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

The utility of intraoperative PTH dosage in primary hyperparathyroidism based on preoperative diagnosis and surgical choice

BACKGROUND

The aim of this study was to evaluate the impact of the intraoperative PTH (ioPTH) monitoring in the success of parathyroidectomy based on the concordant or indeterminate preoperative imaging studies of localization and the performed surgical choices.

METHODS

Fourthy-seven patients who received parathyroidectomy operations were divided in four groups: concordance of the imaging and ioPTH, concordance of the imaging and no ioPTH, indeterminate imaging and ioPTH and indeterminate imaging and no ioPTH.

RESULTS

Overall, patients in whom ioPTH monitoring was not performed were healed in 89.47% of cases, while the percentage of recovery in patients receiving ioPTH was 85.71%. There were no differences in the changes in strategy or in the cure rates with the use of ioPTH.

CONCLUSIONS

No significant differences were found, independently from the preoperative imaging agreement, in either the cure rate or in the change of intraoperative strategy using the ioPTH dosage.

Parathyroid disorder and concomitant thyroid cancer in patients with multiple endocrine neoplasia type 1: A retrospective cohort study

This study aimed to determine the rates and characteristics of parathyroid disorder and thyroid cancer in patients with multiple endocrine neoplasia type 1 vs sporadic primary hyperparathyroidism (SPHP) undergoing parathyroidectomy.Patients with multiple endocrine neoplasia type 1-associated primary hyperparathyroidism (MPHP) or SPHP who underwent initial or reoperative parathyroid exploration from 1999 to 2019 were identified via a clinical database. The data for MPHP patients (n = 15) were compared to those of a selected 2:1 age- and sex-matched SPHP cohort (n = 30) who all underwent thyroidectomy for concurrent thyroid nodules.Compared with that of the SPHP group, the parathyroid hormone level of the MPHP group was much higher (470.67 ± 490.74 pg/mL vs 217.77 ± 165.60 pg/mL, P = .001). Multiglandular parathyroid disease (6/15 [40%] vs 3/30 [10%], P = .026) and more hyperplasia (7/15 [46.7%] vs 5/30 [16.7%], P = .039) were found in the MPHP group, and more parathyroid lesions presented as a round shape (long/short meridian < 2) by ultrasound (16/20 [80%] vs 8/31 [25.8%], P < .001). Regarding thyroid nodules, there was no difference in the rate of histologic thyroid cancer, but more thyroid cancer was found in the last 5 years among the MPHP cases (5/9 [55.6%] vs 3/18 [16.7%], P = .052).Multiglandular parathyroid disease and hyperplasia were more frequent in the MPHP cohort than in the SPHP cohort, and the parathyroid lesions usually presented with a round shape on ultrasonography. More concurrent thyroid cancer was found in MPHP than SPHP patients over the previous 5 years.

The Value of Preoperative and Intraoperative Ultrasound in the Localization of Intrathyroidal Parathyroid Adenomas

AIM

Intrathyroidal parathyroid adenoma (IPA) is rare and may easily be mistaken for thyroid nodule in ultrasonography. The aim of this study was to investigate the characteristic features of IPA and explore the value of preoperative and intraoperative ultrasound in the diagnosis and localization of IPA.

METHODS

13 of 216 patients who were found to have intrathyroidal parathyroid lesions underwent parathyroidectomy in our hospital because of PHPT. According to the relationship between parathyroid adenoma and thyroid gland, parathyroid adenoma was divided into extra-thyroid type or intra-thyroid type (partial or complete) and the results were compared with surgical and histopathological reports as gold standard. The sonographic features of intrathyroidal parathyroid lesions were analyzed retrospectively.

RESULTS

A total of 12 intrathyroidal lesions showed profoundly hypoechoic solid nodules with well-defined border, abundant blood flow and polar feeding vessels originating from the superior or inferior thyroid artery (92.3%, 12/13). These nodules were finally confirmed as IPA (or IPAC) after surgery. Polar feeding vessel was not detected in one case of parathyroid hyperplasia confirmed by pathology (7.7%, 1/13). 12 cases were diagnosed and localized on ultrasonography before operation and 10 cases were localized on Tc-99m MIBI SPECT/CT.

CONCLUSIONS

The color Doppler ultrasound findings of IPA were confirmed as profoundly hypoechoic nodules with clear boundary and abundant internal blood flow. The presence of polar feeding vessels which originate from thyroid artery were identified as characteristic features of US for IPA. Preoperative and intraoperative ultrasound could be helpful in the localization and treatment of intrathyroidal parathyroid diseases.

Efficacy of ultrasonography and Tc-99m MIBI SPECT/CT in preoperative localization of parathyroid adenomas causing primary hyperthyroidism

Background

Primary hyperparathyroidism (PHPT) results from an excess of parathyroid hormone (PTH) produced from an overactive parathyroid gland. The study aimed to explore the sonographic features of parathyroid adenomas and assess the diagnostic performance of ultrasonography (US) and Tc-99m MIBI SPECT/CT for preoperative localization of parathyroid adenomas.

Methods

A total of 107 patients were enrolled in this retrospective study who had PHPT and underwent parathyroidectomy. Of the 107 patients, 97 performed US and Tc-99m MIBI SPECT/CT examinations for preoperative localization of parathyroid nodules. The sensitivity and accuracy of each modality were calculated.

