of Life in Patients with Primary Hyperparathyroidism

Tumors of the parathyroid glands, when associated with PTH (parathyroid hormone) excess, display a large area of complications; in addition to the classical clinical picture of primary hyperparathyroidism (PHP), a complex panel of other symptoms/signs can be identified, including memory and cognitive impairment, chronic asthenia/fatigue, reduced muscle functionality, depressive mood, non-specific bone pain, and loss of sleep quality. The perception of quality of life (QoL) can be supplementarily enhanced by their progressive onset, which makes many patients not be fully aware of them. Their improvement was reported very early after parathyroidectomy (PTx), yet the level of statistical evidence does not qualify these non-classical elements as standalone indications for PTx. Our objective is introducing an up-to-date on QoL scores with regards to the patients diagnosed with PHP, particularly taking into consideration PHP management from baseline to post-operatory outcome, including in cases with multiple endocrine neoplasia. This is a narrative review of literature. We revised full-length papers published in English through PubMed research conducted between January 2018 and May 2023 by using the key words "quality of life" and "primary hyperparathyroidism". We particularly looked at data on self-reported QoL (through questionnaires). We excluded from the search the studies focused on non-PTH related hypercalcemia, secondary, and/or renal/tertiary hyperparathyroidism, and vitamin D supplementation. Overall, we identified 76 papers and selected for the final analysis 16 original studies on QoL and PHP (a total of 1327 subjects diagnosed with syndromic and non-syndromic PHP). The studies with the largest number of individuals were of 92, 104, 110, 134, 159, as well as 191. A few cohorts (n = 5) were of small size (between 20 and 40 patients in each of them). Concerning the study design, except for 2 papers, all the mentioned studies provided longitudinal information, particularly the timeframe from baseline (before PTx) and after surgery. The post-operatory follow-up was of 3-6 months, but mostly between 1 and 3 years (maximum a decade of surveillance). The age of the patients varies between medians of 56, 62, 64, and 68 years. Most frequent questionnaires were SF-36, PHPQoL, and PAS. Despite not being unanimously similar, an overall reduced score of QoL in patients with PHP versus controls was registered, as well as general improvement following PTx. Variations of QoL results might have a multifactorial background from different comorbidities, studied populations, technical aspects of collecting the data, etc. QoL scores in PHP represents a complex heterogeneous picture, from their correlation with clinical features and lab assays (e.g., the level of serum calcium), the associated comorbidities (such as multiple endocrine neoplasia syndromes), up to the assessment of the QoL improvement after parathyroidectomy (PTx). While current studies do not unanimously agree on each QoL domain, the assessment of QoL might represent a supplementary argument to consider when deciding for PTx, especially in asymptomatic cases and in patients who do not fit into well-known categories of surgery candidates, according to current guidelines, thus assessing QoL in PHP is part of a current research gap. QoL evaluation in PHP remains an open issue, towards which awareness should be cultivated by both endocrinologists and surgeons. The introduction of a routine evaluation of the QoL scores in patients, as well as the selection of the most appropriate questionnaire(s), represents an open chapter thus awareness in mandatory.

[Current approach in cases of persistence and recurrence of primary hyperparathyroidism]

Primary hyperparathyroidism (pHPT) is now diagnosed much earlier and is often asymptomatic. Biochemically mild pHPT is characterized by small parathyroid adenomas (NSDA) and the results of localization diagnostics as well as surgical treatment are poorer. The frequency of redo surgery is 3-14% in large registries. The planning of a reoperation is no different from the basic principles for the first intervention. Diagnosis and differential diagnoses must be checked. This is followed by a review of the first operation and the associated histology as well as imaging and the course of parathyroid hormone (PTH) values. The next step is to check whether the reoperation is necessary. Most patients still have comprehensible indications that correspond to the guidelines and also ex-post. In contrast to the first intervention, there is always a need to attempt to localize the NSDA. The first procedure is a surgically performed ultrasound. Other localization options are MIBI-SPECT scintigraphy, 4D-CT and FEC-PET-CT, with the latter having the highest sensitivity. There is a clear relationship between higher case numbers and better surgical outcomes. Personal experience is decisive and in terms of predicting success this is even more important than the results of localization procedures. The goal of maximizing the outcome and minimizing morbidity justifies what is from the perspective of those affected probably the most important requirement for the future: no redo surgery for HPT outside of a high-volume center.

