Imaging of the parathyroid glands in primary hyperparathyroidism

[18F]fluorocholine PET vs. [99mTc]sestamibi scintigraphy for detection and localization of hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism: outcomes and resource efficiency

BACKGROUND

Minimally invasive parathyroidectomy is the treatment of choice in patients with primary hyperparathyroidism (PHP), but it needs a reliable preoperative localization method to detect hyperfunctioning parathyroid tissue. Higher sensitivity and lower radiation exposure was demonstrated for [18F]fluorocholine PET/CT (FCh-PET/CT) in comparison to [99mTc]sestamibi (MIBI) scintigraphy. However, data of its efficiency in resource use and patient outcomes is lacking. The aim of our study was to determine the resource efficiency and patient outcomes of FCh-PET/CT in comparison to conventional MIBI scintigraphy.

PATIENTS AND METHODS

A group of 234 patients who underwent surgery after MIBI scintigraphy was compared to a group of 163 patients who underwent surgery after FCh-PET/CT. The whole working process from the implementation of imaging to the completion of surgical treatment was analyzed. The economic burden was expressed in the time needed for the required procedures.

RESULTS

The time needed to perform imaging was reduced by 83% after FCh-PET/CT in comparison to MIBI scintigraphy. The time needed to perform surgery was reduced by 41% when intraoperative parathyroid hormone monitoring was not used. There was no significant difference in the time of surgery between FCh-PET/CT and MIBI scintigraphy.

CONCLUSIONS

FCh-PET/CT reduces the time of imaging, the time of surgery and potentially reduces the number of reoperations for persistent disease.

Acute hypercalcemic crisis: A narrative review with a focus on pregnancy

A hypercalcemic crisis is a rare therapeutic emergency. However, it should not be overlooked, particularly during pregnancy, as it is associated with significant maternal and fetal morbidity and mortality. The most frequent etiology, including in pregnant women, is primary hyperparathyroidism. Knowledge of calcium-phosphate metabolism during pregnancy is important for understanding and interpreting the clinicopathological abnormalities observed in parathyroid pathology. Despite the expert consensus statement on parathyroid pathology issued by the European Society of Endocrinology, management of hypercalcemic crises remains poorly codified, particularly in pregnant women. Diagnostic examinations and hypocalcemia treatments are generally not recommended during pregnancy; however, it may be necessary to optimize preparation for surgery. Notably, surgery is the treatment of choice, particularly during pregnancy, when it should ideally be performed during the 2nd trimester. Therefore, a multidisciplinary approach is necessary. A consensus among European experts recommends systematic early detection of hypercalcemia during early pregnancy.

Ultrafast intraoperative parathyroid hormone monitoring system: prospective, multicentre, clinical validity study

BACKGROUND

Intraoperative parathyroid hormone (PTH) monitoring is a proven and reliable adjunct to parathyroid surgery, able to improve the outcomes and efficiency of the diagnostic and therapeutic pathway for patients with primary hyperparathyroidism. This study evaluated the innovative, compact, fully automated NBCL CONNECT Analyzer, which can measure whole-blood PTH in 5 min.

METHODS

A prospective multicentre study was conducted in stages: results reviews, recommendations, and implementation of improvements to the mechanical design, components of cartridges, calibration, and sampling protocols. Patients undergoing parathyroidectomy had PTH levels measured on the Analyzer and main laboratory platforms, either Roche or Abbott. The Miami criterion of a 50% drop in PTH concentration was used to define biochemical cure during surgery, and normal postoperative calcium level as cure of primary hyperparathyroidism. Measurements on the Analyzer were done by laboratory staff in London and nurses in Stuttgart. The Pearson coefficient (R) and Wilcoxon test were used for statistical analysis.

RESULTS

Some 234 patients (55 male, 179 female) with a median age of 58.5 (age full range 15-88) years underwent parathyroidectomy (195 minimally invasive, 38 bilateral neck exploration, 1 thoracoscopic; 12 conversions) for primary hyperparathyroidism between November 2021 and July 2022. Primary hyperparathyroidism was cured in 225 patients (96.2%). The sensitivity, specificity, and overall accuracy of the Analyzer assay in predicting biochemical cure were 83.9, 100, and 84.8% in phase 1; 91.2, 100, and 91.3% in phase 2; and 98.6, 100, and 98.6% in phase 3. There were no false-positive results (positive predictive value 100%). Correlations between Analyzer measurements and those obtained using the Roche device were very strong (R = 0.98, P < 0.001 in phase 1; R = 0.92, P < 0.001 in phase 2; R = 0.94, P < 0.001 in phase 3), and correlations for Analyzer readings versus those from the Abbott platform were strong (R = 0.82, P < 0.001; R = 0.89, P < 0.001; R = 0.91, P < 0.001). The Analyzer showed continued good mechanical performance, with stable and repeatable operations (calibrations, quality controls). Introducing a stricter sampling protocol and improvements in the clot-detecting system led to a decrease in the number of clotted samples and false-negative results. Outcomes were not affected by measurements performed either by nurses or laboratory staff.

CONCLUSION

Intraoperative PTH monitoring during parathyroid surgery can be done accurately, simply, and quickly in whole blood using the Analyzer.

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.

The Utility of 4D-CT Imaging in Primary Hyperparathyroidism Management in a Low-Volume Center

Background: Ultrasonography (US) and the 99mTc-sestamibi parathyroid scan (SPS) may have suboptimal accuracy when detecting the localization of enlarged parathyroid gland(s) (PTG). Therefore, the more accurate four-dimensional computed tomography scan (4D-CT) has been employed for PTG imaging. Currently, there is a paucity of data evaluating the utility of 4D-CT in low caseload settings. Aim and Objectives: To evaluate the impact of PTG imaging, using 4D-CT in conjunction with its intraoperatively displayed results, on the outcomes of surgical PTX. Materials and Methods: A single-center retrospective analysis of surgically treated patients with pHPT from 01/2010 to 01/2021 was conducted. An evaluation of the impact of the preoperative imaging modalities on the results of surgical treatment was carried out. Results: During the study period, 290 PTX were performed; 45 cases were excluded due to surgery for secondary, tertiary or recurrent HPT, or due to the use of alternative imaging techniques. The remaining 245 patients were included in the study. US was carried out for PTG imaging in 236 (96.3%), SPS in 93 (38.0%), and 4D-CT in 52 patients (21.2%). The use of 4D-CT was associated with a significantly higher rate of successful localization of enlarged PTG (49 cases, 94.2%) compared to US and SPS (74 cases, 31.4%, and 54 cases, 58.1%, respectively). We distinguished between three groups of patients based on preoperative imaging: (1) PTG lateralization via US or SPS in 106 (43.3%) cases; (2) precise localization of PTG via 4D-CT in 49 (20.0%) patients; and (3) in 90 cases (36.7%), PTG imaging failed to localize an enlarged gland. The group of 4D-CT localization had significantly shorter operative time, lower rate of simultaneous thyroid resections, as well as lower rate of removal of ≥2 PTG, compared to the other groups. The 4D-CT imaging was also associated with the lowest perioperative morbidity and with the lowest median PTH in the one month follow-up; however, compared to the other groups, these differences were statistically not significant. The implementation of 4D-CT (since 01/2018) was associated with a decrease in the need for redo surgery (from 11.5% to 7.3%) and significantly increased the annual case load of PTX at our institution (from 15.3 to 41.0) compared to the period before 4D-CT diagnostics. Conclusions: 4D-CT imaging enabled to precisely locate almost 95% of enlarged PTG in patients with pHPT. Accurate localization and intraoperatively displayed imaging results are useful guides for surgeons to make PTX a faster and safer procedure in a low-volume center.

