Focused parathyroidectomy without intraoperative parathyroid hormone measurement in primary hyperparathyroidism: Still a valid approach?

Intraoperative Parathyroid Hormone Monitoring Criteria in Primary Hyperparathyroidism: A Network Meta-Analysis of Diagnostic Test Accuracy

Importance

Intraoperative parathyroid hormone (IOPTH) monitoring is recommended by the American Association of Endocrine Surgeons for use during parathyroidectomy for patients with primary hyperparathyroidism (PHPT), but there is no clinician consensus regarding the IOPTH monitoring criteria that optimize diagnostic accuracy.

Objective

To evaluate and rank the diagnostic properties of IOPTH monitoring criteria used during surgery for patients with PHPT.

Data Sources

A bayesian diagnostic test accuracy network meta-analysis (DTA-NMA) was performed, in which peer-reviewed citations from January 1, 1990, to July 22, 2023, were searched for in MEDLINE, Embase, Web of Science, CENTRAL, and CINAHL.

Study Selection

All full-text study designs that evaluated any IOPTH monitoring criteria as a diagnostic test were included in this meta-analysis. Any studies evaluating adult patients diagnosed with PHPT undergoing parathyroidectomy were also included. The reference standard used in this study was normalization of calcium and/or parathyroid hormone levels within 1 year of surgery.

Data Extraction and Synthesis

This DTA-NMA was reported in accordance with the applicable Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Two reviewers evaluated all abstracts and full-text articles using a piloted extraction form. A third author resolved any conflicts. There are no published Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) resources for DTA-NMA. The following conventional monitoring criteria were included: Halle, Miami, Rome, Vienna, and PTH normalization, and the following modified criteria were included: Miami and PTH normalization, modified Miami, and modified Vienna. A bayesian hierarchical DTA-NMA model with corresponding 95% credible intervals (CrIs) was used to describe the pooled diagnostic characteristics of the evaluated IOPTH monitoring criteria.

Main Outcomes and Measures

Main outcomes included pooled diagnostic test properties, including sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio.

Results

A total of 72 studies, which included 19 072 patients, met the inclusion criteria. Sixty-nine studies (95.8%) investigated classic PHPT. In PHPT, the Miami criteria were investigated most often and had the best diagnostic properties (diagnostic odds ratio, 60.00 [95% CrI, 32.00-145.00]) when compared to other conventional criteria. Moreover, the modified Miami criteria, which measures a postexcision IOPTH level 15 minutes or more postexcision of all hyperfunctioning parathyroid tissue, were the overall best criteria (diagnostic odds ratio, 79.71 [95% CrI, 22.46-816.67]). There was a low risk of study bias and no publication bias.

Conclusions and Relevance

The results of this meta-analysis suggest that surgeons should use the modified Miami criteria when performing IOPTH-guided surgery for patients with PHPT because these criteria optimize intraoperative diagnostic accuracy by minimizing unnecessary neck exploration and revision surgery rates.

Diagnostic Performances of 18F-Fluorocholine PET/CT as First-Line Functional Imaging Method for Localization of Hyperfunctioning Parathyroid Tissue in Primary Hyperparathyroidism

RATIONALE AND OBJECTIVES

This study evaluated the diagnostic performance of 18F-fluorocholine (FCH) PET/CT as the first-line functional imaging method for preoperative localization of hyperfunctioning parathyroid glands (HPGs) in patients with primary hyperparathyroidism (PHPT).

MATERIALS AND METHODS

This retrospective single-center study included 80 consecutive patients with PHPT, referred for FCH PET/CT between January 2018 and July 2022, and who subsequently underwent surgery. The diagnostic performance of FCH PET/CT was compared to histological results for per-lesion analysis, and to postoperative resolution of biochemical PHPT for per-patient analysis.

RESULTS

18F-FCH-PET/CT revealed 95 positive foci in 77/80 patients and was negative in 3/80 patients. Postoperative resolution of HPT was obtained in 67/80 patients (84%). Per-lesion analysis showed 80 true positives, five true negatives, 11 false negatives, and eight false positives. Seven PET-positive foci could not be compared to histology. In a first per-lesion analysis, excluding these seven anomalies, sensitivity and positive predictive value (PPV) of FCH PET/CT were 88% (95% CI: 79-94) and 91% (95% CI: 87-94), respectively. In a second per-lesion analysis considering the seven anomalies as false positives (maximum bias analysis), PPV was 84% (95% CI: 80%-87%). By per-patient analysis, FCH PET/CT correctly identified and located all pathological glands in 56/80 (70%, 95% CI: 59-80) patients.

CONCLUSION

18F-Fluorocholine PET/CT appears to be an effective pre-surgical imaging method for localization of hyperfunctioning parathyroid tissue in patients with PHPT.