[Current indications and operative strategy for renal hyperparathyroidism]

BACKGROUND

Renal hyperparathyroidism results from pathophysiologic changes induced and maintained by terminal renal failure. Surgical treatment is possible using various resection strategies.

AIM OF THE WORK (RESEARCH QUESTION)

The aim of this work is to illustrate the indications, techniques and resection strategies for surgical treatment of renal hyperparathyroidism.

MATERIAL AND METHODS

National and international guidelines regarding the surgical treatment of renal hyperparathyroidism were analyzed. Furthermore, our own practical experience was integrated into the article.

RESULTS

While the indications for surgery according to the Surgical Working Group Endocrinology (CAEK) guidelines are given in cases of clinical impairment and renal hyperparathyroidism that cannot be controlled by medication, international guidelines additionally refer to the absolute parathyroid hormone level for deciding for surgery.

DISCUSSION

Individual patient consultation is necessary in the case of renal hyperparathyroidism in order to determine the right time for surgical treatment as well as the most suitable surgical technique, taking into account the individual risk profile and other therapeutic perspectives, including renal transplantation.

[Outpatient parathyroid gland operations in the German system-Feasible and useful?]

BACKGROUND

In 2019 approximately 7500 procedures were carried out for parathyroid diseases in Germany (Statistisches Bundesamt 2020, https://www.destatis.de/DE/ ). All operations were performed as inpatient procedures. The catalogue of outpatient procedures for 2023 does not include operations on the parathyroid glands.

OBJECTIVE

Which conditions are prerequisites for parathyroid surgery on an outpatient basis?

MATERIAL AND METHODS

Published data on outpatient parathyroid surgery were analyzed with respect to the underlying disease, procedures performed and patient-specific circumstances.

RESULTS

Initial operations for localized sporadic primary hyperparathyroidism (pHPT) seem to be suitable for outpatient surgery, provided that affected patients fulfil the general prerequisites for an outpatient operation. The procedures focused parathyroidectomy and unilateral exploration can be carried out using local or general anesthesia and have a very low risk for postoperative complications. The organization of the day of the operation and the postoperative treatment of the patient should be organized within a detailed standard of procedure. The remuneration for an outpatient parathyroidectomy is not included in the German outpatient surgery catalogue and is therefore currently not adequately financially reimbursed.

CONCLUSION

In selected patients a limited initial intervention for primary hyperparathyroidism can be safely performed on an outpatient basis; however, the present German reimbursement modalities have to be revised so that the cost of these outpatient operations can be adequately covered.

[Surgery of hyperparathyroidism]

The surgical removal of diseased parathyroid glands is the only curative treatment for primary and secondary hyperparathyroidism. Before an intervention, the confirmed diagnosis and an accurate localization are decisive for selection of the appropriate procedure. After appropriate localization diagnostics, a focussed intervention is possible for primary hyperparathyroidism, whereby every intervention must be controlled by intraoperative monitoring of parathyroid hormone. Reoperations or multiple glandular disease necessitate a differentiated approach with appropriate prior diagnostics.

Surgery for primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a hypercalcemic disorder that occurs when one or more parathyroid glands produces excessive parathyroid hormone (PTH). PHPT is typically treated with surgery, and it remains the only definitive therapy, whose techniques have evolved over previous decades. Advances in preoperative localization exams and the intraoperative PTH monitoring have become the cornerstones of recent parathyroidectomy techniques, as minimally invasive techniques are appropriate for most patients. Nevertheless, these techniques, are not suitable for PHPT patients who are at risk for multiglandular disease, especially in those who present with familial forms of PHPT that require bilateral neck exploration. This manuscript also explores other conditions that warrant special consideration during surgical treatment for PHPT: normocalcemic primary hyperparathyroidism, pregnancy, reoperation for persistent or recurrent PHPT, parathyroid carcinoma, and familial and genetic forms of hyperparathyroidism.