Differences in the Presentation and Outcome between Premenopausal and Postmenopausal Primary Hyperparathyroidism Indian Women: A Single-Center Experience

Introduction

Primary hyperparathyroidism (PHPT) is an endocrine disorder wherein enlargement of one or more of the parathyroid glands causes autonomous overproduction of the parathyroid hormone (PTH), which leads to high serum calcium levels.

Objective

The objective of this study was to compare the clinical, laboratory, and operative variables between premenopausal (pre-M) and postmenopausal (post-M) women with PHPT.

Materials and Methods

A retrospective analysis of the data of female patients who underwent surgery for PHPT at a single center, from January 2011 to December 2020, was done. Patients with familial PHPT and secondary hyperparathyroidism were not included.

Results

Of the 130 women with PHPT, 44.6% were pre-M and 55.4% were post-M. A significantly higher number of pre-M females were symptomatic compared to post-M females (pre-M vs. post-M, 84.5% vs. 68.1%, P = 0.031). Renal calculi were more common in pre-M women (34.5% vs. 18.1%, P = 0.032), while the rest of the clinical features were comparable between the two groups. The proportion of women with osteoporosis (6.7% vs. 19.4%, P = 0.071), hypertension (13.8% vs. 34.7%, P = 0.012), and diabetes mellitus (3.5% vs. 16.7%, P = 0.033) was lesser in the pre-M group. Elevated serum alkaline phosphatase levels were significantly more prevalent in the pre-M group (37.9% vs. 20.8%, P = 0.032). The mean serum calcium (12.35 ± 1.28 vs. 11.96 ± 1.22 mg/dL, P = 0.079), median serum PTH (334 vs. 239 pg/mL, P = 0.051), and median weight of the operated adenomas (1.75 vs. 1.45 g, P = 0.075) were also higher in pre-M females. The proportion of ectopic adenomas and multiple adenomas, presurgery adenoma localization rates, and disease cure rates did not differ according to the menopausal status. The occurrence of postoperative hungry bone syndrome was higher in the pre-M women (15.5% vs. 1.4%, P = 0.008).

Conclusion

The majority of women with PHPT are post-M, but symptomatic presentation is more common in pre-M females. The severity of the disease appears to be more in pre-M women; however, imaging and operative variables generally did not significantly differ between the two groups.

Multi-modality parathyroid imaging: A shifting paradigm

The goal of parathyroid imaging in hyperparathyroidism is not diagnosis, rather it is the localization of the cause of hyperparathyroidism for planning the best therapeutic approach. Hence, the role of imaging to accurately and precisely localize the abnormal parathyroid tissue is more important than ever to facilitate minimally invasive parathyroidectomy over bilateral neck exploration. The common causes include solitary parathyroid adenoma, multiple parathyroid adenomas, parathyroid hyperplasia and parathyroid carcinoma. It is highly imperative for the radiologist to be cautious of the mimics of parathyroid lesions like thyroid nodules and lymph nodes and be able to differentiate them on imaging. The various imaging modalities available include high resolution ultrasound of the neck, nuclear imaging studies, four-dimensional computed tomography (4D CT) and magnetic resonance imaging. Contrast enhanced ultrasound is a novel technique which has been recently added to the armamentarium to differentiate between parathyroid adenomas and its mimics. Through this review article we wish to review the imaging features of parathyroid lesions on various imaging modalities and present an algorithm to guide their radiological differentiation from mimics.

Application value of contrast-enhanced ultrasound in preoperative localization of microwave ablation for primary hyperparathyroidism

BACKGROUND

Ultrasonography (US) and ^99m Technetium-sestamibi scintigraphy (^99m Tc-MIBI) are currently first-line imaging modalities to localize parathyroid adenomas with sensitivities of 80% and 84%, respectively. Therefore, finding other modalities to further improve the diagnostic accuracy for preoperative localization is critically needed.

PURPOSE

To evaluate the application value of contrast-enhanced ultrasound (CEUS) in the preoperative localization of microwave ablation (MWA) for primary hyperparathyroidism (PHPT).

METHODS

Between December 2012 and May 2021, 100 PHPT patients (34 males and 66 females; mean age, 56.31 ± 13.43 years; age range, 25-85 years) with 130 suspected parathyroid nodules were enrolled. US, CEUS, and ^99m Tc-MIBI were performed for the localization of pathological parathyroid glands. All patients were performed MWA under ultrasound guidance. All the suspected parathyroid nodules underwent core needle biopsy under ultrasound guidance during MWA to confirm the pathology. The diagnostic performance of all the imaging tests was analyzed in comparison with the pathological results.

RESULTS

A total of 130 nodules suspected to be of parathyroid origin from preoperative localization images were confirmed by pathological results, of which 116 were of parathyroid origin, and 14 were not of parathyroid origin. The sensitivity, specificity, accuracy, and the area under receiver operating characteristic curve of CEUS in the localization of pathological parathyroid glands were 100%, 92.86%, 99.23%, and 0.964, which were significantly higher than those of US (93.10%, 42.86%, 87.69%, and 0.680) and ^99m Tc-MIBI (81.90%, 42.86%, 77.69%, and 0.624) (p < 0.05). The sensitivity and accuracy of CEUS were 100% and 97.22%, which were higher than those of ^99m Tc-MIBI (65.62% and 63.89%) or US (75.00% and 72.22%) in patients with multiple parathyroid glands (p < 0.05). For smaller parathyroid adenomas (≤2 cm in diameter), the sensitivities of CEUS in locating hyperfunctioning parathyroid glands were 100%, which was significantly higher than that of ^99m Tc-MIBI (73.68% and 84.31%, p < 0.05).

CONCLUSIONS

CEUS is a valuable preoperative localization method for PHPT patients performed MWA, especially for the patients with smaller pathological parathyroid gland and multiple glandular lesions.

Accuracy of Parathyroid Adenoma Localization by Preoperative Ultrasound and Sestamibi in 1089 Patients with Primary Hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (pHPT) is well treatable surgically. Sonography (US) and sestamibi scintigraphy (MIBI) are used routinely, but it is unclear how valuable they are in determining Parathyroid glands' different locations. This study aimed to evaluate the prognostic value of US and MIBI in relation to the different localization of parathyroid adenomas in one of the largest study populations analyzed to date.

METHODS

1089 patients with pHPT who had treatment in one tertiary referral center between 2007 and 2016 were analyzed. Preoperative US and MIBI reports were compared with the parathyroid adenoma's intraoperative localization. All parathyroid glands were confirmed by histological diagnosis.

