A decade of change in the uptake of parathyroidectomy in England and Wales

Epidemiology, Pathophysiology, and Genetics of Primary Hyperparathyroidism

In this narrative review, we present data gathered over four decades (1980-2020) on the epidemiology, pathophysiology and genetics of primary hyperparathyroidism (PHPT). PHPT is typically a disease of postmenopausal women, but its prevalence and incidence vary globally and depend on a number of factors, the most important being the availability to measure serum calcium and parathyroid hormone levels for screening. In the Western world, the change in presentation to asymptomatic PHPT is likely to occur, over time also, in Eastern regions. The selection of the population to be screened will, of course, affect the epidemiological data (ie, general practice as opposed to tertiary center). Parathyroid hormone has a pivotal role in regulating calcium homeostasis; small changes in extracellular Ca++ concentrations are detected by parathyroid cells, which express calcium-sensing receptors (CaSRs). Clonally dysregulated overgrowth of one or more parathyroid glands together with reduced expression of CaSRs is the most important pathophysiologic basis of PHPT. The spectrum of skeletal disease reflects different degrees of dysregulated bone remodeling. Intestinal calcium hyperabsorption together with increased bone resorption lead to increased filtered load of calcium that, in addition to other metabolic factors, predispose to the appearance of calcium-containing kidney stones. A genetic basis of PHPT can be identified in about 10% of all cases. These may occur as a part of multiple endocrine neoplasia syndromes (MEN1-MEN4), or the hyperparathyroidism jaw-tumor syndrome, or it may be caused by nonsyndromic isolated endocrinopathy, such as familial isolated PHPT and neonatal severe hyperparathyroidism. DNA testing may have value in: confirming the clinical diagnosis in a proband; eg, by distinguishing PHPT from familial hypocalciuric hypercalcemia (FHH). Mutation-specific carrier testing can be performed on a proband's relatives and identify where the proband is a mutation carrier, ruling out phenocopies that may confound the diagnosis; and potentially prevention via prenatal/preimplantation diagnosis. © 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).

Parathyroid scintigraphy

The purpose of this guideline is to assist specialists in Nuclear Medicine and Radionuclide Radiology in recommending, performing, interpreting and reporting the results of Parathyroid Scintigraphy. This guideline will assist individual departments to formulate their own local protocols. This does not aim to be prescriptive regarding technical aspects of individual camera acquisitions which need to be developed in conjunction with the local medical physics expert. These guidelines pertain only to adult patients. There are numerous techniques for localizing Parathyroid adenomas. This guideline will describe the use of 99mTc-sestamibi dual phase imaging which may be used alone or in combination with other modalities.

The surgical management of sporadic primary hyperparathyroidism

Sporadic primary hyperparathyroidism (pHPT) is the commonest cause of hypercalcaemia in the ambulatory population. It has a female preponderance and its incidence is increasing. In 85% of cases it is caused by a single parathyroid adenoma, with four gland hyperplasia in up to 20%. Parathyroidectomy is the only cure and bilateral neck exploration remains the gold standard to achieve this. Several adjuncts have been developed to improve success rates or limit the extent of surgery. Pre-operative localisation permits planned targeted surgery. Ultrasound scanning and scintigraphy are the most commonly employed, although 4DCT has become a useful modality in complex cases. However, excellent rates of biochemical cure can be achieved in specialist centres when pre-operative imaging is negative. Pre-operative prediction models and intra-operative parathyroid hormone (ioPTH) assist, with high sensitivity, to predict single gland disease. Reoperations present a major challenge to the endocrine surgeon.

Primary hyperparathyroidism: findings from the retrospective evaluation of cases over a 6-year period from a regional UK centre

BACKGROUND

Although there are international guidelines on diagnosis and management of primary hyperparathyroidism (PHPT), clinical practice varies in different centres. Periodic review of diagnostic work-up, surgical treatment by parathyroidectomy (PTX) and clinical surveillance in nonsurgical treatment group among patients with PHPT is expected to improve the quality of care. We report a retrospective study of cases with PHPT managed at a regional centre in the United Kingdom.

METHODS

Clinical data of cases with calcium ≥2.6 mmol/L and parathyroid hormone (PTH) ≥9.0 pmol/L was procured from biochemistry database from January 2011 to December 2016. Laboratory parameters, imaging studies for renal stones, osteoporosis and localisation of parathyroid adenomas, type of treatment received (PTX or nonsurgical), complications of treatment, other medical co-morbidities and mortality during follow-up was recorded in each case to examine the outcomes of care of patients with PHPT.

RESULTS

The study included 160 patients: 127 (79%) females and 33 (21%) males. Median age was 70 years in females and 74 in males. Thirty cases (19% of 159) had renal stones and 47 (37.3% of 126) had osteoporosis. Eighty-one cases (51%) received PTX. Logistic regression analysis showed that higher calcium levels (odds ratio (OR) = 73.991; p < 0.001), peak PTH (OR = 1.023; p = 0.025), peak alkaline phosphatase (OR = 0.985, p < 0.001), lower age (OR = 0.985, p < 0.001) and male gender (OR = 0.209, p < 0.002) as statistically significant predictors for patients receiving PTX. Higher age at diagnosis of PHPT was associated with increased risk of co-existent hypertension (OR = 10.904, p = 0.001) and fractures (OR = 1.067, p = 0.004). Higher peak calcium concentration was an independent predictor of acute kidney injury (OR = 9.631, p = 0.011). PTX cured 76 cases (94%) with only 7 (9%) postoperative complications. Twenty-four cases (15%) died from the entire cohort (only one from PTX group) during a median follow-up period of 3.6 years (interquartile range = 1.5).