A predictive risk score to diagnose hypocalcemia after parathyroidectomy in patients with secondary hyperparathyroidism: a 22-year retrospective cohort study

Hypocalcemia is a common complication found in patients with secondary hyperparathyroidism (SHPT) who undergo parathyroidectomy. This study aimed to construct a predictive risk score for the occurrence of hypocalcemia after parathyroidectomy in patients with SHPT who underwent chronic renal replacement therapy (RRT). This 22-year retrospective cohort study enrolled 179 patients with SHPT who had their first parathyroidectomy. Eighty-two percent of patients developed hypocalcemia within 16.9 (95% CI 14.5–19.5) h after parathyroidectomy. This study demonstrated four factors as independent risk factors for post-parathyroidectomy hypocalcemia, including duration of RRT, preoperative serum phosphate, preoperative serum alkaline phosphatase (ALP) and mean difference of serum intact parathyroid hormone (iPTH). By using logistic regression analysis, this study demonstrated cut-off points for these four risk factors for the diagnosis of hypocalcemia after parathyroidectomy: 5 years for the duration of RRT, 5 mg/dL for serum phosphate, 387 U/L for serum ALP, and 97% for the mean difference of serum iPTH. Finally, the predictive risk score was constructed by assigning a score of one to each factor. With a total score of at least 2, the proposed predictive risk score has an AuROC of 0.755 with a sensitivity of 78.2%, a specificity of 71.4%, and an accuracy of 76.9%.

An essential practice summary of the new EANM guidelines for parathyroid imaging

Parathyroid imaging is essential for the detection and localization of hyperfunctioning parathyroid tissue in patients with primary hyperparathyroidism (pHPT). Surgical treatment of pHPT mainly consists of minimally invasive parathyroidectomy (MIP), as a single adenoma represents the most common cause of this endocrine disorder. Successful surgery requires an experienced surgeon and relies on the correct preoperative detection and localization of hyperfunctioning parathyroid glands. Failure to preoperatively identify the culprit parathyroid gland by imaging may entail a more invasive surgical approach, including bilateral open neck exploration, with higher morbidity compared to minimally invasive parathyroidectomy. Parathyroid imaging may be also useful before surgery in case of secondary hyperparathyroidism (sHPT) or hereditary disorders (MEN 1, 2, 4) as it enables correct localization of typically located parathyroid glands, detection of ectopic as well as supernumerary glands. It is now accepted by most surgeons experienced in parathyroid surgery that preoperative imaging plays a key role in their patients' management. Recently, the European Association of Nuclear Medicine (EANM) issued an updated version of its Guidelines on parathyroid imaging. Its aim is to precise the role and the advantages and drawbacks of the various imaging modalities proposed or well established in the preoperative imaging strategy. It also aims to favor high performance in indicating, performing, and interpreting those examinations. The objective of the present article is to offer a summary of those recent EANM Guidelines and their originality among other Guidelines in this domain issued by societies of nuclear medicine physicians or other disciplines.

