Ultrasonography for preoperative localization of enlarged parathyroid glands in primary hyperparathyroidism: comparison with (99m)technetium sestamibi scintigraphy

Primary hyperparathyroidism: from guidelines to outpatient clinic

Primary hyperparathyroidism (PHPT) is a common endocrine disease characterized by hypercalcemia due to inappropriately high parathyroid hormone secretion. While in the typical, symptomatic form of the disease diagnosis is set easily and standard management is surgical removal of the hyperfunctioning parathyroid (HP), this may not be the case in more subtle forms of PHPT, such as the asymptomatic and the normocalcemic PHPT. Localization of the HP could also be challenging, especially in small-sized adenomas, ectopic lesions or multiglandular disease. An experienced surgical team is essential to achieve curative parathyroidectomy. In this article, we used illustrative clinical vignettes to dissect the approach to the patient with PHPT, from the diagnosis establishment to the suggested investigation to identify classical and non-classical PHPT features and the methodology to locate the abnormal tissue. Accordingly, we elaborated on appropriate management, both surgical and conservative.

PET-TC [18F]F-choline and intraoperative PTH in the surgical treatment of the primary hyperparathyroidism without preoperative location

BACKGROUND AND OBJECTIVES

To assess the feasibility of performing selective parathyroidectomy without intraoperative parathyroid hormone (PTHio) determination when first-line preoperative localization tests (ultrasonography and [99mTc]Tc-MIBI) are negative and/or discordant, and second-line [18F]F-Colina PET-CT, is positive.

MATERIALS AND METHODS

Retrospective cohort study, including patients with negative or discordant ultrasound and MIBI scans and positive [18F]F-Colina PET-CT, who underwent selective parathyroidectomy between 2019 and 2022. Groups were compared based on PTHio determination. Study variables were: gender, mean age, biochemical cure assessed by PTH value (pg/mL) and corrected calcium by albumin (mg/dL) at 6 months post-surgery follow-up, and histopathological analysis.

RESULTS

The final sample included 42 patients. At 6 months post-surgery, in the PTHio group (20 patients), PTH values were 64.50 pg/mL and calcium 9.30 pg/mL, with 19 adenomas and 1 hyperplasia found. In the non-PTHio group (22 patients), PTH values were 61 pg/mL and calcium 9.37 pg/mL, with 22 adenomas found. No statistically significant differences were found between both groups.

CONCLUSIONS

Based on the results obtained in our patient cohort, selective parathyroidectomy could be considered with negative or discordant first-line tests and positive [18F]F-Colina PET-CT, without intraoperative PTH determination.

Localization of Ectopic Hyperparathyroidism: Ultrasound Versus 99mTc-sestamibi, 4-Dimensional Computed Tomography, and 11C-choline Positron Emission Tomography/Computed Tomography

OBJECTIVE

To investigate the usefulness of ultrasound (US) for the localization of ectopic hyperparathyroidism and compare it with 99mTc-sestamibi (99mTc-MIBI), 4-dimensional computed tomography (4D-CT), and 11C-choline positron emission tomography/ computed tomography (PET/CT).

METHODS

Of the 527 patients with surgically confirmed primary hyperparathyroidism, 79 patients with ectopic hyperparathyroidism were enrolled. The diagnostic performance of US, 99mTc-MIBI, US + MIBI, 4D-CT, and 11C-choline PET/CT was calculated, and the factors affecting the sensitivity of US and 99mTc-MIBI were analyzed.

RESULTS

Eighty-three ectopic parathyroid lesions were found in 79 patients. The sensitivity was 75.9%, 81.7%, 95.1%, 83.3%, and 100% for US, 99mTc-MIBI, US + MIBI, 4D-CT, and 11C-choline PET/CT, respectively. The difference in sensitivity among these different modalities did not achieve statistical significance (P > .05). The US sensitivity was significantly higher for ectopic lesions in the neck region than for those in the anterior mediastinum/chest wall (85.9% vs. 42.1%, P < .001). The 99mTc-MIBI and 4D-CT sensitivity was not significantly different between these two groups (84.1% vs. 94.6%, P = .193 and 81.3% vs. 85.7%, P = 1). The 11C-choline PET/CT sensitivity was 100% in both groups.

CONCLUSIONS

US is a valuable tool for the localization of ectopic hyperparathyroidism, especially for ectopic lesions in the neck region.

Brown tumor due to primary hyperparathyroidism in a familial case: a case report

BACKGROUND

Primary hyperparathyroidism (PHPT) is an uncommon disorder characterised by hypercalcemia with an increased parathyroid hormone level. We reported a PHPT familial case with two subjects, a father and a daughter, and both of them had suffered from the brown tumor.

CASE PRESENTATION

The proband, a 43-year-old patient, developed parathyroid adenomas at the age of 15; a histologically confirmed right parathyroid adenoma was removed by parathyroidectomy; and after six months follow-up, the serum calcium level was normalised. At the age of thirty-three, a CT scan of his head and neck revealed a mass in the right maxilla, as well as PHPT (i.e., left inferior parathyroid adenoma). Then, he underwent a biopsy of an exophytic lesion in the right maxilla and was diagnosed by pathology as a brown tumor, with the serum calcium and PTH levels at 2.78 mmol/L and 221 pg/mL, respectively. Subsequently, the patient took a left inferior parathyroid microwave ablation with ultrasound guidance. After three months of follow-up, the serum calcium and PTH levels returned to normal, and the brown tumor was resolved. After three years, it mineralised as revealed in a CT scan. By the time he was 43 years old, during the 28-year follow-up period, the serum calcium and PTH levels were still within the normal range, and there was no discomfort reported. He has consistently taken calcium supplements throughout the 28 years. Since the initial diagnosis, his blood indicators of kidney function have been normal, and ultrasound showed renal calculus in the right kidney and a normal left kidney. The proband's daughter, a 15-year-old girl, experienced left upper extremity pain for ten months. CT scan revealed a mass in the distal left radius, and a giant cell tumor was suspected. A surgical internal fixation was performed, and the pathology showed a brown tumor. Laboratory tests revealed a serum parathyroid hormone (PTH) level of 1554pg/mL, calcium level of 3.14 mmol/L, phosphorus level of 0.72 mmol/L, and alkaline phosphatase level of 1892 U/L. Given the osteitic changes and elevated levels of calcium and PTH, ultrasonography was performed, after which a mass was detected measuring 19 × 9 × 7 mm mixed with solid components and cystic fluid in the right thyroid gland. The results of 99mTc-MIBI scintigraphy confirmed the abnormal accumulation of 99mTc-MIBI in the right thyroid gland but not seen in the bilateral parathyroid glands. The patient underwent thyroidectomy, and the postoperative pathology report indicated an intra-thyroid ectopic parathyroid adenoma. The serum calcium and PTH levels became normal at 4 h after surgery. One to three months after operation, the serum calcium level was low, while the serum PTH level was high. Then, the patient was advised to take calcium supplements. Until the sixth month after the operation, the serum calcium level and serum PTH level returned to normal, and the bone pain was relieved. The patient's blood tests for kidney function remained normal. There was no evidence of bilateral kidney disease (such as nephrolithiasis or nephrocalcinosis) detected by ultrasound scan. There were several similarities in the state of illness between these two subjects. Both the father and the daughter developed parathyroid adenomas at the age of 15, and there was no lesion in other endocrine glands. And genetic testing revealed mutations in the CDC73 genes in both father and daughter. On the other hand, there were also a few differences. The father's first signs of brown tumor were in the right maxilla, while the daughter's appeared in the distal left radius. The father presented pathological changes in the left and right parathyroid glands, whereas the daughter presented with an ectopic parathyroid adenoma in the right thyroid gland.

CONCLUSION

We report a familial case in which father and daughter were diagnosed to have brown tumors due to parathyroid adenoma and ectopic parathyroid adenoma, and genetic testing revealed CDC73 gene mutations in both. Therefore, in the diagnostic and differential process of young patients having bone disease, clinicians should not only focus on the clinical manifestations of the skeleton, but also implement a comprehensive analysis of systemic symptoms, considering the possibility that the patient has familial PHPT.

Parathyroid carcinoma: Three case reports

BACKGROUND

Parathyroid carcinoma (PC) is a rare, slow-growing malignant tumor and a rare cause of primary hyperfunctioning of the parathyroid, with a highly variable clinical course, depending on the aggressiveness of the individual tumor and the degree of hypercalcemia.