RESULTS

No gland was detectable in 22.5% and 27.7% of all patients, by US or by MIBI, respectively. In relation to the different adenoma locations, the sensitivity of US ranged from 21.3% (upper right) to 68.9% (lower left) and of MIBI ranged from 23.5% (upper right) to 72% (lower left). The specificity for US ranged from 85% (lower right) to 99.2% (upper right) and for MIBI ranged from 86.1% (lower right) to 99.1% (upper right. Positive predictive values for all gland sites were 54% and 59% for MIBI and US, respectively. The value increased for side-only prediction to 73% and 78%, respectively. Neither the parathyroid hormone level nor the calcium value level influenced the sensitivity or specificity of the two test methods.

CONCLUSIONS

The validity of preoperative US and MIBI depends crucially on the specific localization of adenomas. This should be considered when planning the extent of parathyroid surgery.

Preoperative Imaging with [18F]-Fluorocholine PET/CT in Primary Hyperparathyroidism

Primary hyperparathyroidism (pHPT) is a common endocrine disorder due to hyperfunctioning parathyroid glands. To date, the only curing therapy is surgical removal of the dysfunctional gland, making correct detection and localization crucial in order to perform a minimally invasive parathyroidectomy. ¹⁸F-Fluorocholine positron emission tomography/computed tomography (¹⁸F-FCH PET/CT) has shown promising results for the detection of pHPT, suggesting superiority over conventional imaging with ultrasounds or scintigraphy. A total of 33 patients with pHPT who had negative or equivocal findings in conventional imaging received ¹⁸F-FCH PET/CT preoperatively and were retrospectively included. A pathological hyperfunctional parathyroid gland was diagnosed in 24 cases (positive PET, 72.7%), 4 cases showed equivocal choline uptake (equivocal PET, 12.1%), and in 5 cases, no enhanced choline uptake was evident (negative PET, 15.2%). Twelve of the twenty-four detected adenoma patients underwent surgery, and in all cases, a pathological parathyroid adenoma was resected at the site detected by PET/CT. Two of the six patients without pathological choline uptake who received a parathyroidectomy revealed no evidence of parathyroid adenoma tissue in the histopathological evaluation. This retrospective study analyzes ¹⁸F-FCH PET/CT in a challenging patient cohort with pHPT and negative or equivocal conventional imaging results and supports the use of ¹⁸F-FCH for the diagnosis of hyperfunctional parathyroid tissue, especially in this patient setting, with a 100% true positive and true negative detection rate. Our study further demonstrates the importance of ¹⁸F-FCH PET/CT for successful surgical guidance.

Parathyroid 4D CT in Primary Hyperparathyroidism: Exploration of Size Measurements for Identifying Multigland Disease and Guiding Biochemically Successful Parathyroidectomy

BACKGROUND. In patients with primary hyperparathyroidism (PHPT), bilateral neck exploration is necessary for multigland disease (MGD), whereas minimally invasive parathyroidectomy is often preferred for single-gland disease (SGD). An existing system (the 4D-CT MGD score) for differentiating SGD from MGD with the use of preoperative parathyroid CT considers the size of only the largest candidate lesion. OBJECTIVE. The purpose of this study was to assess the utility of the size of the second-largest lesion on parathyroid CT for differentiating SGD from MGD as well as the utility of individual gland size for predicting the need for surgical removal and to derive optimal size thresholds for these purposes. METHODS. This retrospective study included patients with PHPT who underwent biochemically successful parathyroidectomy after preoperative parathyroid CT. Clinical radiology reports were reviewed to classify reported candidate parathyroid lesions as low-, intermediate-, or high-confidence lesions. Resected hypercellular parathyroid lesions were correlated with clinically reported candidate lesions. Patients were classified as having SGD or MGD on the basis of operative and pathology reports, independent of CT findings. One observer retrospectively determined the estimated volume (0.52 × length × width × height) and maximum diameter of clinically reported high-confidence lesions, as well as the 4D-CT MGD scores from the examinations. Diagnostic performance was assessed. RESULTS. The sample comprised 62 patients (41 women, 21 men; median age, 65 years), 47 of whom had SGD and 15 of whom had MGD, with 151 candidate lesions, including 106 high-confidence lesions. Based on the second-largest high-confidence lesions, an estimated volume threshold of 60 mm3 or greater achieved 53% sensitivity and 96% specificity, whereas a maximum diameter threshold of 7 mm or greater achieved 67% sensitivity and 96% specificity for MGD; a 4D-CT MGD score of 3 or greater achieved 47% sensitivity and 68% specificity for MGD. For predicting the need to remove a gland for successful parathyroidectomy, an estimated volume threshold of 114 mm3 or greater achieved 84% sensitivity and 97% specificity, and a threshold of 55 mm3 or greater achieved 93% sensitivity and 87% specificity; a maximum diameter threshold of 7 mm or greater achieved 93% sensitivity and 84% specificity. CONCLUSION. The estimated volume and maximum diameter of high-confidence candidate lesions can differentiate SGD from MGD and identify individual glands requiring removal for successful parathyroidectomy. Differentiating SGD from MGD may be aided by considering both the first- and second-largest high-confidence lesions. CLINICAL IMPACT. The findings will help identify patients who are likely to require bilateral neck explorations, informing preoperative patient counseling and individualized operative planning.

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

CONTEXT

Preoperative localization studies are standard practice in patients undergoing parathyroidectomy for primary hyperparathyroidism (pHPT). The most common modalities are neck ultrasound (US) and sestamibi scanning. However, the nature of pHPT is changing, with imaging increasingly yielding negative results. Numerous studies suggest unlocalized disease is associated with poor outcomes, calling into question whether such patients are best treated conservatively.

OBJECTIVE

This study aims to correlate parathyroidectomy outcomes with preoperative imaging in a single, high-volume institution.

METHODS

Data from a prospectively maintained departmental database of operations performed from 2017 to 2019 were analyzed. All patients undergoing first-time surgery for sporadic pHPT were included. Data collected included patient demographics, preoperative imaging, surgical strategy, and postoperative outcomes.

RESULTS

A total of 609 consecutive parathyroidectomies were included, with a median age of 59 years (range 20-87 years). The all-comer cure rate was 97.5%; this was 97.9% in dual localized patients (those with positive US and sestamibi), compared to 95.8% in the dual unlocalized group (those with negative US and sestamibi) (P = 0.33). Unilateral neck exploration was the chosen approach in 59.9% of patients with double-positive imaging and 5.7% of patients with double-negative imaging (otherwise, bilateral parathyroid visualization was performed). There was no significant difference in postoperative complications between patients undergoing unilateral or bilateral neck exploration.

CONCLUSIONS

Patients with negative preoperative imaging who undergo parathyroidectomy are cured in almost 96% of cases, compared to 98% when the disease is localized. This difference does not reach statistical or clinical significance. These findings therefore support current recommendations that all patients with pHPT who are likely to benefit from operative intervention should be considered for parathyroidectomy, irrespective of preoperative imaging findings.

Questionable value of [99mTc]-sestamibi scintigraphy in patients with pHPT and negative ultrasound

PURPOSE

A successful focused surgical approach in primary hyperparathyroidism (pHPT) relies on accurate preoperative localization of the parathyroid adenoma (PA). Most often, ultrasound is followed by [^99mTc]-sestamibi scintigraphy, but the value of this approach is disputed. Here, we evaluated the diagnostic approach in patients with surgically treated pHPT in our center with the aim to further refine preoperative diagnostic procedures.