Minimally invasive video-assisted parathyroidectomy (MIVAP) versus conventional parathyroidectomy for renal hyperparathyroidism: a retrospective multicenter study

To compare minimally invasive video-assisted parathyroidectomy (MIVAP) versus conventional surgery for renal hyperparathyroidism (rHPT). Between 2006 and 2020, 53 patients underwent MIVAP and 182 underwent conventional parathyroidectomy for rHPT at the Kliniken Essen-Mitte and Knappschaftskrankenhaus Bochum, respectively. Two propensity score-matched groups were retrospectively analyzed: the MIVAP group (VG; n = 53) and the conventional group (CG; n = 53). To assess long-term results, the patients were questioned prospectively (VG; n = 17, and CG; n = 26). The VG had a smaller incision (2.8 vs. 4.8 cm), shorter operation duration (81.0 vs. 13.9 min), and shorter duration of stay (2.4 vs. 5.7 days) (p < 0.0001) but a smaller drop in parathyroid hormone (PTH) postoperatively (81.3 vs. 85.5%. p = 0.022) than the CG. The conversion rate was 9.4% (n = 5). The VG had better Patient Scar Assessment Scale (PSAS) scores (10.8 vs. 11.7 p = 0.001) but worse SF-12 health survey scores (38.7 vs. 45.8 for physical health and 46.7 vs. 53.4 for mental health) (p < 0.0001). The PTH level at follow-up was higher in the VG (162.7 vs. 59.1 ng/l, p < 0.0001). There were no differences in morbidity, number of removed parathyroid glands, disease persistence, late rHPT relapse and need for repeat surgery between groups. MIVAP was superior to conventional parathyroidectomy regarding aesthetic outcomes and cost effectiveness. Conventional surgery showed better control of PTH levels and health scores on follow-up than MIVAP, without any impact on rHPT relapse and need for repeat surgery.

Trail registration number and date of registration: DRKS00022545 on 14.12.2020.

Preoperative Imaging with [18F]-Fluorocholine PET/CT in Primary Hyperparathyroidism

Primary hyperparathyroidism (pHPT) is a common endocrine disorder due to hyperfunctioning parathyroid glands. To date, the only curing therapy is surgical removal of the dysfunctional gland, making correct detection and localization crucial in order to perform a minimally invasive parathyroidectomy. ¹⁸F-Fluorocholine positron emission tomography/computed tomography (¹⁸F-FCH PET/CT) has shown promising results for the detection of pHPT, suggesting superiority over conventional imaging with ultrasounds or scintigraphy. A total of 33 patients with pHPT who had negative or equivocal findings in conventional imaging received ¹⁸F-FCH PET/CT preoperatively and were retrospectively included. A pathological hyperfunctional parathyroid gland was diagnosed in 24 cases (positive PET, 72.7%), 4 cases showed equivocal choline uptake (equivocal PET, 12.1%), and in 5 cases, no enhanced choline uptake was evident (negative PET, 15.2%). Twelve of the twenty-four detected adenoma patients underwent surgery, and in all cases, a pathological parathyroid adenoma was resected at the site detected by PET/CT. Two of the six patients without pathological choline uptake who received a parathyroidectomy revealed no evidence of parathyroid adenoma tissue in the histopathological evaluation. This retrospective study analyzes ¹⁸F-FCH PET/CT in a challenging patient cohort with pHPT and negative or equivocal conventional imaging results and supports the use of ¹⁸F-FCH for the diagnosis of hyperfunctional parathyroid tissue, especially in this patient setting, with a 100% true positive and true negative detection rate. Our study further demonstrates the importance of ¹⁸F-FCH PET/CT for successful surgical guidance.

The Effect of the Frequently Used Cinacalcet for pHPT during the COVID-19 Pandemic on Perioperative Decrease in Parathyroid Hormone

