Accuracy of 4-Dimensional Computed Tomography for Localization in Primary Hyperparathyroidism

4DCT in Discordant Parathyroid Adenoma Scans: Case Series and Meta-Analysis

OBJECTIVE

To evaluate the accuracy of four-dimensional computerized-tomography (4DCT) for localizing parathyroid adenomas (PTAs) in cases with discordant or non-localizing ultrasonography (US) and Technetium-99 sestamibi (MIBI) scans.

DATA SOURCES

Retrospective case series and systematic review.

REVIEW METHODS

A case series and meta-analysis of patients diagnosed with primary hyperparathyroidism and discordant US and MIBI scans who underwent 4DCT prior to surgery. A comprehensive search for all relevant publications in the English literature between December 2006 and March 2022 was conducted for the meta-analysis. Patients undergoing parathyroidectomy between January 2015 and December 2021 were identified from the institutional electronic database for the case series. All studies were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 4DCT adenoma localization capabilities.

RESULTS

Thirteen retrospective studies that included 379 patients and one case series that included 37 patients were identified and analyzed. A per-patient analysis revealed sensitivity for lateralization to the correct side (n = 181) ranging from 80% to 100% with a fixed effects model of 89% (95%confidence interval [CI]: 82%-93%) and a PPV for lateralization ranging from 63%-95% with a random effects model of 87% (95% CI: 77%-95%). Sensitivity of localization to the correct quadrant (n = 172) ranged from 53% to 100% with a random effects model of 90.4% (95% CI: 76%-99%), and the PPV for localization ranged from 52% to 100% with a random effects model of 82% (95% CI: 73%-89%).

CONCLUSION

4DCT enhances imaging capabilities of localizing PTAs in cases of discordant or non-localizing US and MIBI scans.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2198-2205, 2024.

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.

Association Between Size of Dominant Candidate Lesion on Four-Dimensional CT and Four-Gland Hyperplasia among Patients with Primary Hyperparathyroidism

BACKGROUND

Four-dimensional (4D) CT localization allows minimally invasive parathyroidectomy as treatment for primary hyperparathyroidism (PHPT), but false positive localization is frequent. We sought to characterize the ability of 4D CT to predict four-gland hyperplasia (HP) based on the size of candidate lesions.

STUDY DESIGN

We retrospectively analyzed patients with PHPT who underwent 4D CT imaging and parathyroidectomy between 2014 and 2020 from a prospectively collected institutional database. The cohort was stratified into two groups, HP vs single adenoma (SA) and double adenoma (DA), based on operative findings and pathology. Logistic regression models assessed the association between the greatest diameter of the dominant candidate lesion on 4D CT and the outcomes of four-gland hyperplasia vs SA and DA.

RESULTS

Among a cohort of 240 patients, 41 were found to have HP, and 199 had adenomas (SA = 155, DA = 44). Patients with HP were less likely to have a preoperative calcium level greater than 1 mg/dL above the upper limit of normal compared with patients with adenomas (63% vs 81%, p = 0.02) and more likely to report symptoms (61% vs 43%, p = 0.04). After adjusting for BMI, we found an estimated 13% reduction in odds of HP for every 1-mm increase in the greatest diameter of dominant candidate lesions identified on 4D CT scan (odds ratio 0.87, 95% CI 0.78 to 0.96, p = 0.009).

CONCLUSIONS

A smaller size of the dominant lesion on 4D CT scan is associated with an increased risk of HP in PHPT. Use of 4D CT imaging localization may provide evidence for differentiating HP from adenomas.

Advanced Computed Tomographic Localization Techniques for Primary Hyperparathyroidism: A Systematic Review and Meta-analysis

Importance

Emerging computed tomographic (CT) imaging techniques for the localization of primary hyperparathyroidism (PHPT) may be superior to the current imaging standard, thus necessitating a critical review and pooling of available evidence.

Objective

Primary hyperparathyroidism requires accurate imaging to guide definitive surgical management. Advanced techniques including 4-dimensional computed tomographic (4D-CT) scan have been investigated over the past decade. We sought to evaluate the efficacy of these emerging imaging techniques through pooled analysis of the existing evidence.

Data Sources

PubMed, Embase, and Web of Science databases were queried for original English articles without any restrictions on date.

Study Selection

We included comparative observational studies but excluded animal studies, case reports, and case series. Overall, 353 abstracts were screened independently by 2 investigators along with a third reviewer to resolve conflicts. A total of 26 full-text articles were included in this review.

Data Extraction and Synthesis

This review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data was independently extracted by 2 investigators and subsequently pooled into a meta-analysis using a random-effects model.