METHODS

A single-center retrospective analysis of patients with pHPT from 01/2005 to 08/2021 was carried out followed by evaluation of the preoperative imaging modalities to localize PA. The localization of the PA had to be confirmed intraoperatively by the fresh frozen section and significant dropping of the intraoperative parathyroid hormone (PTH) levels.

RESULTS

From 658 patients diagnosed with pHPT, 30 patients were excluded from the analysis because of surgery for recurrent or persistent disease. Median age of patients was 58.0 (13-93) years and 71% were female. Neck ultrasound was carried out in 91.7% and localized a PA in 76.6%. In 23.4% (135/576) of the patients, preoperative neck ultrasound did not detect a PA. In this group, [^99mTc]-sestamibi correctly identified PA in only 25.4% of patients. In contrast, in the same cohort, the use of [¹¹C]-methionine or [¹¹C]-choline PET resulted in the correct identification of PA in 79.4% of patients (OR 13.23; 95% CI 5.24-33.56).

CONCLUSION

[¹¹C]-Methionine or [¹¹C]-choline PET/CT are superior second-line imaging methods to select patients for a focused surgical approach when previous ultrasound failed to identify PA.

Imaging of Treated Thyroid and Parathyroid Disease

The thyroid and parathyroid glands are endocrine structures located in the visceral space of the infrahyoid neck. Imaging plays a critical role in the evaluation of patients with thyroid cancer, both in the pre and posttreatment setting. Disorders of thyroid function, that is, hyperthyroidism and hypothyroidism, are also fairly common, although imaging utilization is less frequent with these conditions. Parathyroid dysfunction results in disordered calcium metabolism. Imaging is frequently applied in the preoperative assessment of these patients undergoing parathyroidectomy; however, routine imaging in the postoperative setting is uncommon. Parathyroid carcinoma is rare; however, imaging may be used in the pre and posttreatment setting.

DOSIMETRIC EVALUATION OF THE TWO-PHASE COMPUTED TOMOGRAPHY IN PARATHYROID GLANDS IMAGING

This study evaluates the patient radiation dose from the two-phase protocols of two different computed tomography (CT) systems and compares this with that delivered by the other similar protocols previously published. Two hundred and fourteen patients with primary hyperparathyroidism were included in the study with a two-phase CT scan between 2008 and 2020 by using a Toshiba Aquilion Prime 80 and a GE Light Speed 16. The standard 'neck' or a modified 'parathyroid' protocol was used. The patient dose was evaluated in terms of volumetric computed tomography dose index (CTDIvol), dose length product (DLP) and effective dose (ED) per acquisition protocol and CT system. CTDIvol and DLP were recorded retrospectively, while the ED was calculated based on DLP and an appropriate conversion coefficient. Comparisons of patient dose between the two protocols and two CT systems and the corresponding published values were established. A significantly lower patient dose (40.2-43.2%) than the GE system (p < 0.0001) resulted from the Toshiba system. The 'parathyroid' protocol resulted in a 6.5-9.6% lower patient dose than the standard 'neck' protocol. Compared with the literature, the lowest ED value (3.6 mSv) was observed since this protocol consists of a lowered tube voltage of 100 kVp, a reduced scan length for the pre-contrast phase and implementation of an iterative reconstruction algorithm.

Dual-Energy Parathyroid 4D-CT: Improved Discrimination of Parathyroid Lesions from Thyroid Tissue Using Noncontrast 40-keV Virtual Monoenergetic Images

BACKGROUND AND PURPOSE

In parathyroid CT, a noncontrast phase aids discrimination of parathyroid lesions (not iodine-containing) from thyroid tissue (iodine-containing). When thyroid iodine is pathologically diminished, this differentiation is difficult with standard CT. Because the attenuation of an element is maximal near its K-edge (iodine  = 33.2 keV), we hypothesized that dual-energy CT 40-keV virtual monoenergetic images will accentuate thyroid iodine relative to standard images, improving the differentiation of thyroid from parathyroid lesions. Our purpose was to test this hypothesis through quantitative assessment of Hounsfield unit attenuation and contrast-to-noise on dual-energy CT standard (70-keV) and 40-keV noncontrast images.

MATERIALS AND METHODS

For this retrospective study including 20 dual-energy parathyroid CTs, we used an ROI-based analysis to assess the attenuation of thyroid tissue, parathyroid lesions, and sternocleidomastoid muscle as well as corresponding contrast-to-noise on standard and 40- keV noncontrast images. Wilcoxon signed rank tests were performed to compare differences between 70  and 40 keV.

RESULTS

Absolute and percentage increases in attenuation at 40 keV were significantly greater for thyroid gland than for parathyroid lesions and sternocleidomastoid muscle (P < .001 for all). Significant increases in the contrast-to-noise of thyroid relative to parathyroid lesions (median increase, 0.8; P < .001) and relative to sternocleidomastoid muscle (median increase, 1.3; P < .001) were observed at 40 keV relative to 70 keV.

CONCLUSIONS

Forty-kiloelectron volt virtual monoenergetic images facilitate discrimination of parathyroid lesions from thyroid tissue by significantly increasing thyroid attenuation and associated contrast-to-noise. These findings are particularly relevant for parathyroid lesions that exhibit isoattenuation to the thyroid on parathyroid CT arterial and venous phases and could, therefore, be missed without the noncontrast phase.

Head-to-head comparison among 18F-choline PET/CT, 4D contrast-enhanced CT, and 18F-choline PET/4D contrast-enhanced CT in the detection of hyperfunctioning parathyroid glands: a systematic review and meta-analysis

INTRODUCTION

In primary hyperparathyroidism (PHPT), the localization of hyperfunctioning parathyroid gland (HPTG) allows tailored surgery. Although Four-Dimensional Contrast-enhanced Computed Tomography (4DCeCT) and ¹⁸F-choline Positron Emission Tomography/Computed Tomography (PET/CT) are reported to be promising second-line imaging procedures, no meta-analysis of their comparison exists.

DESIGN

we conducted a systematic review and meta-analysis to find original papers reporting the head-to-head comparison of 4DCeCT, ¹⁸F-choline PET/CT and integrated ¹⁸F-choline-PET/4DCeCT.

METHODS

this systematic review was conducted according to PRISMA. PubMed, CENTRAL, Scopus, and Web of Science were searched until January 2021. Studies comparing the ability of 4DCeCT, ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT to identify HPTG in patients with PHPT were selected. A per patient-based analysis of the three procedures was conducted in all patients (detection rate, DR) and in those with histologically confirmed HPTG (sensitivity).

RESULTS

Of the 78 records identified, five articles (153 PHPT patients) published between January the 1st, 2018 and January the 31st, 2021 were included. The pooled DR of ¹⁸F-choline PET/CT, 4DCeCT and ¹⁸F-choline PET/4DCeCT was 0.86, 0.69, and 0.86, respectively, while their pooled sensitivity was 0.89, 0.77 and 0.93, respectively. The analysis of pooled discrepancy showed that the sensitivity of ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT was higher than that of 4DCeCT by 0.11 and 0.13, respectively, the sensitivity of ¹⁸F-choline PET/4DCeCT being 0.06 higher than that of ¹⁸F-Choline PET/CT.