CASE SUMMARY

The aim of this report is to summarize the diagnosis and treatment of three cases of PC and to review and conclude aspects regarding the three collected cases with reference to other relevant cases to explore the value of ultrasound in the diagnosis of PC. All three patients had hypercalcemia, consisting of a high serum calcium level and a high level of parathyroid hormone that was > 2-fold (even > 30-fold) of the normal upper limit. The ultrasonographic findings of the parathyroid gland showed that the glands were all > 30 mm, and the internal echo was uneven. All patients underwent surgery. PC in three cases was confirmed by routine histopathology and immunohistochemistry.

CONCLUSION

As clinical signs and laboratory results are nonspecific, it is difficult to diagnose PC preoperatively, so imaging examinations are often needed.

Robot-Assisted Parathyroidectomy Using Indocyanine Green (ICG) Fluorescence in Primary Hyperparathyroidism

Background and Objectives: Surgical treatment for primary hyperparathyroidism (PHPT) has evolved from bilateral exploration through a long transcervical incision to focused parathyroidectomy with a minimal incision above the pathologic gland. Recently, endoscopic or robot-assisted parathyroid surgery without direct neck incision has been introduced. The aim of this study was to investigate the effectiveness of indocyanine green (ICG) fluorescence as a new method for the visual identification of abnormal hyperfunctioning parathyroid glands in robot-assisted parathyroidectomy using FireflyTM technology. We also aimed to conduct a comparative analysis between robot-assisted parathyroidectomy and conventional focused parathyroidectomy in order to identify clinical differences between the two surgical approaches. Materials and Methods: A total of 37 patients with PHPT underwent parathyroidectomy at a single university hospital between September 2018 and December 2022. Thirty-one patients underwent open focused parathyroidectomy (open group), and six patients underwent robot-assisted parathyroidectomy (robot group). Pre-operative localization via parathyroid SPECT-CT and an intraoperative parathyroid hormone (IOPTH) assay were used to successfully remove the pathologic parathyroid in both groups. ICG was administered only in the robot group. Results: Pathologic parathyroid showed a persistent fluorescence pattern under near-infrared vision. After the removal of the fluorescent parathyroid gland, IOPTH was normalized in all six patients in the robot group. However, the open group showed shorter hospital stays (1.8 ± 1.2 vs. 3.0 ± 0.0 days, p < 0.001) and shorter operation times (91.1 ± 69.1 vs. 152.5 ± 23.6 min, p = 0.001) than the robot group. After 6 months of surgery, PTH, calcium, and ionized calcium levels were all normalized without significant differences between the groups. Conclusions: Robot-assisted parathyroidectomy using ICG is helpful for the visual identification of the pathologic parathyroid gland. The advantage of robot parathyroidectomy is a better cosmetic outcome. However, it still does not show better clinical outcomes than conventional open focused parathyroidectomy.

Comparison of Neck Ultrasonography, Dual Phase 99mTc-Sestamibi with early SPECT-CT & 18F-Fluorocholine PET-CT as First Line Imaging in Patients with Primary Hyperparathyroidism

Introduction

Successful surgical treatment for primary hyperparathyroidism requires accurate localization of abnormal parathyroid tissue in terms of location and number. Imaging is important for localizing the parathyroid adenoma, and there has been significant interest in 18F-fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) for this purpose.

Aim

This study attempted to ascertain the utility of 18F-FCH PET/CT as a first-line investigation in preoperative localization of abnormal parathyroid tissue in primary hyperparathyroidism, in comparison with 99mTc-sestamibi dual-phase scintigraphy with early single-photon emission computed tomography (SPECT)/CT and neck ultrasonography.

Materials and Methods

Fifty-five patients with biochemical features of primary hyperparathyroidism were enrolled in this study. They underwent neck ultrasonography, 99mTc-sestamibi dual-phase scintigraphy with early SPECT/CT, and 18F-FCH PET/CT for localization of parathyroid lesions. Thirty-three patients underwent surgical resection of the detected lesions. For two patients, clinical and biochemical follow-up was used as a gold standard.

Results

A total of 40 lesions were resected in the 33 patients who underwent surgery. A further two lesions were localized in two patients with clinical and biochemical follow-up as the gold standard. Of these 42 lesions, 41 were detected in preoperative imaging and 1 lesion was noted intraoperatively and resected. 41/42 lesions were detected by 18F-FCH PET/CT (detection rate: 97.6%), 33/42 by 99mTc-sestamibi dual-phase scintigraphy with early SPECT/CT (detection rate: 78.5%), and 30/42 by neck ultrasonography (detection rate: 71.4%).

Conclusion

Detection rates on 18F-FCH PET/CT were superior to both 99mTc-sestamibi dual-phase scintigraphy with early SPECT/CT and neck ultrasonography in preoperative localization of parathyroid lesions in patients with primary hyperparathyroidism.

Minimally Invasive Parathyroidectomy as the Surgical Management of Single Parathyroid Adenomas: A Tertiary Care Experience

The aim of our study is to assess the feasibility, safety and adequacy of focused parathyroidectomy for single parathyroid adenoma accurately localized preoperatively by ultrasound neck and Tc99m sestamibi scan. The study was conducted in the department of Otorhinolaryngology of SMS Medical College and Hospital, Jaipur on 116 patients of primary hyperparathyroidism who underwent minimally invasive parathyroidectomy (MIP) for single gland adenoma localized by USG neck and tc99m sestamibi scans. S. Calcium and S. PTH followed up on day 1, 6th week and 6th month. Outcomes were determined on the basis of cure rate, duration of hospitalization, complication rates and disease persistence/recurrence rate. 82 (70.68%) females and 34 (29.31%) males belonging to the age group of 21-67 years (43.02 ± 14) formed the basis of our study. Skeletal (73.27%) and renal (62.93%) were the most common presentations. Accuracy of USG and sestamibi accurately was 93.10% and 96.55% respectively with combined accuracy of 100%. Preoperative serum calcium levels of 10.7-16.03 mg/dl (13.09 ± 2.11) and serum PTH 127-2196 pg/ml (846.57 ± 776.55) were observed. Cure rate of MIP was 99.13%. No permanent complications seen. MIP can be used as the surgical procedure of choice for PHPT caused by single gland adenoma aided by USG and sestamibi scan. The cure rates are equivalent to the bilateral neck exploration (> 95%) with minimal morbidity and complications. Hence, it is a more feasible, safe and effective treatment option.

The magic mirror: a novel intraoperative monitoring method for parathyroid glands

The accurate detection of parathyroid glands (PGs) during surgery is of great significance in thyroidectomy and parathyroidectomy, which protects the function of normal PGs to prevent postoperative hypoparathyroidism and the thorough removal of parathyroid lesions. Existing conventional imaging techniques have certain limitations in the real-time exploration of PGs. In recent years, a new, real-time, and non-invasive imaging system known as the near-infrared autofluorescence (NIRAF) imaging system has been developed to detect PGs. Several studies have confirmed that this system has a high parathyroid recognition rate and can reduce the occurrence of transient hypoparathyroidism after surgery. The NIRAF imaging system, like a magic mirror, can monitor the PGs during surgery in real time, thus providing great support for surgeries. In addition, the NIRAF imaging system can evaluate the blood supply of PGs by utilizing indocyanine green (ICG) to guide surgical strategies. The NIRAF imaging system and ICG complement each other to protect normal parathyroid function and reduce postoperative complications. This article reviews the effectiveness of the NIRAF imaging system in thyroidectomies and parathyroidectomies and briefly discusses some existing problems and prospects for the future.

The relationship between 18F-FCH uptake intensity and cell content in parathyroid lesions

PURPOSE

To investigate the relationship between cell content and histopathological features of parathyroid lesions and 18F-FCH uptake intensity on PET/CT images.

METHODS

Patients with primary hyperparathyroidism (age > 18) who were referred to 18F-FCH PET/CT were involved. All patients underwent parathyroidectomy. Correlation of SUVmax with following factors were statistically analysed: serum PTH, Ca, P levels and histopathological parameters, total absolute amounts of chief cell, oxyphyllic cell and clear cell components calculated by the multiplication of the volume of the parathyroid lesion and the percentage of each type of cell content (called as Absolute_chief, Absolute_oxyphyllic and Absolute_clear reflecting the total amount of each cell group).