Background: Cinacalcet is a calcimimetic drug that has increasingly been used as a bridging therapy for primary hyperparathyroidism (pHPT), especially during the COVID-19 pandemic. The aim of our study was to investigate if preoperative cinacalcet therapy affects intraoperative parathyroid hormone (IOPTH) monitoring during parathyroidectomy, which is an important indicator for the success of surgery. Methods: In this single-center retrospective analysis, we studied the outcomes of 72 patients who underwent surgery for pHPT. We evaluated two groups: those with cinacalcet therapy before operation—the cinacalcet group (CG)—and those without medical therapy preoperatively (non-CG). In order to perform a between-group comparison of time trends, we fit a linear mixed-effects model with PTH as the response variable and predictors PTH levels preoperatively, group (cinacalcet yes/no), time, the group-by-time interaction, and a random intercept (per subject). Results: Our cohort included 51 (71%) women and 21 (29%) men, who were operated upon for pHPT in the period from January 2018 until August 2021. All patients were diagnosed with pHPT and 54% of the cohort were symptomatic for hypercalcemia. Moreover, 30% of the patients were treated with cinacalcet as a bridging therapy preoperatively, and this increased during the COVID-19 pandemic, as 64% of this group were treated in the last two years. Calcium values were significantly different before (p < 0.001) and after (p = 0.0089) surgery, but calcium level change did not differ significantly between the CG and non-CG. Parathyroid hormone (PTH) levels dropped significantly in both groups during 10 min IOPTH monitoring (p < 0.001), but there was no significant difference between the two groups (p = 0.212). Conclusions: In the examined patient cohort, the use of cinacalcet did not affect the value of IOPTH monitoring during surgery for pHPT.

18F-Fluorocholine-PET combined with contrast-enhanced CT for localizing hyperfunctioning parathyroid glands and optimizing surgical treatment in patients with hyperparathyroidism

PURPOSE

Hyperparathyroidism (HPT) is a common disorder. A cure can only be achieved by removing all diseased glands. It is critical to localize the hyperfunctioning glands exactly to prevent extensive surgical exploration. The number of false negative/inconclusive results in standard imaging techniques is high. We aimed to evaluate the diagnostic accuracy of ¹⁸F-Fluorocholine-PET in combination with contrast-enhanced CT (FCH-PET/CT) and its sensitivity in patients with primary, secondary/tertiary, and familial HPT with negative and/or discordant findings in ultrasound and/or ^99mTc-sestamibi scintigraphy/SPECT/CT.

METHODS

A total of 96 patients with HPT and negative/equivocal conventional imaging were referred for FCH-PET/CT. In this retrospective, single institution study, 69 patients, who have undergone surgery and histopathologic workup, were analyzed. Of the 69 patients included, 60 patients suffered from primary HPT, four from secondary or tertiary HPT, and five from familial HPT. Sensitivities, positive predictive values, and accuracies were calculated.

RESULTS

Sensitivity/positive predictive value (PPV) per lesion was 87.5/98.3% for primary HPT, 75/100% for secondary/tertiary HPT and 25/66.7% for familial HPT. Sensitivity/PPV per patient was 91.5/98.2% for primary HPT, 100/100% for secondary/tertiary HPT and 50/100% for familial HPT. All patients showed normalized serum calcium levels in the postoperative period. The follow-up rate was 97%. Of the patients included in the study, 58 of 60 patients with primary HPT, and four of four patients with secondary/tertiary HPT showed normal calcium and parathyroid hormone (PTH) levels after six months and were cured. Of the patients with familial HPT, four of five patients were cured.

CONCLUSION

Diagnostic accuracy of ¹⁸F-Fluorocholine-PET/CT for patients with pHPT is excellent. ¹⁸F-Fluorocholine-PET/CT is a valuable tool for endocrine surgeons to optimize the surgical treatment of patients with hyperparathyroidism.

Serum Phosphate: A Neglected Test in the Clinical Management of Primary Hyperparathyroidism

BACKGROUND

Although the inverse correlation between serum PTH and phosphate (P) levels in patients with primary hyperparathyroidism (PHPT) is well known, the relationship between P levels and the clinical picture of the disease has not been well investigated. This was thus the aim of this paper.

PATIENTS

A total of 472 consecutive patients with PHPT attending our center were retrospectively evaluated at diagnosis.