CONCLUSIONS

This meta-analysis suggests that the sensitivity of ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT is higher than that of 4DCeCT, while only a slight difference was observed between ¹⁸F-choline PET/CT and ¹⁸F-choline PET/4DCeCT.

Sestamibi Single-Positron Emission Computed Tomography/Diagnostic-quality Computed Tomography for the localization of abnormal parathyroid glands in patients with primary hyperparathyroidism: What clinicopathologic factors affect its accuracy?

PURPOSE

Sestamibi Single-Positron Emission Computed Tomography/Diagnostic-quality Computed Tomography (MIBI-SPECT/CT) is a common technology used for primary hyperparathyroidism (PHPT) localization in clinical practice. However, the clinicopathologic factors affecting the accuracy of MIBI-SPECT/CT and the potential limitations remain unclear.

METHODS

Retrospectively enrolled PHPT patients (n = 280) were analyzed from August 2017 to December 2019.

RESULTS

Of 96 patients with PHPT (mean age, 54 years; 63 females), 17 had discordance between MIBI-SPECT/CT and intraoperative findings. Among the 17 patients with discordance, 58.8% had major discordance, which occurred in most patients with multigland disease (MGD). Compared with concordant patients, discordant patients exhibited increased frequencies of autoimmune thyroid disease (29.4% vs 10.1%, p = 0.035), MDG (41.2% vs 3.8%, p = 0.035), higher PTH (296 pg/mL vs 146 pg/mL; p = 0.012),and lower phosphorus levels (0.77 mmol/L vs 0.90 mmol/L; p = 0.024). MDG (odds ratio [OR], 16.95; 95% CI 2.10-142.86), parathyroid lesion size of 12 mm or less (OR, 6.93; 95% CI 1.41-34.10), and a PTH level higher than 192.5 pg/mL (OR, 12.66; 95% CI 2.17-71.43) were independently associated with discordant MIBI-SPECT/CT results.

CONCLUSION

MGD was most strongly associated with discordance between MIBI-SPECT/CT and intraoperative findings followed by a PTH level higher than 192.5 pg/mL and parathyroid lesion size of 12 mm or less. Surgeons should recognize these potential limitations, which may improve the preoperative procedure by encouraging further localization imaging and promptly facilitate intraoperative troubleshooting.

Surgical outcome after focused parathyroidectomy: experience from a tertiary care centre in North India

&lt;b style=&quot;color: #075541&quot;&gt; Introduction:&lt;/b&gt; Focused parathyroidectomy is the gold standard treatment for primary hyperparathyroidism (PHPT) due to single gland disease with a comparable success rate as that of conventional four gland exploration. It is also associated with fewer surgical complications. Despite these benefits, there is still controversy about the high recurrence following the focused approach. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Aim:&lt;/b&gt; The aim was to analyse our experience regarding the success rate of focused parathyroidectomy for PHPT. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Methods:&lt;/b&gt; This was a retrospective analysis of 192 patients of PHPT between January 2017 and August 2020 who underwent focused parathyroidectomy without intraoperative parathormone analysis, and had a minimum follow up of six months. Demographic profile, biochemical (pre and postoperative), radiological, operative and histological detail of all patients were recorded. Parathyroidectomy was considered curative if the patient maintained normal serum calcium and parathormone (PTH) levels six months after surgery. Persistent hyperparathyroidism was considered if hypercalcemia or high PTH levels persisted, or recurrent disease when a patient had rising serum calcium and / or PTH levels six months after curative parathyroidectomy. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Results:&lt;/b&gt; No patient had pain and wound-related complications after parathyroidectomy. Two patients had voice change in the immediate postoperative period which recovered subsequently; no patient had documented vocal cord paralysis. The persistent disease was present in two patients; both required neck exploration. Five patients had recurrence of PHPT within six months of parathyroidectomy; all of them had hyperplasia on the final biopsy. The overall cure rate was 97.92%. &lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;Conclusion:&lt;/b&gt; Therefore, we propose focused surgery for sporadic PHPT should be considered as a preferred treatment with acceptable recurrence rate and surgical complications.&lt;/br&gt; &lt;/br&gt; &lt;b style=&quot;color: #075541&quot;&gt;KEYWORDS:&lt;/b&gt;focused parathyroidectomy, parathyroidectomy, primary hyperparathyroidism.

Differences in Primary Hyperparathyroidism Between Pre- and Postmenopausal Women in India

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a common endocrine disorder in women which becomes more prevalent after menopause. In this study, we compared the demographic, clinical, and biochemical variables between premenopausal (pre-M) and postmenopausal (post-M) women with PHPT.

METHODS

A retrospective analysis (from 2005 to 2019) of enrolled women PHPT patients from an online Indian PHPT registry.

RESULTS

Of the women with PHPT, 232 and 122 were pre-M and post-M, respectively. The number of post-M PHPT cases registered had a 3.3-fold increase in 2015-2019 from 2005-2009 compared with only a 2.5-fold increase in pre-M cases in the same duration. The majority were symptomatic (90%), although pre-M had a higher proportion of symptomatic than post-M (92% vs 85%; P = .04). Pre-M women showed more prevalence of osteitis fibrosa cystica than post-M women (28% vs 13%; P = .03), although hypertension and gallstone disease were seen more frequently in post-M PHPT women. Pre-M women had a significantly higher median PTH (403 vs 246 pg/mL; P = .02) and median alkaline phosphatase (202 vs 145 pg/mL; P = .02) than post-M women, and vitamin D deficiency was more common in pre-M women (58% vs 45%; P = .03). Gland localization, tumor weight, and disease cure rates did not differ according to menopausal status.

CONCLUSION

PHPT was more prevalent in pre-M women, although the number of post-M cases had significantly increased in the last 10 years. Pre-M women had generally more severe clinical and biochemical variables than post-M PHPT women.

Ultrasound combined with biochemical parameters can be used to differentiate parathyroid carcinoma from benign tumors in patients with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT) results from excessive secretion of parathyroid hormone from parathyroid tumors. Differentiating parathyroid tumors can be challenging before operation.

OBJECTIVES

To differentiate parathyroid carcinoma from benign tumors in patients with PHPT by the application of ultrasound and biochemical parameters.

METHODS

This study is a retrospective study. The study enrolled 17 patients with parathyroid carcinoma (PC) and 57 patients with parathyroid adenoma (PA), confirmed by postoperative pathology, between September 2010 and July 2017. This study retrospectively compared the ultrasonic features of the tumors included echotexture, maximum lesion diameter, shape, margin, blood flow inside the mass, intralesional calcifications, cysts in the mass, and biochemical parameters included serum calcium, phosphorus, parathyroid hormone (PTH), alkaline phosphatase (ALP) levels, gender distribution and age of patients between patients with PC and those with PA.