RESULTS

A total of 34 samples from 34 patients (6M, 28F, mean age: 53.32 ± 15.15, min: 14, max: 84) who had a positive 18F-FCH PET/CT localizing at least one parathyroid lesion were involved. In the whole study group, SUVmax was found to be correlated with the greatest diameter and volume of the lesion and Absolute_chief (p = 0.004, p = 0.002 and p = 0.035, respectively). In the subgroup analysis of 28 samples with longest diameter > 1 cm, the correlation between SUVmax and Absolute_chief remained significant (p = 0.036) and correlation between SUVmax and volume and longest diameter became stronger (p = 0.011 and p > 0.001, respectively). No correlation was found between SUVmax and Absolute_oxyphyllic or Absolute_clear.

CONCLUSIONS

There might be a relationship between 18F-FCH uptake intensity and chief cell content in patients with parathyroid adenoma. Further studies with larger patient groups would be beneficial to support the data.

[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.

The use of computed tomography as a first-line imaging modality in patients with primary hyperparathyroidism

BACKGROUND

The success of minimally invasive parathyroidectomy (MIP) relies on accurate localization of the abnormal parathyroid glands. Concordant findings on ultrasound (US) and ^99mTc-scintigraphy (sestamibi) are currently considered the 'gold standard'. Computed tomography (CT) has also recently been used in preoperative planning. We sought to assess the accuracy of CT for localization of abnormal parathyroid glands in such patients.

METHODS

An audit of 75 patients with primary hyperparathyroidism (PHPT) who underwent neck US and CT between 2017 and 2019 at our center as their first-line imaging.

RESULTS

All 75 patients underwent US and CT and 54 (72.0%) also had sestamibi. CT alone identified a potential target in all patients, of which the location was correct in 63 (84.0%). The overall combined sensitivity of US and CT was 88% (95% CI 78-94) and was higher than the combined sensitivity of US and sestamibi (65% [95% CI 53-76]; p < 0.001). Twenty-one patients (28.0%) had an ectopic gland, and the sensitivity of US and CT was 86% (95% CI 64-96) versus US and sestamibi (57% [95% CI 34-77]; p = 0.016). For adenomas < 1.0 g (n = 36; 48%), the accuracy of CT was 81% (95% CI 64-91) compared with 62% (95% CI 44-77) for US and sestamibi (p = 0.04). The correct preoperative diagnosis of multiglandular disease (n = 9; 12%) seemed to be the most difficult, with similar accuracy for US and sestamibi (40% [95% CI 14-73]) and US and CT (50% [95% CI 20-80]) (p > 0.99).

CONCLUSION

The combination of US and CT was able to correctly identify the location of the abnormal parathyroid in 88% of patients and, in comparison with US and sestamibi, had better diagnostic accuracy, especially for smaller and ectopic adenomas. This finding suggests that US and CT could be considered as a first-line imaging modality in patients with PHPT considered for MIP.

Preoperative matching studies in the diagnosis of parathyroid adenoma for primary hyperparathyroidism: Can we avoid intraoperative PTH monitoring?

INTRODUCTION

We aim to determine the utility of intraoperative parathyroid hormone (IOPTH) monitoring in patients with matching preoperative ultrasound and mibi SPECT for primary hyperparathyroidism for a single adenoma.

METHODS

All patients who underwent minimally invasive parathyroidectomy (MIP) for pseudohypoparathyroidism (PHP) for a single parathyroid adenoma, were included. An Ultrasound and mibi SPECT were performed in all patients. We defined matching studies when both coincided in the localization of the adenoma. IOPTH was performed in all patients and analyzed in three occasions: a baseline measurement at the anesthetic induction, immediately before, and 15 min after gland excision. Success was defined during the third measurement as a drop of IOPTH of at least 50% compared to the previous maximum value after gland excision. Demographics, intraoperative, postoperative variables and the utility of IOPTH monitoring were analyzed.

RESULTS

A total of 218 MIP were performed. The average age was 60.1 years and 85% were female. Preoperative ultrasound and mibi SPECT coincided 100%. When the adenoma was localized, 15 min after its excision, IOPTH did not decrease in 9 patients (4.2%. OR 1.9%-7.69%); all of them underwent a bilateral neck exploration. The added-value of IOPTH accuracy for disease cure was 3.6%. There was a 99% of cure rate. The mean surgical time was 66.4 min and the waiting time for the third IOPTH result was 31 min. Performing IOPTH monitoring made the surgery about twice more expensive.

CONCLUSIONS

Preoperative matching ultrasound and mibi SPECT for parathyroid adenoma localization in PHP, could avoid IOPTH monitoring in minimally invasive parathyroidectomies.

Direct Comparison of Preoperative Imaging Modalities for Localization of Primary Hyperparathyroidism: A Systematic Review and Network Meta-analysis

Importance

Accurate preoperative localization of primary hyperparathyroidism (pHPT) is an important and challenging issue for a successful parathyroidectomy. Although new imaging modalities have been introduced during the past decade, direct comparative studies on advanced imaging techniques are limited.

Objective

To compare the performance of different preoperative imaging modalities for the localization of pHPT by performing a network meta-analysis (NMA).

Data Sources

PubMed, Embase, and the Cochrane Library were searched from the earliest available indexing date through September 28, 2020.

Study Selection

The inclusion criteria were diagnostic tests with sensitivities of 2 or more different preoperative imaging modalities for the same indivduals.

Data Extraction and Synthesis

Two researchers independently reviewed the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension statement of health care intervention guidelines for network meta-analyses.

Main Outcomes and Measures

After classifying various imaging modalities into 8 representative imaging categories, the pooled estimation between the odds ratio and 95% credible intervals (CrIs) was calculated in the sensitivity for localization of pHPT. The surface under the cumulative ranking curve (SUCRA) values were obtained to calculate the probability of each imaging modality being the most effective diagnostic method.

Results

A total of 8495 patients from 119 direct comparative studies using 2 or more imaging modalities for localization of pHPT were included. The sensitivity of choline positron emission tomography and computed tomography (PET-CT) was significantly higher than that of technetium 99m sestamibi single-photon emission computed tomography (MIBI SPECT) in both patient-based and lesion-based analyses (patient-based analysis: odds ratio, 5.22; 95% CrI, 2.36-11.80; lesion-based analysis: odds ratio, 17.70; 95% CrI, 5.79-60.10). Among 8 representative imaging modality categories, choline PET-CT showed the highest SUCRA value in both patient-based and lesion-based analyses. In patient-based analysis after 2010, choline PET-CT showed the highest SUCRA value, followed by the CT category, although MIBI SPECT had the highest SUCRA value in analysis before 2009.

Conclusions and Relevance

The results from this network meta-analysis suggest that choline PET-CT showed the best performance in both patient-based and lesion-based analyses and that choline PET-CT would be the best preoperative imaging modality for localization of pHPT.

A cost-utility analysis of 18F-fluorocholine-positron emission tomography imaging for localizing primary hyperparathyroidism in the United States

BACKGROUND

Primary hyperparathyroidism historically necessitated bilateral neck exploration to remove abnormal parathyroid tissue. Improved localization allows for focused parathyroidectomy with lower complication risks. Recently, positron emission tomography using radiolabeled 18F-fluorocholine demonstrated high accuracy in detecting these lesions, but its cost-effectiveness has not been studied in the United States.

METHODS

A decision tree modeled patients who underwent parathyroidectomy for primary hyperparathyroidism using single preoperative localization modalities: (1) positron emission tomography using radiolabeled 18F-fluorocholine, (2) 4-dimensional computed tomography, (3) ultrasound, and (4) sestamibi single photon emission computed tomography (SPECT). All patients underwent either focused parathyroidectomy versus bilateral neck exploration, with associated cost ($) and clinical outcomes measured in quality-adjusted life-years gained. Model parameters were informed by literature review and Medicare costs. Incremental cost-utility ratios were calculated in US dollars/quality-adjusted life-years gained, with a willingness-to-pay threshold set at $100,000/quality-adjusted life-year. One-way, 2-way, and threshold sensitivity analyses were performed.

RESULTS

Positron emission tomography using radiolabeled 18F-fluorocholine gained the most quality-adjusted life-years (23.9) and was the costliest ($2,096), with a total treatment cost of $11,245 or $470/quality-adjusted life-year gained. Sestamibi single photon emission computed tomography and ultrasound were dominated strategies. Compared with 4-dimentional computed tomography, the incremental cost-utility ratio for positron emission tomography using radiolabeled 18F-fluorocholine was $91,066/quality-adjusted life-year gained in our base case analysis, which was below the willingness-to-pay threshold. In 1-way sensitivity analysis, the incremental cost-utility ratio was sensitive to test accuracy, positron emission tomography using radiolabeled 18F-fluorocholine price, postoperative complication probabilities, proportion of bilateral neck exploration patients needing overnight hospitalization, and life expectancy.