RESULTS

P levels lower than 2.5 mg/dL (HypoP) were found in 198/472 patients (41.9%). HypoP was mild (2-2.5 mg/dL), moderate (1-1.9 mg/dL), and severe (<1 mg/dL) in 168 (84.9%), 30 (15.1%), and 0 cases, respectively. P levels were lower in males than females. Patients with more severe bone density impairment at the radial (but not the vertebral or femoral) site had P levels significantly lower than other patients. PHPT severity was worse in HypoP patients, both clinically (higher prevalence of renal stones, but not of osteoporosis) and biochemically (higher serum calcium and PTH levels). All patients in the moderate HypoP group were either symptomatic or asymptomatic reaching surgical indication according to the latest guidelines.

CONCLUSIONS

We observed a relationship between P levels and biochemical and clinical features of PHPT severity. In asymptomatic PHPT patients, even moderate HypoP is predictive of surgical indication, regardless of age and hypercalcemia severity.

Questionable value of [99mTc]-sestamibi scintigraphy in patients with pHPT and negative ultrasound

PURPOSE

A successful focused surgical approach in primary hyperparathyroidism (pHPT) relies on accurate preoperative localization of the parathyroid adenoma (PA). Most often, ultrasound is followed by [^99mTc]-sestamibi scintigraphy, but the value of this approach is disputed. Here, we evaluated the diagnostic approach in patients with surgically treated pHPT in our center with the aim to further refine preoperative diagnostic procedures.

METHODS

A single-center retrospective analysis of patients with pHPT from 01/2005 to 08/2021 was carried out followed by evaluation of the preoperative imaging modalities to localize PA. The localization of the PA had to be confirmed intraoperatively by the fresh frozen section and significant dropping of the intraoperative parathyroid hormone (PTH) levels.

RESULTS

From 658 patients diagnosed with pHPT, 30 patients were excluded from the analysis because of surgery for recurrent or persistent disease. Median age of patients was 58.0 (13-93) years and 71% were female. Neck ultrasound was carried out in 91.7% and localized a PA in 76.6%. In 23.4% (135/576) of the patients, preoperative neck ultrasound did not detect a PA. In this group, [^99mTc]-sestamibi correctly identified PA in only 25.4% of patients. In contrast, in the same cohort, the use of [¹¹C]-methionine or [¹¹C]-choline PET resulted in the correct identification of PA in 79.4% of patients (OR 13.23; 95% CI 5.24-33.56).

CONCLUSION

[¹¹C]-Methionine or [¹¹C]-choline PET/CT are superior second-line imaging methods to select patients for a focused surgical approach when previous ultrasound failed to identify PA.

[Medicolegal aspects of primary and renal hyperparathyroidism]

BACKGROUND

Compared with malpractice claims in thyroid surgery, expert medico-legal reviews of surgery performed for hyperparathyroidism (HPT) that aim to prove or rebut surgical malpractice are rare. The aim of this analysis was to describe typical risk patterns for possible treatment errors and to generate recommendations for avoiding these treatment errors.

MATERIAL AND METHODS

A total of 12 surgical expert medico-legal reviews, which were carried out by order of 9 arbitration boards and 3 courts between 1997 and 2020 were evaluated.

RESULTS

If the indications for surgical treatment of hyperparathyroidism were present, the failure to identify a parathyroid adenoma or hyperplastic parathyroid glands was in the majority of cases not rated as a surgical treatment error, especially in atypical localizations. Unilateral recurrent laryngeal nerve palsy and postoperative bleeding cannot always be prevented, despite maximum diligence. In contrast, bilateral recurrent laryngeal nerve palsy can be prevented when intraoperative neuromonitoring is correctly applied. A lack of patient information regarding postoperatively persistent HPT, postoperative hypoparathyroidism following the removal of inconspicuous parathyroid glands and nonindicated lobectomy or total thyroidectomy, mostly performed under the assumption of an intrathyroid parathyroid adenoma, represented avoidable malpractice issues.

CONCLUSION

Advanced knowledge of the pathophysiology of the disease and the anatomy of the parathyroid glands as well as the establishment of intraoperative and perioperative standards can prospectively greatly reduce avoidable errors in the surgical treatment and postoperative care of HPT.