RESULTS

In the US images, the two groups showed significant differences in heterogeneity, the appearance of a taller-than-wide shape, irregular or lobulated margins, and intralesional calcifications (p < #x003C;< #x200A;0.05). However, no significant difference was found in echogenicity, maximum lesion diameter, blood flow, and cystic components of the mass (p > #x003E;> #x200A;0.05). The mean PTH levels were significantly different between the two groups (p < #x003C;< #x200A;0.05). The PC and PA patients did not differ significantly in terms of mean serum calcium, mean serum phosphorus, and mean ALP levels (p > #x003E;> #x200A;0.05). There were significant differences to distinguish PC from PA in calcifications in mass or/and taller-than-wide shape combine with PTH > #x003E;> #x200A;1000 pg/mL (p < #x003C;< #x200A;0.05). Significant difference existed in the age between the two groups (p < #x003C;< #x200A;0.001). No significant difference existed in the gender distribution between the two groups (p > #x003E;> #x200A;0.05).

CONCLUSION

Ultrasound features especially intralesional calcifications and taller-than-wide shape combine with an extremely high serum PTH (>1000 pg/mL) are helpful in differentiating between benign and parathyroid tumors in patients with PHPT.

Will 18F-fluorocholine PET/CT replace other methods of preoperative parathyroid imaging?

INTRODUCTION

Primary hyperparathyroidism (PHPT) is a common endocrine disorder usually due to hyperfunctioning parathyroid glands (HPs). Surgical removal of the HPs is the main treatment for PHPT, making the correct detection and localization of HPs crucial to guiding targeted and minimally invasive surgical treatment in patients with PHPT. To date, different imaging methods have been used to detect and localize HPs, including radiology, nuclear medicine, and hybrid techniques.

METHODS

The present work discusses the role and value of different imaging methods in PHPT and, particularly, evaluates the potential role of ¹⁸F-fluorcholine PET/CT as a "one-stop-shop" method for preoperative parathyroid localization in patients with PHPT.

DISCUSSION

Cervical ultrasound (US) and parathyroid scintigraphy using ^99mTc-MIBI are the most commonly employed methods in clinical practice. More recently, four-dimensional computed tomography (4D CT) and positron emission tomography (PET) with radiolabeled choline have emerged as useful alternatives in cases of negative or discordant findings from first-line imaging methods.

CONCLUSIONS

Due to the excellent diagnostic performance of radiolabeled choline PET/CT and the low radiation burden, this technique seems to be an ideal candidate to substitute current imaging procedures including US, MIBI scintigraphy, 4D CT and MRI and perform a fast and reliable "one-stop-shop" preoperative localization of HP in patients with PHPT, including challenging cases of postoperative persistent/recurrent disease.

Inactivation of parathyroid hormone: perspectives of drug discovery to combating hyperparathyroidism

Hormonal coordination is tightly regulated within the human body and thus regulates human physiology. The parathyroid hormone (PTH), a member of the endocrine system, regulates the calcium and phosphate level within the human body. Under non-physiological conditions, PTH levels get upregulated (hyperparathyroidism) or downregulated (hypoparathyroidism) due to external or internal factors. In the case of hyperparathyroidism, elevated PTH stimulates cellular receptors present in the bones, kidneys, and intestines to increase the blood calcium level, leading to calcium deposition. This eventually causes various symptoms including kidney stones. Currently, there is no known medication that directly targets PTH in order to suppress its function. Therefore, it is of great interest to find novel small molecules or any other means that can modulate PTH function. The molecular signaling of PTH starts by binding of its N-terminus to the G-protein coupled PTH1/2 receptor. Therefore, any intervention that affects the N-terminus of PTH could be a lead candidate for treating hyperparathyroidism. As a proof-of-concept, there are various possibilities to inhibit molecular PTH function by (i) a small molecule, (ii) N-terminal PTH phosphorylation, (iii) fibril formation and (iv) residue-specific mutations. These modifications put PTH into an inactive state, which will be discussed in detail in this review article. We anticipate that exploring small molecules or other means that affect the N-terminus of PTH could be lead candidates in combating hyperparathyroidism.

Minimally invasive video-assisted thyroidectomy and transoral video-assisted thyroidectomy: A comparison of two systematic reviews

Background:

We compared two systematic reviews, one focusing on transoral video-assisted thyroidectomy (TOVAT) and the other on minimally invasive video-assisted thyroidectomy (MIVAT), to highlight the pros and cons that can determine the choice of one or the other procedure.

Materials and Methods:

PubMed, Scopus and ISI Web of Science databases were searched for relevant articles published from 2000 to June 2018. Both searches were performed using the same keywords. All articles describing human surgical case series of any size were included, while the following were excluded: articles published in languages other than English, case reports, reviews, early cadaver and animal studies and old reports of cases now included in more recent works. Application of the above selection criteria yielded 151 articles on TOVAT and 246 on MIVAT. Of these, 34 articles were selected for inclusion in the present study: 17 for the TOVAT group and 17 for the MIVAT group. The comparison was made considering the most common variables used in evaluating thyroid surgery procedures. The statistical methods used were Cohen's delta, Student's t-test and the non-parametric Mann–Whitney U-test.

Results:

The variable 'operative time' was found to show a very large effect size, and 'hospital stay' also differed significantly between the MIVAT and TOVAT groups.

Conclusions:

TOVAT and MIVAT should not be considered in competition with each other, but seen simply as alternative choices. Both appear to be safe methods, comparable in terms of post-operative complications, although the main reason for using TOVAT seems to be purely aesthetic.

Parathyroid 4D CT: What the Surgeon Wants to Know

Parathyroid four-dimensional (4D) CT is an increasingly used and powerful tool for preoperative localization of abnormal parathyroid tissue in the setting of primary hyperparathyroidism. Accurate and precise localization of a single adenoma facilitates minimally invasive parathyroidectomy, and localization of multiglandular disease aids bilateral neck exploration. However, many radiologists find the interpretation of these examinations to be an intimidating challenge. The authors review parathyroid 4D CT findings of typical and atypical parathyroid lesions and provide illustrative examples. Relevant anatomy, embryology, and operative considerations with which the radiologist should be familiar to provide clinically useful image interpretations are also discussed. The most important 4D CT information to the surgeon includes the number, size, and specific location of candidate parathyroid lesions with respect to relevant surgical landmarks; the radiologist's opinion and confidence level regarding what each candidate lesion represents; and the presence or absence of ectopic or supernumerary parathyroid tissue, concurrent thyroid pathologic conditions, and arterial anomalies associated with a nonrecurrent laryngeal nerve. The authors provide the radiologist with an accessible and practical approach to performing and interpreting parathyroid 4D CT images, detail what the surgeon really wants to know from the radiologist and why, and provide an accompanying structured report outlining the key information to be addressed. By accurately reporting and concisely addressing the key information the surgeon desires from a parathyroid 4D CT examination, the radiologist substantially impacts patient care by enabling the surgeon to develop and execute the best possible operative plan for each patient. ^©RSNA, 2020.

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.

Incidental thyroid carcinomas. A retrospective study

AIM

The aim of the present study is to report our series of incidental thyroid carcinomas in the last 15 years and their follow-up, discussing therapeutics indications and surgical choices.

