Correlation of Preoperative Imaging Findings and Parathyroidectomy Outcomes Support NICE 2019 Guidance

Overview of Thyroid and Parathyroid Disease: The Otolaryngology Perspective

The management of thyroid and parathyroid pathology varies widely, with unifying goals of symptomatic control and mitigating patient morbidity. In general, surgery is indicated when addressing malignancy or when medical management is insufficient. Over the last few decades, treatment paradigms for patients with head and neck endocrine disease have shifted significantly as our understanding of disease processes has expanded and with the advent of numerous relevant technologies. Here we provide a general overview of thyroid and parathyroid disease that may be managed by the otolaryngologist, with attention to emerging strategies in diagnosis and treatment.

[Special features of the diagnostics and treatment of hereditary primary hyperparathyroidism]

Between 2% and 10% of patients with primary hyperparathyroidism (pHPT) are diagnosed with hereditary forms of primary hyperparathyroidism (hpHPT). They are more prevalent in younger patients before the age of 40 years, in patients with persistence or recurrence of pHPT and pHPT patients with multi-glandular disease (MGD). The various forms of hpHPT diseases can be classified into four syndromes, i.e., hpHPT associated with diseases of other organ systems, and four diseases that are confined to the parathyroid glands. Approximately 40% of patients with hpHPT suffer from multiple endocrine neoplasia type 1 (MEN-1) or show germline mutations of the MEN‑1 gene. Currently, germline mutations that lead to a specific diagnosis in patients with hpHPT have currently been described in 13 different genes, which enables a clear diagnosis of the disease; however, a clear genotype-phenotype correlation does not exist, even though the complete loss of a coded protein (e.g. due to frame-shift mutations in the calcium sensing receptor, CASR) often leads to more severe clinical consequences than merely a reduced function of the protein (e.g. due to point mutation). As the various hpHPT diseases require different treatment approaches, which do not correspond to that of sporadic pHPT, a clear definition of the specific form of hpHPT must always be strived for. Therefore, before surgery of a pHPT with clinical, imaging or biochemical suspicion of hpHPT, genetic proof or exclusion of hpHPT is necessary. The differentiated treatment approach for hpHTP can only be defined by taking the clinical and diagnostic results of all the abovenamed findings into account.

Evaluation of Surgeon-Performed Ultrasonography With or Without Contrast Enhancement vs Scintigraphy in Patients With Primary Hyperparathyroidism

Importance

Scintigraphy and ultrasonography are common imaging modalities for the preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism. When comparing the 2 modalities, the benefits of ultrasonography in terms of convenience, patient comfort, duration, cost, and lack of radiation should be taken into account.

Objective

To investigate whether surgeon-performed ultrasonography, with or without contrast-enhanced ultrasonography (CEUS), is noninferior to scintigraphy for localizing pathological parathyroid glands in patients with primary hyperparathyroidism.

Design, Setting, and Participants

Prospective, paired, noninferiority cohort study performed at a high-volume tertiary referral center for parathyroidectomy with blinded examiners and a 6-month follow-up. Participants were adults (age ≥18 years) referred for parathyroidectomy due to primary hyperparathyroidism. Of 207 eligible patients, 35 were excluded, leaving 172 enrolled in the study. Inclusion lasted from September 2019 until February 2021. Follow-up ended in December 2021.

Exposures

99mTechnetium-pertechnetate/99mtechnetium-sestamibi subtraction scintigraphy with 99mtechnetium-sestamibi single-photon emission computed tomography/computed tomography, followed by surgeon-performed ultrasonography and CEUS.

Main Outcomes and Measures

The sensitivity of each imaging modality in localizing pathological parathyroid glands, calculated on a per-quadrant and a per-patient basis, respectively. The a priori noninferiority margin was a lower 95% confidence limit for the difference in sensitivity not falling below -10%.

Results

Out of 172 participants, 139 (80.8%) were women, the median (range) age was 65 (24-87) years, and the median (IQR) follow-up was 200.5 (181-280.25) days. Quadrant sensitivity (95% CI) was 70.9% (63.2%-78.5%) for ultrasonography, 68.4% (60.4%-76.5%) for ultrasonography plus CEUS, and 67.0% (60.0%-74.0%) for scintigraphy. The sensitivity difference (95% CI) compared with scintigraphy was 3.9% (-4.1% to 11.8%) for ultrasonography and 1.5% (-6.4% to 9.3%) for ultrasonography plus CEUS, establishing noninferiority for both modalities. Per-patient sensitivity was 81.4% (74.8%-86.9%) for ultrasonography and 79.1% (72.2%-84.9%) for both scintigraphy and ultrasonography plus CEUS. The sensitivity difference compared with scintigraphy was 2.3% (-6.8% to 11.4%) for ultrasonography and 0.0% (-9.1% to 9.1%) for ultrasonography plus CEUS, establishing noninferiority for both modalities.

Conclusions and Relevance

In this cohort study, conventional ultrasonography by an experienced parathyroid surgeon-sonographer was noninferior to scintigraphy and may constitute a valid first-line imaging modality in patients with primary hyperparathyroidism, even without the addition of CEUS. Further imaging should be reserved for cases that are equivocal or nonlocalizing on ultrasonography.

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.

Long-term outcome of surgical techniques for sporadic primary hyperparathyroidism in a tertiary referral center in Belgium

PURPOSE

Surgery remains the only permanent treatment option for primary hyperparathyroidism (pHPT). To date, the number of long-term outcome studies of parathyroidectomy is limited. This study aims to compare different surgical approaches and evaluate the importance of preoperative localization imaging in the treatment of pHPT.

METHODS

All 200 consecutive patients with a parathyroidectomy for sporadic pHPT without planned concomitant surgery between 09/2009 and 04/2021 in a Belgian tertiary referral hospital were enrolled. All patients underwent at least two preoperative localization imaging studies (neck ultrasound, CT, SPECT, and/or Sestamibi scintigraphy) of the parathyroid glands. The main outcomes were the (long-term) cured proportion and postoperative morbidity (hypocalcemia, recurrent laryngeal nerve palsy, return to theater for bleeding, and wound morbidity).

RESULTS

Most patients were referred with concordant positive imaging (82%, n = 164). Only nine patients (4.5%) had double negative imaging, not revealing a possible adenoma. The remaining 27 (13.5%) were referred with discordant imaging. Parathyroidectomy was performed via traditional cervicotomy (30%), mini-open approach (39.5%), or endoscopic approach (30.5%). Morbidity was low with no persistent hypocalcemia, one return to theater for bleeding, and no 30-day mortality. In the concordant imaging population, 13 patients (8%) had multiglandular disease. Overall, 97.5% was considered cured. Long-term recurrence was 12% with a minimal follow-up of 5 years.

CONCLUSION

This consecutive, single-surgeon, single-center cohort with extensive data collection and long-term follow-up confirms the safety and excellent cured proportions of minimally invasive parathyroidectomy. Disease recurrence becomes more important long after surgery.