CONCLUSIONS

PTX treatment is associated with cure of disease in patients with PHPT with acceptable risk of complications. Improvements in diagnostic work-up and follow-up care should improve the morbidity from PHPT.

Evaluation of the radiation dose exposure and associated cancer risks in patients having preoperative parathyroid localization

OBJECTIVE The study aimed to evaluate the total effective and organ absorbed radiation doses associated with three- and four-phase parathyroid computed tomography (CT) and sestamibi scans used for the preoperative localisation of parathyroid adenomas in a cohort of patients with primary hyperparathyroidism at a single institution. We aimed to assess the risk of cancer incidence for the organs demonstrating the highest absorbed doses for the different imaging techniques, and more specifically determine the risk for our cohort of patients. METHODS Fifty patients with primary hyperparathyroidism had both multiphase CT and sestamibi scans. The Imaging Performance Assessment of CT Scanners (ImPACT) calculator was used to estimate the patient-effective and organ-absorbed radiations doses for all the CT examinations. For sestamibi scans, the US Nuclear Regulatory Commission NUREG/CR-6345 publication was used to estimate the dose for each patient. The attributable risks of cancer were calculated using the Health Protection Agency HPA-CRCE-028 publication. RESULTS The mean patient total effective doses were 15.9% ± 2.8 mSv, 20.2% ± 2.8  mSv and 5.6 ± 0.24 mSv for three-phase CT, four-phase CT and sestamibi examinations, respectively. In our cohort, the highest attributable lifetime risk was for lung cancer (0.03%) after multiphase CT. This compared with a tenfold lower risk for thyroid cancer (0.003%). After sestamibi, the highest risk was for colon cancer (0.06%). CONCLUSIONS Multiphase CT is associated with a higher radiation dose and thus a higher potential risk of cancer, but this risk is low in the older population that constituted the majority of our cohort.

Trends in hospital admissions and surgical procedures for degenerative lumbar spine disease in England: a 15-year time-series study

OBJECTIVES

Low back pain (LBP), from degenerative lumbar spine disease, represents a significant burden on healthcare resources. Studies worldwide report trends attributable to their country's specific demographics and healthcare system. Considering England's specific medico-socioeconomic conditions, we investigate recent trends in hospital admissions and procedures for LBP, and discuss the implications for the allocation of healthcare resources.

DESIGN

Retrospective cohort study using Hospital Episode Statistics data relating to degenerative lumbar spine disease in England, between 1999 and 2013. Regression models were used to analyse trends.

OUTCOME MEASURES

Trends in the number of admissions and procedures for LBP, mean patient age, gender and length of stay.

RESULTS

Hospital admissions and procedures have increased significantly over the study period, from 127.09 to 216.16 and from 24.5 to 48.83 per 100,000, respectively, (p<0.001). The increase was most marked in the oldest age groups with a 1.9 and 2.33-fold increase in admissions for patients aged 60-74 and ≥ 75 years, respectively, and a 2.8-fold increase in procedures for those aged ≥ 60 years. Trends in hospital admissions were characterised by a widening gender gap, increasing mean patient age, and decreasing mean hospital stay (p<0.001). Trends in procedures were characterised by a narrowing gender gap, increasing mean patient age (p=0.014) and decreasing mean hospital stay (p<0.001). Linear regression models estimate that each hospital admission translates to 0.27 procedures, per 100,000 (95% CI 0.25 to 0.30, r 0.99, p<0.001; r, Pearson's correlation coefficient). Hospital admissions are increasing at 3.5 times the rate of surgical procedures (regression gradient 7.63 vs 2.18 per 100,000/year).

CONCLUSIONS

LBP represents a significant and increasing workload for hospitals in England. These trends demonstrate an increasing demand for specialists involved in the surgical and non-surgical management of this disease, and highlight the need for services capable of dealing with the increased comorbidity burden associated with an ageing patient group.

Focused image-guided parathyroidectomy in the current management of primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) in childhood and adolescence has been considered a different disease to that seen in adults, with predominantly familial aetiology mandating open exploration to exclude parathyroid hyperplasia in contrast to the adoption of focused image-guided parathyroidectomy (FP) in adults.

STUDY DESIGN

A retrospective cohort study in a tertiary referral hospital setting of all children and adolescents (<18 years) undergoing parathyroid surgery for PHPT. Data were obtained from a dedicated endocrine surgery database and hospital medical records.

RESULTS

Over the 35-year study period (1980-2014), there were 31 patients who underwent parathyroidectomy for PHPT. 3 patients were from known multiple endocrine neoplasia type 1 syndrome (MEN1) families, 3 had an isolated family history of PHPT and 25 were sporadic. In the sporadic group, 24 (96%) presented with symptomatic hypercalcaemia, affecting the gastrointestinal, musculoskeletal, genitourinary or neuropsychiatric systems. In the 25 patients with sporadic PHPT, nine (36%) had FP with a single adenoma removed with a 100% initial cure rate. Sixteen patients (64%) in the sporadic group had an open exploration: 14 had single gland disease while 2 patients required a second procedure to achieve a final cure rate of 100%. Of the three patients with MEN1, one was cured, one has persistent hyperparathyroidism after FP and the third has permanent hypoparathyroidism after open exploration.

CONCLUSIONS

The majority of children and adolescents with PHPT have symptomatic disease due to a single adenoma. They can therefore be managed in a similar fashion to their adult counterparts with preoperative localisation studies aiming to permit FP in a day case setting.