Main Outcomes and Measures

Measures of imaging diagnostic performance such as sensitivity, specificity, positive predictive value, and negative predictive value were the primary outcomes of interest.

Results

Overall, of 34 articles screened, 26 met criteria for qualitative synthesis, and 23 of these were appropriate for meta-analysis. Of the 26 studies included, there were 5845 patients, of which 4176 were women (79.2%). The average of mean ages reported in 23 studies was 60.9 years. Meta-analysis in all patients with PHPT revealed pooled sensitivity that was greater with 4D-CT (81%; 95% CI, 77%-84%; I2 = 88%) compared with the current first-line modality of sestamibi-single-photon emission CT (SPECT/CT) (65%; 95% CI, 59%-70%; I2 = 93%). For patients with recurrent PHPT requiring reoperation, 4D-CT pooled sensitivity was 81% (95% CI, 64%-98%; I2 = 93%) in contrast to 53% (95% CI, 35%-71%; I2 = 81%) for sestamibi-SPECT/CT. The overall quality of the 26 studies was moderate with a median (range) Methodological Index for Nonrandomized Studies score for all included studies of 15.5 (13-19).

Conclusions and Relevance

The findings of this systematic review and with meta-analyses of numerous studies from the past decade suggest that the 4D-CT can be more sensitive and specific than sestamibi-SPECT/CT in localizing PHPT. More research is needed to determine the clinical significance of this improvement in localization.

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.

Surgical management of MILD hyperparathyroidism

INTRODUCTION

There is no consensus for management of Mild primary hyperparathyroidism (MILD-pHP). Specific management has been suggested by some authors. We have compared the surgical management of the patients with MILD-pHP to those with Classic primary hyperparathyroidism (C-pHP) treated by surgery according to The Fourth International Workshop on pHP.

MATERIALS AND METHODS

Data of 173 patients who underwent a parathyroidectomy were reviewed and retrospectively analysed. Management of 32 patients with MILD-pHPT (18.5%) patients were compared to that of 141 (81.5%) patients with C-pHPT.

RESULTS

MILD-pHP group was more often discovered after non-fractured osteoporosis (21.9% vs 7.1%, p = 0.02) and surgery for chondrocalcinosis was more often carried out (6.3% vs 0%, p = 0.03) in the MILD-pHP group. A Mini-Invasive Parathyroidectomy (MIP) was carried out in 81.3% of cases, and 87.5% of patients had a single adenoma. The rate of multiglandular pathology was not different. Same day discharge was significantly higher in MILD-pHP group (37.5% vs 17.7%, p = 0.01). Success was obtained in 87.5% in the MILD-pHP group, there was no significant difference with the C-pHP group (92.9%, p = 0.48). There was no significant difference in the imaging performances. Imaging discordance was observed in 18.8% of cases in MILD-pHP and 33.6% in C-pHP (p = 0.38) without correlation with surgical failure.

CONCLUSION

This study suggests that, by selecting patients on the basis of concordant imaging and international recommendations, there is no difference in outcome between MILD-pHP and C-pHP treated surgically.

Diagnostic Role of Four-Dimensional Computed Tomography for Preoperative Parathyroid Localization in Patients with Primary Hyperparathyroidism: A Systematic Review and Meta-Analysis

We sought to systematically evaluate diagnostic performance of four-dimensional computed tomography (4D-CT) in the localization of hyperfunctioning parathyroid glands (HPGs) in patients with primary hyperparathyroidism (pHPT). We calculated the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratios (DOR) of 4D-CT on a per-lesion level, as well as pooled sensitivity and positive predictive value (PPV) on a per-patient level with 95% confidence intervals (CIs). Additionally, we plotted summary receiver operating characteristic (SROC) curves and evaluated the areas under the curves (AUC). A total of 16 studies were included in the analysis. Their pooled sensitivity, specificity, PLR, NLR, and DOR of 4D-CT on per-lesion level were 75% (95%CI: 66–82%), 85% (95%CI: 50–97%), 4.9 (95%CI: 1.1–21.3), 0.30 (95%CI: 0.19–0.45), and 17 (95%CI: 3–100), respectively, with an AUC of 81% (95%CI: 77–84%). We also observed heterogeneity in sensitivity (I² = 79%) and specificity (I² = 94.7%), and obtained a pooled sensitivity of 81% (95%CI: 70–90%) with heterogeneity of 81.9% (p < 0.001) and PPV of 91% (95%CI: 82–98%) with heterogeneity of 80.8% (p < 0.001), based on a per-patient level. Overall, 4D-CT showed moderate sensitivity and specificity for preoperative localization of HPG(s) in patients with pHPT. The diagnostic performance may improve with 4D-CT’s promotion to first-line use on a lesion-based level, further research is needed to confirm the results.