CONCLUSION

Our model elucidates scenarios in which positron emission tomography using radiolabeled 18F-fluorocholine can potentially be a cost-effective imaging option for primary hyperparathyroidism in the United States. Further investigation is needed to determine the maximal cost-effectiveness for positron emission tomography using radiolabeled 18F-fluorocholine in selected populations.

Rapid intraoperative perfusion assessment of parathyroid adenomas with ICG using a wide-field portable hand-held fluorescence imaging system

BACKGROUND

Fluorescence angiography (FA) using indocyanine green dye (ICG) has recently been introduced for real-time identification of parathyroid adenomas. However, time to peak fluorescence has not yet been critically evaluated.

METHODS

This was a retrospective review of parathyroidectomies with ICG FA over a one-year period.

RESULTS

There were 66 patients with average age of 64 years. The average time to initial fluorescence was 26.7 s and to peak fluorescence was 38.0 s. The time to saline flush administration significantly correlated with times to initial and peak fluorescence (p < .0001). The rate of in-situ fluorescence was 97%. The rates of suspected adenoma detection were 69% for sestamibi scan, 71% for ultrasound, and 96% for CT scan. Imaging was discordant in 13 cases (20%), with the adenoma located on the opposite side of the neck in 4 cases.

CONCLUSIONS

ICG FA is a rapid and effective adjunct for the intraoperative identification of parathyroid adenomas.

Radioguided occult lesion localization for minimally-invasive parathyroidectomy without quick PTH monitoring and frozen section: impact of the learning curve

Objectives

Minimally-invasive parathyroidectomy (MIP) is a surgical procedure that reduces the duration of operation, hospital costs, and hypocalcemia, and shortens the length of hospital stay. This study addressed the important procedural details of the radioguided occult lesion localization (ROLL)-MIP technique and evaluated the consequences of the learning curve from a series of patients.

Patients and Methods

A total of 80 patients who underwent ROLL-MIP for a single parathyroid adenoma were included into this retrospective study. In order to analyze the effect of the learning curve, these subjects were then divided into 2 groups per time period and the operative times were compared. Group A consisted of 22 previously reported patients who served as the control group. Group B consisted of 58 consecutive patients.

Results

Serum calcium and parathyroid hormone (PTH) levels were normalized in all of the patients within 2 days and remained normal during the follow-up period (31 ± 18.5 months). None of the patients who underwent ROLL-guided parathyroidectomy suffered temporary or permanent recurrent laryngeal nerve injuries. Mean operation time (time from incision to excision of the adenoma) was 23 ± 6 min in Group A and 18 ± 7 min in Group B. Mean operative times were significantly shorter in group B.

Conclusion

The success of MIP administered with the ROLL technique in a single adenomatous patient was quite high. This method seems especially valuable in patients with atypically located or small adenomas.

Stepwise Approach for Parathyroid Localisation in Primary Hyperparathyroidism

INTRODUCTION

Primary hyperparathyroidism (PHPT) is a relatively common condition in surgical practice. Availability of localisation studies has shifted the treatment from bilateral neck exploration to selective parathyroidectomy. Several imaging modalities, each with varying sensitivities, are available to detect abnormal parathyroid glands. Ultrasound is almost universally accepted as the first line radiological investigation however its sensitivity is particularly heterogeneous and operator-dependent.

MATERIAL AND METHODS

We studied 250 consecutive patients with PHPT who underwent parathyroidectomy in our hospital over a period of 33 months. Pre-operative neck ultrasound, 99mTc-sestamibi and single-photon emission computed tomography (SPECT CT) were performed in 249, 237 and 198 patients respectively. Unilateral and bilateral neck exploration was performed in 190 and 60 patients, respectively. Sensitivity, positive predictive value (PPV) and accuracy were calculated comparing the results with surgical and pathology findings.

RESULTS

Mean pre and postoperative PTH and adjusted calcium were, 11 ± 10.6 pmol/L, 1.9 ± 3.6, 2.81 ± 0.2 and 2.45 ± 0.2 mmol/L. There were 71 (29.95%) discordant results between US, compared to sestamibi and SPECT CT. An average of 1.9 parathyroid glands were removed with a mean weight of 0.92 g. Overall success rate based on postoperative PTH levels was 94.8%. Overall sensitivity, PPV and accuracy for US were 80.80%, 92.35%, and 75.73% respectively; for sestamibi were 71.82%, 94.61%, 69.00% and for SPECT CT were; 70.21%, 97.78%, 69.11% respectively.

CONCLUSION

Ultrasound performed by an experienced specialist sonographer is highly sensitive in localising abnormal parathyroid glands. It can be used as a main and sole investigation in the majority of patients. Sestamibi, SPECT CT and other investigations should be performed in a step-wise manner and reserved for patients with negative US, failed primary procedure and recurrences.

Preoperative matching studies in the diagnosis of parathyroid adenoma for primary hyperparathyroidism: Can we avoid intraoperative PTH monitoring?

INTRODUCTION

We aim to determine the utility of intraoperative parathyroid hormone (IOPTH) monitoring in patients with matching preoperative ultrasound and mibi SPECT for primary hyperparathyroidism for a single adenoma.

METHODS

All patients who underwent minimally invasive parathyroidectomy (MIP) for pseudohypoparathyroidism (PHP) for a single parathyroid adenoma, were included. An Ultrasound and mibi SPECT were performed in all patients. We defined matching studies when both coincided in the localization of the adenoma. IOPTH was performed in all patients and analyzed in three occasions: a baseline measurement at the anesthetic induction, immediately before, and 15 minutes after gland excision. Success was defined during the third measurement as a drop of IOPTH of at least 50%compared to the previous maximum value after gland excision. Demographics, intraoperative, postoperative variables and the utility of IOPTH monitoring were analyzed.

RESULTS

A total of 218 MIP were performed. The average age was 60.1 years and 85% were female. Preoperative ultrasound and mibi SPECT coincided 100%. When the adenoma was localized, 15 minutes after its excision, IOPTH did not decrease in 9 patients (4.2% OR 1.9% - 7.69%); all of them underwent a bilateral neck exploration. The added-value of IOPTH accuracy for disease cure was 3.6%. There was a 99% of cure rate. The mean surgical time was 66.4 minutes and the waiting time for the third IOPTH result was 31minutes. Performing IOPTH monitoring made the surgery about twice more expensive.

CONCLUSIONS

Preoperative matching ultrasound and mibi SPECT for parathyroid adenoma localization in PHP, could avoid IOPTH monitoring in minimally invasive parathyroidectomies.

Imaging and choosing the right patients for transoral endoscopic parathyroidectomy vestibular approach

Advances in imaging for preoperative localization have propelled the widespread adoption of minimally invasive/focused parathyroidectomy in primary hyperparathyroidism. Though it is performed through a relatively small incision, studies have shown that the presence of a neck scar increases attentional bias towards the neck resulting in compromised quality of life. Transoral endoscopic parathyroidectomy vestibular approach (TOEPVA) eliminates a neck scar. While indications for TOEPVA are the same as that of minimally invasive open parathyroidectomy, confident preoperative localization of the parathyroid with a surgeon performed ultrasound along with concordant localization with SPECT CT is an essential prerequisite before offering patients this approach for parathyroidectomy. Early data has demonstrated the feasibility and safety of this approach.

Use of a Sestamibi-only Approach to Routine Minimally Invasive Parathyroidectomy

We performed this study to compare a sestamibi-only radio-guided approach (MIBI) versus using intraoperative parathyroid hormone monitoring (IOPTH) in the performance of minimally invasive parathyroidectomy (MIP) in patients with a clearly positive preoperative sestamibi scan from January 2000 to June 2010. Five of 81 patients in the MIBI group required additional surgery, three at the time of MIP when the intraoperative findings were in conflict with the preoperative sestamibi scan and two required a second operation as a result of an undiscovered second adenoma. In the IOPTH group, five patients had an unnecessary bilateral neck exploration as a result of an inadequate drop in PTH levels, whereas six had their disease cured because the PTH levels predicted additional pathology. One patient in the IOPTH group remains hypercalcemic and represents the only surgical failure in this study. The MIBI group had a shortened operating room time and less cost ( P < 0.001). No deaths or complications, including recurrent laryngeal nerve injuries, occurred in this study. Although both strategies are effective in managing hyperparathyroidism, a MIBI-only approach is less expensive and has shorter operative times with an occasional need for reoperation, whereas the IOPTH group results in more extensive surgery that will occasionally be unnecessary.