PATIENTS AND METHODS

We have considered 1793 patients operated on Surgical Sciences Department of "Sapienza" University of Rome from January 1, 2001 to December 31, 2015. The study was conducted on 83 totally thyroidectomized patients with a real incidental thyroid carcinoma, by clinical, laboratory and instrumental controls. Whole-body scan was the most important test in postoperative evaluation.

RESULTS

In our series, the incidence of incidental carcinomas was 4.62%. Compared to the total number of cancer patients, the percentage is 21,9%. In 15.66% of cases there was multifocality and in 7.23% also bilaterality. Regarding the histological type, in all cases they were papillary carcinoma. The size of the neoplastic lesions ranged from a minimum of 3 to a maximum of 10 mm. Whole-body scan revealed lymph node metastasis in 57.69% of patients.

DISCUSSION

Comparing these data with our previous studies we have seen a significant increase in incidence of incidental thyroid carcinomas over the years. Our therapeutical choice is total thyroidectomy and complection thyroidectomy after lobectomy, because of a relevant percentage of multifocality and/or bilaterality of these tumors. Many Authors on the contrary prefer a more conservative approach invoking the good prognosis of these tumors. The 57.69% of lymph node metastasis at postoperative whole-body scan comfort us in our setting.

CONCLUSION

Incidental thyroid carcinomas are not uncommon. We consider only tumors until 1 cm in diameter. Multifocality and bilaterality are often present such as occult lymph node metastasis. Our therapeutical choice is total thyroidectomy in order to conduct a proper follow-up.

Intraoperative parathyroid hormone (PTH) testing in patients with primary hyperparathyroidism and PTH levels in the normal range

Background

Primary hyperparathyroidism is a common endocrine disorder. Hypercalcemia with normal PTH levels is very unusual and can lead to diagnostic difficulties. There are very few very few studies in the literature and all with limited numerical samples. The goal of the present study was to determine the real incidence and characteristics of primary hyperparathyroidism with normal PTH and to evaluate if intraoperative PTH testing is useful in these patients.

Methods

We performed a retrospective review of 314 patients who had undergone parathyroidectomy to treat primary hyperparathyroidism between January 2002 and December 2016. Patients were divided in two groups according to biochemical preoperative findings: in Group A were included patients with normal serum PTH, in Group B those with increased serum PTH.

Results

Nine patients (3.7%) were included in group A and 235 in group B. Patients in group A were younger (51.5 ± 12.9 years vs 59.6 ± 12.5); preoperative serum calcium and the incidence of coexisting thyroid disease were similar between the two groups. Symptomatic patients were more frequent in Group A (77.8% vs 39.1%; p = 0.048). There were no significant differences regarding preoperative localization studies and surgical procedure. Intraoperative PTH determination demonstrated sensitivity of 86% in group A and 97% in group B, specificity and positive predictive value of 100% in both the groups, negative predictive value of 67% in group A and 79% in group B. Histopathological examination demonstrated a single gland disease in 8 (88.9%) patients in group A and a multi gland disease in 1 (11.1%), in group B single gland disease was found in 218 (92.8%) patients and multi gland disease in 17 (7.2%). Unsuccessful surgery with persistent or recurrent hyperparathyroidism occurred in 1 (11.1%) patient in group A and 4 (1.7%) in group B.

Conclusions

Primary hyperparathyroidism with normal PTH is rare but physicians should be aware of this possibility in patients with hypercalcaemia. Patients with normal PTH levels are younger and more frequently symptomatic. Intraoperative PTH testing plays an important role in the operative management even in such patients.

Importance of Parathyroid Hormone Needle Aspiration Washout in Adenoma Localization in Primary Hyperparathyroidism

Background

Primary hyperparathyroidism is an endocrine disease characterized by excessive secretion of parathyroid hormone and hypercalcemia. Although scintigraphy is commonly used for pre-operative localization, it does not always localize the parathyroid lesion. In such patients, ultrasonography can visualize the suspected lesion and needle washout sample for parathyroid hormone titer can be used to confirm parathyroid tissue. The aim of this study was to investigate the accuracy of the parathyroid hormone needle aspiration washout method in detecting the localization of parathyroid adenoma.

Material/Methods

Patients with primary hyperparathyroidism who underwent surgery between 2010 and 2017 at the Dicle University Medical Faculty Hospital were retrospectively evaluated using medical records. Patients undergoing parathyroid hormone needle aspiration washout were performed in the suspected lesion were included in the study. Accompanied by ultrasonography, the suspected area was penetrated with needle, and negative aspiration was performed. Pre-operative scintigraphic data of patients were evaluated. Patients with positive scintigraphy, negative scintigraphy or patients who did not undergo scintigraphy were included in our study. Demographic data were presented as continuous data means ± standard deviation. Categorical variables were presented as frequency and percentage.

Results

Forty-nine patients (female/male, 40/9) who underwent parathyroid hormone needle aspiration washout were included in the study. Parathyroid hormone washout result was positive in 47 patients (47/49) and negative in 2 patients (2/49), sensitivity/positive predictive value (PPV) 95.91%. Twenty-six patients who had negative/suspicious scintigraphic results were diagnosed using the parathyroid hormone needle aspiration washout method (24/26, 92.3% accuracy). Parathyroid hormone needle aspiration washout without scintigraphy was performed in 13 patients (13/13, 100% accuracy).

Conclusions

Parathyroid adenoma localization can be easily done using parathyroid hormone needle aspiration washout in centers experienced in adenoma localization in primary hyperparathyroidism cases in which scintigraphic results are negative or scintigraphy cannot be performed. We believe that primary parathyroid hormone needle aspiration washout can be a new localization method for adenoma localization.

[Current approach to the diagnosis and treatment of primary hyperparathyroidism]

AIM

To optimize diagnosis and surgical treatment of patients with primary hyperparathyroidism.

MATERIAL AND METHODS

Retrospective comparative analysis of diagnosis and surgical treatment included 444 patients who were treated at the specialized department of endocrine surgery of Pirogov National Medical Surgical Center in 2012-2017. Archival materials and electronic databases of the clinic were applied.

RESULTS

It was developed the algorithm which may be used in most patients for minimally invasive parathyroidectomy. Minimally invasive surgery reduces the risk of complications and is associated with reliable efficacy and good cosmetic effect.

Correlation of surgeon-performed parathyroid ultrasound with the Perrier classification and gland weight

BACKGROUND

Ultrasound localisation of parathyroid glands correlates with gland weight. We hypothesise that gland identification is also dependent on anatomical location. Perrier et al. have described a uniform and reliable nomenclature for parathyroid locations. We aimed to correlate surgeon-performed ultrasound (SUS) with intra-operative Perrier classification and gland weight.

METHODS

Review of a prospectively maintained single operator SUS database of 194 patients referred with non-familial primary hyperparathyroidism (PHPT) at a tertiary centre between 2010 and 2015. Patients underwent MIBI localisation as well as on table SUS. Intra-operative pathological gland locations were classified according to the Perrier nomenclature.