Advances in Endocrine Surgery

Recent changes in the landscape of endocrine surgery include a shift from total thyroidectomy for almost all patients with papillary thyroid cancer to the incorporation of thyroid lobectomy for well-selected patients with low-risk disease; minimally invasive parathyroidectomy with, and potentially without, intraoperative parathyroid hormone monitoring for patients with well-localized primary hyperparathyroidism; improvement in the management of parathyroid cancer with the incorporation of immune checkpoint blockade and/or targeted therapies; and the incorporation of minimally invasive techniques in the management of patients with benign tumors and selected secondary malignancies of the adrenal gland.

Contribution of intraoperative parathyroid hormone monitoring to the surgical success in minimal invasive parathyroidectomy

Background

The contribution of intraoperative parathyroid hormone monitoring to minimally invasive parathyroidectomy remains controversial. We aimed to evaluate whether intraoperative parathyroid hormone monitoring monitoring could contribute to minimally invasive parathyroidectomy in these patients.

Methods

The data of the patients whose preoperative ultrasonography and technetium-99 m sestamibi scintigraphy imagings were positive and concordant for one gland and who underwent minimally invasive parathyroidectomy between 2003 and 2018 in our clinic, were evaluated retrospectively. Blood samples were collected at pre-excisional period, and at post-excisional 10 and 20 min; the intaoperative parathyroid hormone was measured, and the surgery was terminated without waiting for the result. Patients were divided into 2 groups according to the postoperative results, as those with normocalcemia (Group 1) and those with persistence (Group 2).

Results

There were 195 patients in Group 1 and 14 patients in Group 2. The cure rate at the first surgery was 93.3%. Cure was achieved after the second operation in all patients in Group 2. Recurrent disease developed in 1 patient in group 1 and the overall cure rate was 99.5%. If intraoperative parathyroid hormone had been evaluated, cure could have been achieved at the first surgery with additional exploration, in 10 (71.4%) of 14 patients according to the insufficient decrease in parathyroid hormone value at the 10 min in Group 2, and in 9 (64.3%) of 14 patients according to the parathyroid hormone value at 20 min. However, due to insufficient decrease (false negative) in the parathyroid hormone value at the 10 and 20 min the rate of false negatives and unnecessary exploration would be 9.5% and 2.5%, respectively. With additional exploration, the cure rate in the first surgery could be increased by 4.3%–97.6% according to the 20 min intraoperative parathyroid hormone value.

Conclusion

The cure rate in minimally invasive parathyroidectomy can be increased by minimizing unnecessary conversion to bilateral neck exploration, by evaluating intraoperative parathyroid hormone at 10 min in patients with positive and concordant scans, and intraoperative parathyroid hormone at 20 min in patients with inadequate decrease at 10 min intraoperative parathyroid hormone.

How and when is multiglandular disease diagnosed in sporadic primary hyperparathyroidism?

BACKGROUND

In total, ∼15% of patients with sporadic primary hyperparathyroidism have multiglandular disease, which may be suspected preoperatively but can only be confirmed intra or postoperatively. The study aim is to determine how and when patients are diagnosed with multiglandular disease and to what extent different modalities contribute.

METHODS

Consecutive cases of sporadic primary hyperparathyroidism (2013-2019) undergoing initial exploration were reviewed from a single-institution prospective database. Preoperative single-photon emission tomography/computed tomography and neck ultrasound were routinely performed to help direct either bilateral or unilateral exploration guided by intraoperative parathyroid hormone monitoring using the dual criteria. Multiglandular disease was defined as either resection of >1 enlarged parathyroid or hypercalcemia at ≥6 months after single gland resection.

RESULTS

Of 1,890 patients with sporadic primary hyperparathyroidism, multiglandular disease was identified in 254 (13.4%); 244 (96.1%) were diagnosed intraoperatively and 10 (3.9%) postoperatively. In these multiglandular disease patients, single gland disease was suggested on single-photon emission tomography/computed tomography in 54.0%, ultrasound in 49.2%, and both were concordant for single gland disease in 29.4%. Intraoperative multiglandular disease diagnosis was prompted by an inadequate intraoperative parathyroid hormone monitoring drop in 38.5%, by surgeon interpretation of imaging in 38.1%, by observing ipsilateral gland enlargement in 11.0%, by finding an initial gland <200 mg in 10.3%, and 2.0% had unexpected multiglandular disease during thyroidectomy. Multiglandular disease was diagnosed by postoperative hypercalcemia in 10 of 254 patients (4.9%).

CONCLUSION

To avoid failure at parathyroidectomy for primary hyperparathyroidism, expert surgeons use multiple approaches to diagnose and manage multiglandular disease. Preoperative localization studies alone are insufficient, missing multiglandular disease in at least 30% of cases. All examined adjuncts are informative, including intraoperative parathyroid hormone monitoring, imaging, and intraoperative visual cues.