Actual role of color-doppler high-resolution neck ultrasonography in primary hyperparathyroidism: a clinical review and an observational study with a comparison of 99mTc-sestamibi parathyroid scintigraphy

PURPOSE

Primary hyperparathyroidism (PHPT) is a frequent endocrine pathology that has surgical treatment as its only decisive measure. High-Resolution Neck Ultrasonography with color-Doppler (CDHR-NUS) and 99mTechnetium-SestaMIBI Parathyroid Scintigraphy (99mTc-MIBI PS) are the two instrumental exams more commonly used in the preoperatory localization of pathologic parathyroids. The aim of this observational study was to outline-in accordance with the latest scientific literature-the precise role of CDHR-NUS in the environment of PHPT, comparing it with that of Parathyroid Scintigraphy.

METHODS

136 patients operated on for PHPT and underwent CDHR-NUS and 99mTc-MIBI PS preoperatively. The CDHR-NUS was carried out by an expert medical sonographer. The results of the two methods were compared between each other and with the results of the operative act for the evaluation of accordance and diagnostic performances.

RESULTS

PHPT is prevalently due to monoglandular pathology (SGD). The parallel use of CDHR-NUS and of 99mTc-MIBI PS does not determine a significant increase in diagnostic accuracy. The preoperative accordance evaluation between the two methods does not exclude the presence of multiglandular pathology (MGD) with certainty.

CONCLUSIONS

CDHR-NUS is an accurate as well as cost-effective method; its role as a main and eventual unique preoperative localization method in patients affected by PHPT is confirmed. In the presence of expert medical sonographers, the sequential use of the two methods is retained correct and their use in parallel is neither justified nor cost-effective. The preoperative accordance evaluation between the two methods is neither necessary nor indispensable.

Clinical Value of Tc99m-MIBI SPECT/CT Versus 4D-CT or US in Management of Patients With Hyperparathyroidism

Localization of parathyroid adenomas for treatment of primary hyperparathyroidism can be challenging. This retrospective study compared single-photon emission computed tomography/computed tomography (SPECT/CT), 4D-CT, and US studies in detection of adenomas prior to surgery. A retrospective chart review was performed on all consecutive patients with parathyroid adenoma presenting to an urban tertiary care medical center. A total of 58 patients (45 female, 13 male) underwent surgery for parathyroid adenoma. Patients aged 28 to 80 years (mean: 58.8) with parathyroid hormone levels ranging from 42 to 424 pg/mL (mean: 168). All patients underwent preoperative SPECT/CT with 20 mCi technetium-99m MIBI (^99mTc-MIBI). Fifty-three patients had additional US imaging and 14 patients had 4D-CT scans. Additionally, 34 patients had injection of 20 mCi ^99mTc-MIBI on the day of surgery. Pathological correlation was performed. Comparing SPECT/CT versus 4D-CT resulted in sensitivity (77% vs 80%), specificity (71% vs 75%), and accuracy (77% vs 79%). Ultrasound was less sensitive with similar specificity (44%, 86%, respectively). Combination of SPECT/CT and 4D-CT increased sensitivity to 88%, specificity to 100%, and accuracy to 89%. Combining SPECT/CT with US resulted in sensitivity of 85%, specificity of 83%, and accuracy of 85%. Intraoperative localization substantially improved in patients who received preoperative injections. The SPECT/CT remains the best imaging modality for preoperative localization of parathyroid adenomas with high sensitivity. Combining SPECT/CT with US resulted in increased sensitivity and accuracy. For suspicion of ectopic cases or suspicion of unidentifiable adenoma with negative scintigraphy, addition of 4D-CT is recommended. Intraoperative localization and adjunctive imaging may improve surgical management of patients with hyperparathyroidism.

The prevalence and anatomy of parathyroid glands: a meta-analysis with implications for parathyroid surgery

Purpose

The anatomy of parathyroid glands (PTG) is highly variable in the population. The aim of this study was to conduct a systematic analysis on the prevalence and location of PTG in healthy and hyperparathyroidism (HPT) patients.

Methods

An extensive search of the major electronic databases was conducted to identify all studies that reported relevant data on the number of PTG per patient and location of PTG. The data was extracted from the eligible studies and pooled into a meta-analysis.

Results

The overall analysis of 26 studies (n = 7005 patients; n = 23,519 PTG) on the number of PTG showed that 81.4% (95% CI 65.4–85.8) of patients have four PTG. A total of 15.9% of PTG are present in ectopic locations, with 11.6% (95% CI 5.1–19.1) in the neck and 4.3% (95% CI 0.7–9.9) in mediastinum. The subgroup analysis of ectopic PTG showed that 51.7% of ectopic PTG in the neck are localized in retroesophageal/paraesophageal space or in the thyroid gland. No significant differences were observed between the healthy and HPT patients and cadaveric and intraoperative studies.

Conclusions

Knowledge regarding the prevalence, location, and anatomy of PTG is essential for surgeons planning for and carrying out parathyroidectomies, as any unidentified PTG, either supernumerary or in ectopic location, can result in unsuccessful treatment and need for reoperation.

Electronic supplementary material

The online version of this article (10.1007/s00423-019-01751-8) contains supplementary material, which is available to authorized users.

Assessment of the role of early dynamic PET/CT with 18F-fluorocholine in detection of parathyroid lesions in patients with primary hyperparathyroidism

OBJECTIVE

The aim of the present study was to assess the utility of early dynamic PET/computed tomography with fluorine-18-fluorocholine (F-FCH) in detecting parathyroid lesions and in differentiating parathyroid lesions from cervical lymph nodes (LNs).

PATIENTS AND METHODS

A prospective study was conducted on 14 patients with clinical and biochemical evidence of primary hyperparathyroidism by having a positive Tc-sestaMIBI scan. Patients underwent early dynamic F-FCH PET/computed tomography scan, after the administration of 5-8 mCi (185-296 MBq) at 1 min per frame for 15 min. Delayed static images of 2-3 min per bed position were taken between 45 and 60 min. 3D-VOI's were plotted on parathyroid adenoma, cervical LN and thyroid. Dynamic and static images were interpreted by two expert nuclear medicine physicians independently and the following parameters were calculated for parathyroid adenoma and cervical LN: maximum standardized uptake value (SUVmax), time activity curve for SUVmax, t-peak. Adenoma to thyroid ratio (A/T) and cervical LN to thyroid ratio were calculated for each dynamic and static image.

RESULTS

Fourteen (eight females and six males) patients were included in the study. All patients showed a higher SUVmax in the adenoma and the cervical LN in the early dynamic images as compared with delayed static images. A/T ratio obtained in the dynamic and static images were compared and found to have insignificant difference (P=0.2255). The difference between mean A/T and LN to thyroid ratio was found to be significant (P=0.0117) during the dynamic study.

CONCLUSION

A possible explanation of higher SUVmax in the dynamic images in adenomas may be due to the increased vascularity/early F-FCH uptake. Results indicate early dynamic imaging could suffice, without the need for a delayed image after 45 min, and this technique could adequately differentiate a parathyroid adenoma from a cervical LN.

Diagnostic accuracy of parathyroid hormone levels in washout samples of suspicious parathyroid adenomas: A single-centre retrospective cohort study

INTRODUCTION

Minimally invasive surgery is an alternative surgical approach for primary hyperparathyroidism with less surgical trauma and anaesthesia complications. When combined with intraoperative measurement of parathyroid hormone (PTH), cure rates are exceeding 97%. Preoperative intact PTH determination in washout samples is really very useful when parathyroid lesions cannot be easily distinguished from thyroid lesions or sometimes lymph nodes. Herein, we aimed to report our institutional experience about parathyroid fine-needle aspiration (FNA) method and suggest a cut-off ratio for this purpose.

METHODS

In our clinic, we performed ultrasonography (USG)-guided parathyroid FNA procedure for 131 patients diagnosed with primary hyperparathyroidism between January 2005 and January 2016. Both cytologic evaluation and intact PTH determination were performed in washout samples. Eighty-seven of the study group also had a parathyroid scintigraphy. Both demographic features and laboratory results were all recorded.

RESULTS

Median serum PTH level was 142 (113-197), while mean PTH washout level was 1824 (0-3953). When three of the localization techniques are compared with each other, FNA-PTH washout group had a better diagnostic accuracy (90.8%) when compared to cytology (7.92%) and MIBI (67.8%) groups. Both MIBI and FNA-PTH washout group had 100% positive predictive value (PPV) and 100% specificity. We found values greater than 436.5 pg/mL for FNA-PTH washout with a sensitivity of 90.3% and specificity of 88.9% (P < 0.01 and AUC 94.3 (87.8-100)) and a cut-off for FNA/serum PTH greater than 3.05 with a sensitivity of 91.2% and specificity of 89% (P = 0.02 and AUC 94.5 (88.8-100)) which implicate parathyroid lesions.