RESULTS

Mean weight of pathological glands found and missed by SUS was 1.07 ± 0.1 g and 0.48 ± 0.08 g respectively (p = 0.0001, unpaired t test). The weight of glands identified was greater than that of missed glands for each of the Perrier locations (p < 0.001, Mann-Whitney). The proportion of pathological glands found at each Perrier location varied significantly (p < 0.0001, Chi Square); so we find proportionally more B-, D-, E- and F-type glands and miss more A- and C-type glands. The median weight of glands missed on SUS varied significantly across the Perrier groups (Kruskal-Wallis, p = 0.0034) and suggests that SUS can miss quite large glands (> 0.5 g) in locations B, C and F; whereas missed glands in locations A, D and E were all small (< 0.5 g).

CONCLUSION

Whilst gland identification correlates well with gland weight, anatomical location has a significant impact on failure of localisation irrespective of gland weight. For the surgeon operating on PHPT patients with negative US localisation, particular attention should be paid to locations C, D and A as these are the sites where pathological glands are most often missed on pre-operative US.

MIBI scintigraphy of parathyroid adenomas: correlation with biochemical and histological markers

PURPOSE

In this study, we tested the hypothesis that MIBI-positive and MIBI-negative adenomas of parathyroid glands (APGs) have distinct biochemical and histological markers that could help differentiate MIBI-positive from MIBI-negative APGs.

PATIENTS AND METHODS

40 patients with 41 APGs were included in the study. Patients were enrolled in the study after MIBI scintigraphy examinations had been carried out. Biochemical analyses included serum levels of calcium (Ca), intact parathyroid hormone (iPTH), and 25-hydroxyvitamin D3 (25-OH-D3). All patients had neck ultrasound and MIBI examinations. After surgical resection the APGs were examined histologically.

RESULTS

In each of 39 patients one APG could be confirmed by histology, and in one patient, two contralateral APGs were identified. MIBI studies were positive in 73 % and negative in 27 % of the APGs. False-positive cases were not observed. MIBI-negative APGs were only present in patients with iPTH values below 150 pg/ml. In 82 % of MIBI negative studies oxyphilic cells were absent, and this cell type was present in only 18 % of MIBI negative cases (p < 0.001). Regarding cysts within the APGs, no differences were demonstrated between MIBI positive or negative studies (p = 0.32). Fat cells were seen in none of the MIBI -negative studies and in only 3 % of MIBI positive studies (p = 0.08).

CONCLUSIONS

For APGs, MIBI positivity correlates with serum iPTH concentration. The absence of oxyphilic cells with large numbers of mitochondria in APGs contributes to MIBI negativity, probably because of the reduced binding sites for the radiotracer.

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.

A Novel Technology for Localization of Parathyroid Adenoma: Ultrasound-Guided Fine Needle Aspiration Combined With Rapid Parathyroid Hormone Detection and Nano-Carbon Technology

Objective. The study aims to evaluate the clinic feasibility of rapid parathyroid hormone (PTH) detection and nano-carbon technology in preoperative diagnosis and localization of parathyroid adenoma. Methods. With the guidance of ultrasound, the operator performed the parathyroid puncture and tested the PTH value by using a PTH test kit, and then injected nano-carbon into parathyroid adenoma as a marker to observe whether the parathyroid adenoma was stained black during the final operation. Meanwhile, a part of excised specimen was made into homogenate and detected rapidly again by using the PTH test kit. The remaining was confirmed by intraoperative frozen pathological examination. Result. The sensitivity (12/12) of preoperative diagnosis was significantly higher than that of ultrasound (6/12), magnetic resonance imaging (7/12), and MIBI (9/12). During the operation, we found that the inner part of the parathyroid adenoma was stained black, and the PTH value of the specimen homogenate confirmed as parathyroid adenoma was more than 3000 pg/mL. Conclusion. This novel technology, as a very positive method for localization of parathyroid adenoma, plays an important role in guaranteeing the surgical reliability of parathyroid adenoma with help of nano-carbon technology.

Comparison of scintigraphy and ultrasound imaging in patients with primary, secondary and tertiary hyperparathyroidism - own experience

BACKGROUND

The imaging techniques most commonly used in the diagnosis of hyperparathyroidisms are ultrasound and scintigraphy. The diagnostic algorithms vary, depending mainly on the population, and experience of physicians.

AIM

Aim of the present research was to determine the usefulness of parathyroid scintigraphy and ultrasonography in patients diagnosed for hyperparathyroidism in own material.

MATERIAL AND METHOD

In the present research, 96 operated patients with documented primary, secondary and tertiary hyperparathyroidism were retrospectively analyzed. All patients underwent a ^99mTc hexakis-2-methoxyisobutylisonitrile scintigraphy of the neck with the use of subtraction and two-phase examinations. Ultrasonography of the neck was performed in all the patients in B mode 2D presentation. A total number of 172 parathyroid glands were analyzed.

RESULTS

The sensitivity and specificity of scintigraphy was 68% and 60%, respectively. The sensitivity of ultrasound was 49% and specificity 85%. Both techniques allowed visualization of 76 parathyroid glands. Ultrasound revealed 19 glands that were not visible in scintigraphy. Scintigraphy showed 76 parathyroid glands that were not visualized on ultrasound. Having combined the results of scintigraphy and ultrasound, the sensitivity of 76% and specificity of 50% were obtained. Considering the ability to locate the parathyroid glands in both techniques as a positive result, the sensitivity decreased to 37% and specificity rose to 95%.

CONCLUSIONS

Scintigraphy showed greater sensitivity than ultrasound in the localization of enlarged parathyroid glands. Ultrasound, in turn, was characterized by a higher specificity. The combined use of scintigraphy and ultrasonography allowed to obtain the specificity of 95%. In the light of obtained results, scintigraphy and ultrasonography are complementary and should be used together.

An unusual mediastinal parathyroid carcinoma coproducing PTH and PTHrP: A case report

Parathyroid carcinoma (PTCA) is a rare disease, and ectopic PTCA is particularly rare. Parathyroid hormone-related protein (PTHrP) expression in PTCA has not been previously described in the relevant literature to the best of our knowledge. The present study reports a unique case with a mediastinal parathyroid carcinoma producing parathyroid hormone (PTH) and PTHrP. A 53-year-old man presented with hyperparathyroidism symptoms, including fatigue, chest pain, dizziness, muscular soreness, polyuria, night sweats and renal stones. However, neck ultrasound revealed no significantly abnormal thyroid or parathyroid nodules. Tc99m methoxyisobutylisonitrile (Tc99m-MIBI) scintigraphy scanning indicated an ectopic mediastinal parathyroid adenoma. Histopathological examination revealed PTCA, and the tumor tissue was coproducing PTH and PTHrP. The patient underwent successful surgical operation. Serum calcium and PTH levels remained within normal ranges, and there was no tumor recurrence observed at a 3-year follow-up appointment. Although rare, ectopic parathyroid glands may lead to malignant disease. Clinical symptoms, biochemical tests, ultrasound and Tc99m-MIBI scintigraphy scanning may assist with the diagnosis of this disease. Hypersecretion of PTHrP and PTH contributed collaboratively to the pathogenesis of hypercalcemia due to PTCA. Complete surgical resection with microscopically negative margins is the recommended treatment for PTCA and offers the best chance of a cure.

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.