CONCLUSION

According to the literature, PTH determination in washout samples has a specificity of 75%-100% and sensitivity of 70%-100%. This approach has better results than both cytology and scintigraphy in case of concomitant multinodular thyroid disease in experienced hands. Although there is not a definite cut-off for PTH levels in washout samples, we agree with the need of ratios rather than cut-offs in this issue.

Presentation, diagnostic assessment and surgical outcomes in primary hyperparathyroidism: a single centre's experience

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a common reason for referral to endocrinology but the evidence base guiding assessment is limited. We evaluated the clinical presentation, assessment and subsequent management in PHPT.

DESIGN

Retrospective cohort study.

PATIENTS

PHPT assessed between 2006 - 2014 (n = 611) in a university hospital.

MEASUREMENTS

Symptoms, clinical features, biochemistry, neck radiology and surgical outcomes.

RESULTS

Fatigue (23.8%), polyuria (15.6%) and polydipsia (14.9%) were associated with PHPT biochemistry. Bone fracture was present in 16.4% but was not associated with biochemistry. A history of nephrolithiasis (10.0%) was associated only with younger age (P = 0.006) and male gender (P = 0.037). Thiazide diuretic discontinuation was not associated with any subsequent change in calcium (P = 0.514). Urine calcium creatinine clearance ratio (CCCR) was <0.01 in 18.2% of patients with confirmed PHPT. Older age (P < 0.001) and lower PTH (P = 0.043) were associated with failure to locate an adenoma on ultrasound (44.0% of scans). When an adenoma was identified on ultrasound the lateralization was correct in 94.5%. Non-curative surgery occurred in 8.2% and was greater in those requiring more than one neck imaging modality (OR 2.42, P = 0.035).

CONCLUSIONS

Clinical features associated with PHPT are not strongly related to biochemistry. Thiazide cessation does not appear to attenuate hypercalcaemia. PHPT remains the likeliest diagnosis in the presence of low CCCR. Ultrasound is highly discriminant when an adenoma is identified but surgical failure is more likely when more than one imaging modality is required.

Accuracy of Neck Ultrasonography in Predicting the Size and Location of Parathyroid Adenomas

OBJECTIVES

Ultrasonography (US) is a reliable tool for the preoperative localization of parathyroid adenomas (PTAs). The aim of this study was to evaluate the accuracy of US for estimating both the size and the location of PTAs and the effect of operator expertise.

STUDY DESIGN

Retrospective cohort study.

SETTING

A single tertiary medical center.

SUBJECTS AND METHODS

All patients who underwent parathyroidectomy for primary hyperparathyroidism between 1996 and 2012 were included. The estimated PTA localization and size by preoperative ultrasound were compared with the intraoperative findings and pathology report.

RESULTS

The cohort included 410 patients. US correctly localized the adenoma in 76% of cases with a sensitivity of 76.2% and a positive predictive value of 86.8%. Measurements were least accurate for adenomas measuring <1 cm in diameter (24%). Scans made by a single senior operator specializing in the neck had a higher accuracy rate than scans made by multiple operators, with a significant difference for small adenomas ( P < .001).

CONCLUSIONS

US is an accurate and sensitive tool for evaluating PTA size and location. Neck US is less accurate for small adenomas (<1 cm). In these cases particularly, the experience and expertise of the US operator may play an important role.

Focused parathyroidectomy for single parathyroid adenoma: a clinical account of 20 patients

Background

Single parathyroid adenoma is the commonest cause of primary hyperparathyroidism. Localization of the affected gland preoperatively is a critical step in management. Surgery is considered as the main line of treatment for single parathyroid adenoma. Focused technique for parathyroid excision was found by many researchers to have a good success rate even without intraoperative parathyroid hormone measurement.

Objective

The aim of this study was to assess the feasibility, safety, and adequacy of focused parathyroidectomy via an open lateral approach using preoperative positive Sestamibi (MIBI) scan and/or ultrasound without utilizing any intraoperative aiding tools.

Methods

A case-series prospective analysis of focused open parathyroidectomy for 20 patients presented to the department of surgery or referred from the orthopedic department between October 2012 and January 2015 at the Faculty of Medicine, Al-Azhar University, Cairo, Egypt, diagnosed as sporadic hyperparathyroidism with either positive MIBI scan or ultrasound were done. Normalization of the postoperative levels of serum calcium and PTH was considered as a marker of success. Data entry and analysis were done using the IBM-SPSS version 22.

Results

In this study, focused minimal access parathyroidectomy was successful in 95% with no major surgical complications, i.e., recurrent laryngeal nerve palsy or permanent hypoparathyroidism. The patient’s mean age was 46.5±12 years. The preoperative serum calcium level ranged from 8.8 to 15.2 mg/dL. The parathyroid hormone level was elevated ranging from 123–2000 pg/mL. In 90% of the cases, serum levels of alkaline phosphatase were elevated, while serum phosphorus was low with range 1.5–4.7 mg/dL. The left inferior parathyroid gland was the most commonly involved gland (40%). Using ultrasound and Sestamibi scan for preoperative localization was accurate in 75% and 90%, respectively. When both techniques were combined localization accuracy increased to 95%.

Conclusion

Our study has shown that focused parathyroidectomy is considered as a good option for single gland disease even if there are no available intraoperative helping aids, provided that good patient selection is undertaken.

Non-functioning parathyroid cystic tumour: malignant or not? Report of a case

Parathyroid carcinoma (PC) is a very rare endocrine tumour, usually characterized by symptoms such as a neck mass, dysphonia, severe hypercalcemia exceeding 140 mg/L and elevated serum parathyroid hormone levels, even more than 5 times the upper limit of normal. Non-functioning parathyroid cancer is extremely rare and, in this case, its pre-operative diagnosis is often difficult. A 54-year old female patient, referring dysphagia and dysphonia, underwent neck ultrasound and neck CT. A left thyroid nodule, probably cystic, was found. It presented caudal extent on anterior mediastinum causing compression of the left lateral wall of the trachea. The preoperative calcemia was into the normal range. The patient underwent left thyroid lobectomy. Histological exam showed a cystic lesion, immunohistochemically originating from parathyroid that oriented for carcinoma. The 18 months follow-up did not show a residual-recurrent disease. The parathyroid origin of a neck lesion could not be suspected before surgery when specific laboratory tests are not available and clinical effects of hyperparathyroidism syndrome are not present. Histological features are not always sufficient for the differential diagnosis between the parathyroid adenoma and carcinoma. The immunohistochemistry is an useful tool that can aid to reach the definite diagnosis.

Primary hyperparathyroidism treated by transoral endoscopic parathyroidectomy vestibular approach (TOEPVA)

BACKGROUND

Bilateral open cervical exploration with identifying all parathyroid glands and removing one or more enlarged parathyroid tumor(s) was the standard of care in primary hyperparathyroidism (pHPT). With the introduction of preoperative imaging and intraoperative parathyroid hormone (IOPTH) measurements [1, 2], various minimally invasive parathyroidectomy approaches have been developed, both open and endoscopic [3-8]. The most commonly used approach currently in the USA is the minimally invasive open parathyroidectomy (MIP), which can be performed in the ambulatory setting with excellent cure and minimal complication rates [9-12]. However, the operation requires a cervical incision, with occasionally poor cosmesis. The transoral endoscopic parathyroidectomy vestibular approach (TOEPVA) provides a novel "scarless" approach to parathyroid surgery.

METHODS

The aim of the video is to provide detailed instruction of the TOEPVA in pHPT and how to interpret IOPTH measurements in this setting.

RESULTS

The TOEPVA uses three incisions in the vestibule of the oral cavity, using two 5-mm ports and one central 11-mm port. The subplatysmal space is enlarged by hydrodissection and manual dilation. The working space is enhanced by insufflation to 6 mmHg. With the adjunct of preoperative imaging and IOPTH measurements, the extent of the operation is tailored to achieve biochemical cure.

CONCLUSIONS

TOEPVA is feasible and safe and provides an excellent cosmetic outcome. It is a more direct approach than other remote endoscopic parathyroidectomy techniques. TOEPVA is an excellent option for select patients with pHPT wishing to avoid a neck incision.

Predictors of operative failure in parathyroidectomy for primary hyperparathyroidism

INTRODUCTION

Many adjuncts guide surgical decision making in parathyroidectomy, yet their independent associations with outcome are poorly characterized. We examined a broad range of perioperative factors and used multivariate techniques to identify independent predictors of operative failure (persistent disease) after parathyroidectomy.

METHODS

This was a retrospective review of 2239 patients with primary hyperparathyroidism who underwent parathyroidectomy at a single-center from 1999 to 2014. We used multivariate logistic regress to measure associations between multiple perioperative factors and an operative failure (persistent hypercalcemia).

RESULTS

Operative failure was identified in 67 patients (3.0%). The following variables were independently associated with operative failure on multivariate analysis: IOPTH criteria met (protective, OR = 0.22, P < 0.001), preoperative calcium (risk factor, OR = 2.27 per unit increase, P < 0.001), weight of excised gland(s) (protective, OR = 0.70 per two-fold increase, P = 0.003), and preoperative PTH (protective, OR = 0.55 per two-fold increase, P = 0.008).

CONCLUSION

In addition to the well-established IOPTH criteria, we suggest that consideration of the above independent perioperative risk factors may further inform surgical decision-making in parathyroidectomy.

Unilateral Exploration for Parathyroid Adenoma

Between January 2012 to 2016, 20 patients with primary hyperparathyroidism underwent surgical exploration for presumed diagnosis of parathyroid adenoma. Nineteen patients underwent ultrasonography of neck and USG was found to be accurate in localizing the adenoma in 84.2%. Seventeen patients underwent sestamibi isotope scanning and imaging correlated with operative findings in 94.1%. Combined accuracy of ulrasound and sestamibi scan which was done in 17 patients was 95%. Seventeen patients underwent unilateral exploration and there was resolution of disease in 94.1%. Three patients underwent bilateral exploration and had a success rate of 100% in the removal of offending adenoma. Fifteen minutes post excision, rapid intraoperative intact parathormone assay was sent in 14 out of 17 unilateral explorations and was found to have true positive rate of 93% and false positive rate of 7%. There was a significant difference in the operating time between unilateral (17 patients, mean operating time 1 h) and bilateral (3 patients, mean operating time 1¾ hrs) explorations. It is clear from this study; the preoperative localization of adenoma with plan for unilateral exploration with a combination of ultrasonography and sestamibi scan is extremely useful if unilateral exploration is planned for excision of parathyroid adenoma. However, the number of patients who underwent 15 min post excision intact parathormone assay, is a small number to comment on its usefulness in predicting the success of unilateral exploration.

A case report of mediastinal ectopic parathyroid adenoma presented as parathyroid crisis localized by SPECT/CT

INTRODUCTION

Parathyroid crisis due to ectopic parathyroid adenomas can pose diagnostic and management challenges, since it is quite rare in clinical practice.

CLINICAL FINDINGS/PATIENT CONCERNS

A 67-year-old Chinese male presented as a parathyroid crisis due to an ectopic mediastinal parathyroid adenoma with his serum calcium and PTH markedly increased in short time. An ultrasonography and computed tomography (CT) scan of the neck did not reveal any parathyroid adenoma. Thoracic CT detected a contrast-enhanced mass in the mediastinum. Although the ectopic location is difficult to appreciate on anterior planar technetium-99m-sestamibi scintigraphy views but has been accurately localized with single photon-emission computed tomography/computed tomography. After fluid resuscitation, loop diuretic, and calcitonin treatment, a thoracoscope surgery was performed. The histopathology of the mediastinal nodule was consistent with a parathyroid adenoma. Hypocalcemia due to hungry bone syndrome occurred after surgery and was resolved quickly with large-dose calcium and calcitriol supplementation. He is asymptomatic and has normal serum calcium and PTH levels on regular follow-up.

DIAGNOSES

The ultrasonography, CT, sestamibi, and single photon-emission computed tomography/computed tomography provide limited sensitivity in the detecting ectopic parathyroid adenomas alone. The combination of these techniques has incremental value in localizing ectopic parathyroid adenomas over either technique alone.

CONCLUSION

Any parathyroid crisis without parathyroid adenoma in the neck should alert physicians to search for ectopic locations through combination of imaging techniques.

Cost-benefit analysis of the intraoperative parathyroid hormone assay in primary hyperparathyroidism

BACKGROUND

The purpose of this study was to evaluate the usefulness of the routine intraoperative intact parathyroid hormone (IOPTH) assay, the role of unilateral and bilateral cervical exploration and of preoperative imaging, and to do a cost-benefit analysis in parathyroidectomy for primary hyperparathyroidism.

METHODS

Two hundred sixty-four patients who underwent operations between January 2000 and March 2015 were retrospectively divided into 2 groups.

RESULTS

Group A (IOPTH) was composed of 64 patients. Ultrasonography and technetium-99m-sestamibi (MIBI) identified the adenoma in 38 cases. Bilateral exploration was performed in 43 patients; of which 2 failures occurred. The IOPTH false-negative rate was 18.4%. The average cost was €1297.30. Group B (without IOPTH) was composed of 200 patients. Ultrasonography and MIBI identified the adenoma in 113 cases. Bilateral exploration was performed in 129 patients; of which 2 failures occurred. The average cost was €618.75.

CONCLUSION

The IOPTH assay should be used only in few selected cases because of its high cost. The experience of the team is essential to obtain a high cure rate. © 2016 Wiley Periodicals, Inc. Head Neck 39: 241-246, 2017.

Iodine 125 Seed for Localization in Primary Hyperparathyroidism

Background. Preoperative localization of the parathyroid gland prior to a minimally invasive parathyroidectomy (MIP) is important because of varying locations of the parathyroid gland. Several methods have been described to localize the affected gland. One novel technique is the use of an iodine 125 (I-125) seed as a marker. The aim of this study is to evaluate the feasibility of using an I-125 seed in localizing the diseased parathyroid gland prior to MIP. Materials and methods. This is a pilot study of 10 patients performed in the Amphia Hospital, the Netherlands. Patients in whom primary hyperparathyroidism (PHPT) was diagnosed in combination with 1 enlarged parathyroid gland on ultrasound (US) and scintigraphy and who were eligible for MIP were included in this study. These patients underwent a preoperative US-guided I-125 seed placement in the affected parathyroid gland. The main study parameters were the feasibility of the placement, intraoperative localization of the diseased gland and complications. Results. A total of 10 patients were included. The US-guided I-125 placement in the affected parathyroid gland was technically feasible in the majority of cases. Because of the anatomical location of the gland, the placement was difficult in 2 patients, resulting in suboptimal position and possible misplacement of the marker. MIP was uncomplicated in most cases. Complications during surgery were mainly intraoperative bleeding. Conclusions. The use of an I-125 seed for preoperative localization in PHPT is a relatively safe technique in parathyroid surgery. More research is needed to compare this technique with other preoperative localization techniques.

Surgical treatment of primary hyperparathyroidism due to parathyroid tumor: A 15-year experience

The aim of this study was to highlight our experience over a 15-year period in dealing with primary hyperparathyroidism (PHPT) due to a parathyroid tumor. Parathyroidectomy is the standard therapy for patients with PHPT. Our study included all patients with PHPT treated by parathyroidectomy at the Affiliated Cancer Hospital of Zhengzhou University, China. Between 1998 and 2013, a total of 107 patients were recruited. Their clinical data, presentation, laboratory examinations, imageological diagnoses and surgical approaches were analyzed retrospectively. Eighty-four cases (78.5%) were followed up. During a median follow-up period of 5.7 years, a total of 80 patients were without recurrence and metastasis. The main symptoms of PHPT patients were palpable neck mass, joint pains and pathological fracture. The high levels of preoperative parathyroid hormone (PTH) and serum calcium in PHPT patients decreased to below the normal upper limit within 3 days of surgery. The sensitivity of neck ultrasonography, sestamibi scanning, CT, MRI and the combination of three or four types of test were 86.0%, 90.4%, 80.8%, 79.6% and 96.1%, respectively. A 50% or greater drop in PTH levels within 20 min compared with the highest PTH levels before surgery occurred in 95/107 cases (88.8%). Transient hypocalcemia was the most common surgical complication. The ultrasonography and sestamibi scan is the most effective examination for parathyroid tumor. The 20 min PTH measurement appears to be extremely useful, and avoids unnecessary bilateral exploration.

Predictive Value of Parathyroid Scintigraphy in the Preoperative Evaluation of Patients with Primary Hyperparathyroidism

Background and Aims:

The surgical gold standard in primary hyperparathyroidism was until recently exploration of all four parathyroid glands. Today more patients undergo minimal invasive procedures demanding more accurate preoperative localization studies. The aim of the study was to determine the positive predictive value (PPV) of parathyroid scintigraphy (PS) and to some extent ultrasonography (US), defined as the probability of finding one single adenoma on the affected side at surgery when the scans had shown one single focus.

Material and Methods:

Eighty-eight surgically treated patients (76 women and 12 men, 8 with multiglandular disease) were included. The PS consisted of 99mTc-sestamibi scan with dual-phase technique, both planar and SPECT imaging, followed by 99mTc-pertechnetate scan. A positive scan was defined as a single focus accumulating sestamibi. Focal lesions on US were defined as hypoechoic nodules.

Results:

PS was positive in 80 patients. Seventy-nine had only one focus, of which 64 were correctly localized adenomas (PPV 81%). Forty-seven of 77 US examinations were positive. In 44 there was only one focus of which 38 were correctly localized (PPV 86%). PPV was 97% when both examinations were positive.

Conclusions:

Both PS and US have acceptably high PPVs defined as the ability to predict whether or not one single focus represents a parathyroid adenoma. Concordant positive results were accompanied by a PPV close to 100%.

ROLE OF IMAGING TESTS FOR PREOPERATIVE LOCATION OF PATHOLOGIC PARATHYROID TISSUE IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM

OBJECTIVE

Primary hyperparathyroidism (PHPT) can be cured by parathyroidectomy, and the preoperative location of enlarged pathologic parathyroid glands is determined by imaging studies, especially cervical ultrasonography and scintigraphy scanning. The aim of this retrospective study was to evaluate the use of preoperative cervical ultrasonography and/or parathyroid scintigraphy in locating pathologic parathyroid tissue in a group of patients with PHPT followed in the same endocrine center.

METHODS

We examined the records of 61 patients who had undergone parathyroidectomy for PHPT following (99m)Tc-sestamibi scintigraphy scan and/or cervical ultrasonography. Scintigraphic and ultrasonographic findings were compared to histopathologic results of the surgical specimens.

RESULTS

Ultrasonography detected enlarged parathyroid glands in 87% (48/55) of patients with PHPT and (99m)Tc-sestamibi scintigraphy in 79% (37/47) of the cases. Ultrasonography was able to correctly predict the surgical findings in 75% (41/55) of patients and scintigraphy in 72% (34/47). Of 7 patients who had negative ultrasonography, scintigraphy correctly predicted the surgical results in 2 (29%). Of 10 patients who had negative scintigraphy, ultrasonography correctly predicted the surgical results in 4 (40%). When we analyzed only patients with solitary eutopic parathyroid adenomas, the predictive positive values of ultrasonography and scintigraphy were 90% and 86%, respectively.

CONCLUSION

Cervical ultrasonography had a higher likelihood of a correct positive test and a greater predictive positive value for solitary adenoma compared to (99m)Tc-sestamibi and should be used as the first diagnostic tool for preoperative localization of affected parathyroid glands in PHPT.

ABBREVIATIONS

Ca = calcium IEDE = Instituto Estadual de Diabetes e Endocrinologia Luiz Capriglione PHPT = primary hyperparathyroidism PTH = parathyroid hormone.

The utility of indocyanine green near infrared fluorescent imaging in the identification of parathyroid glands during surgery for primary hyperparathyroidism

BACKGROUND AND OBJECTIVES

Intraoperative adjuncts for the localization of parathyroid glands in parathyroid surgery are limited. The aim of this study is to assess the usefulness of indocyanine green (ICG) near-infrared (NIR) fluorescent imaging in patients undergoing surgery for primary hyperparathyroidism (PHPT).

METHODS

ICG imaging was performed in 33 patients undergoing parathyroidectomy (PTX). Thyroid and parathyroid ICG uptake were assessed and independently verified on a grading scale. Clinical variables were recorded and analyzed for factors associated with ICG uptake.

RESULTS

Of 112 glands identified by naked eye, 104 (92.9%) demonstrated ICG uptake. Concomitant ICG fluorescence was identified in the thyroid in all patients. There was a trend toward increased ICG fluorescence in patients <60 years of age (P = 0.05). A higher degree of fluorescence was seen in patients presenting with pre-operative calcium values >11 mg/dl (P = 0.04) and in those parathyroids larger than 10 mm (P < 0.01). All patients had biochemically proven cure. No patients who underwent subtotal PTX (n = 6) developed postoperative hypoparathyroidism.

CONCLUSION

ICG can reliably localize parathyroid glands during PTX and additionally allow for assessment of parathyroid perfusion in patients undergoing subtotal resection. Concomitant fluorescence of the thyroid gland limits ICG's usefulness in directing the course of PTX. J. Surg. Oncol. 2016;113:771-774. © 2016 Wiley Periodicals, Inc.

Focused parathyroidectomy without intra-operative parathormone monitoring: The value of PTH assay in preoperative ultrasound guided fine needle aspiration washout

Background

The accurate identification of hyperfunctioning parathyroid (HP) gland is the only issue for definitive surgical treatment in primary hyperparathyroidism (pHPT). Various imaging and operative techniques have been proposed to confirm the localization of the diseased gland. Nevertheless, none of these methods proved to be the gold standard. The presented study aimed to assess the value of parathyroid hormone assay in preoperative ultrasound guided fine needle aspiration (FNA)-PTH washout fluid to verify the correct localisation for focused parathyroidectomy without intra-operative PTH monitoring.

Material and Methods

The retrospective analysis of 57 patients with pHPT who underwent FNA-PTH was conducted from a prospective database. Biochemical assessment together with radiological (ultrasonography) and nuclear (MIBI scan) imaging was reviewed. Associations between FNA-PTH washout values and localization technics were evaluated and compared in terms of operative findings.

Results

Focused parathyroidectomy without intraoperative PTH monitoring was performed to 45 patients with high FNA-PTH values. The median largest diameter of the target parathyroid lesion identified by ultrasonography was 13 mm (range, 6 to 36). The median serum PTH level was 190 pg/mL (range, 78 to 1709; reference range, 15 to 65) whereas the median washout PTH was 2500 pg/mL (range, 480 to 3389). According to operative findings high FNA-PTH levels correctly identified parathyroid adenoma in 40 cases (89% of sensitivity and 100% of specificity and positive predictive value) whereas MIBI scan localized the lesion in 36 of these cases (80% of sensitivity).

Conclusions

The higher level of PTH in preoperative ultrasound guided FNA washout is a considerable data to predict the correct localization of HP, particularly in circumstances of greater values than the serum PTH level. However, although its specificity is high, in cases of coexisting nodular thyroid disease, associated additional HP might be missed at focused parathyroidectomy without PTH monitoring, leading to recurrent disease.

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Preoperative FNA-PTH washout and intraoperative US together give accurate information about localization of parathyroid adenomas.

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In this circumstances, focused parathyroidectomy without intraoperative PTH monitoring might be feasible and successful.

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Nevertheless, misdiagnosis due to concomitant nodular thyroid disease is a fact that always merit consideration.

The role of ultrasound and nuclear medicine methods in the preoperative diagnostics of primary hyperparathyroidism

Primary hyperparathyroidism (PH) represents one of the most common endocrine diseases. In most cases, the disorder is caused by parathyroid adenomas. Bilateral neck exploration has been a widely used treatment method for adenomas since the 20's of the twentieth century. In the last decade, however, it has been increasingly replaced by a minimally invasive surgical treatment. Smaller extent, shorter duration and lower complication rate of such a procedure are emphasized. Its efficacy depends on a precise location of parathyroid tissue during the preoperative imaging. Scintigraphy and ultrasound play a major role in the diagnostic algorithms. The efficacy of both methods has been repeatedly verified and compared. The still-current guidelines of the European Association of Nuclear Medicine (2009) emphasize the complementary role of scintigraphy and ultrasonography in the preoperative diagnostics in patients with primary hyperparathyroidism. At the same time, attempts are made to improve both these techniques by implementing new study protocols or innovative technologies. Publications have emerged in the recent years in the field of ultrasonography, whose authors pointed out the usefulness of elastography and contrast media. Nuclear medicine studies, on the other hand, focus mainly on the assessment of new radiotracers used in the positron emission tomography (PET). The aim of this article is to present, based on literature data, the possibilities of ultrasound and scintigraphy in the preoperative diagnostics in patients with primary hyperparathyroidism. Furthermore, the main directions in the development of imaging techniques in PH patients were evaluated.