Results

In this study, residual parathyroid sign and polar vascular sign were identified as characteristic US features of parathyroid adenomas. These manifestations were closely related to the size of the abnormal parathyroid lesions. Among the 108 parathyroid nodules from 97 patients with PHPT, the sensitivity and accuracy of US for locating the parathyroid nodules were significantly higher than those of Tc-99m MIBI SPECT/CT (93.0% vs. 63.0% and 88.0% vs. 63.0% respectively; ²=26.224, 18.227 respectively, P<0.001). The differences between US+Tc-99m MIBI SPECT/CT and Tc-99m MIBI SPECT/CT-alone were statistically significant (²=33.410, 21.587 respectively, P<0.001), yet there were no significant differences in the sensitivity or accuracy between US+Tc-99m MIBI SPECT/CT and US-alone (²=0.866, 0.187 respectively, P=0.352 and 0.665).

Conclusions

US shows significantly better sensitivity and accuracy for localization of parathyroid adenomas than Tc-99m MIBI SPECT/CT. However, US combined with Tc-99m MIBI SPECT/CT is of great clinical value in the preoperative localization of parathyroid nodules in patients with PHPT.

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.

Scintigraphy has the potential to replace thyroid stimulating hormone and ultrasonography in hyperthyroidism diagnosis

The value of thyroid scintigraphy in hyperthyroidism diagnosis has long been the subject of debate. Unresolved issue is whether scintigraphy should be performed routinely, selectively, or for all hyperthyroidism patients. So, this study is concerned with the evaluation of thyroid scintigraphy for identifying hyperthyroidism in comparison with thyroid stimulating hormone (TSH) and ultrasound. This is cross sectional study including convenient patients sample (n = 50, 15 males and 35 females) aged (20-50 years) with primary hyperthyroidism and were attending endocrine clinics at King Faisal Specialist Hospital and Research Centre. All patients performed clinical investigations (TSH, ultrasound and thyroid scintigraphy). Among these patients, 96%, 48/50, had positive findings for hyperthyroidism with thyroid SC (95% CI; 96.0-99.5%); 84%, 42/50, had positive findings for hyperthyroidism by US (95% CI; 70.9-92.8%); and 56%, 28/50, had positive findings for hyperthyroidism by TSH measurement (95% CI; 41.3.0-70.0%). There was very good agreement between scintigraphy diagnosis and ultrasonography (kappa score = 0.812 (P < 0.0001), 95% CI (0.77-0.85). In many cases, scintigraphy provides considerably more functioning and anatomic details than ultrasound. In conclusion, these findings bring forth practical aspects of thyroid scintigraphy utilization for hyperthyroidism. By combining functional and anatomical information in one step, scintigraphy provides non-invasive, simple, fast and cost effective hyperthyroidism diagnostic method and has the potential to replace TSH and ultrasonography in hyperthyroidism investigation.

Ultrasound elastography score and strain index in different parathyroid lesions

BACKGROUND

Despite significant improvement in imaging quality and advanced scientific knowledge, it may still sometimes be difficult to distinguish different parathyroid lesions. The aims of this prospective study were to evaluate parathyroid lesions with ultrasound elastography and to determine whether strain index can help to differentiate parathyroid lesions.

METHODS

Patients with biochemically confirmed hyperparathyroidism and localised parathyroid lesions in ultrasonography were included. All patients underwent B-mode US and USE examination. Ultrasound elastography scores and strain index of lesions were determined. Strain index was defined as the ratio of strain of the thyroid parenchyma to the strain of the parathyroid lesion.

RESULTS

Data of 245 lesions of 230 patients were analysed. Histopathologically, there were 202 (82.45%) parathyroid adenomas, 26 (10.61%) atypical parathyroid adenomas, and 17 (6.94%) cases of parathyroid hyperplasia. Median serum Ca was significantly higher in atypical parathyroid adenoma patients than parathyroid hyperplasia patients (P = 0.019) and median PTH was significantly higher in APA compared to PA patients (P < 0.001). In 221 (90.2%) of the parathyroid lesions, USE score was 1 or 2. The median SI of atypical parathyroid adenomas was significantly higher than parathyroid adenomas and hyperplasia lesions (1.5 (0.56-4.86), 1.01 (0.21-8.43) and 0.91 (0.26-2.02), respectively, P = 0.003).

CONCLUSION

Our study revealed that SI of parathyroid lesions as well as serum calcium, parathyroid hormone levels, and B-mode US features may help to predict the atypical parathyroid adenoma. Ultrasound elastography can be used to differentiate among parathyroid lesions and guide a surgical approach.

The diagnostic value of parathyroid hormone washout in primary hyperparathyroidism patients with negative or equivocal 99 m Tc-MIBI results

BACKGROUND AND OBJECTIVES

The accurate identification of hyper functioning parathyroid gland is needed for definitive surgical treatment in primary hyperparathyroidism. Ultrasonography and 99mTechnetium sestamibi scintigraphy are the two most used methods with varying sensitivities. This study aimed to assess the value of parathyroid hormone (PTH) assay in preoperative ultrasound guided fine needle aspiration (FNA)-PTH washout fluid to verify the correct localisation of lesions with negative or inconclusive scintigraphy results.

METHODS

We evaluated data of 28 lesions in 21 patients who underwent US-guided parathyroid fine-needle aspiration (FNA) with PTH washout, retrospectively. The PTH washout results and the reports of parathyroid surgery and imaging studies were reviewed.

RESULTS

Of operated 28 lesions 23 had positive and 5 had negative washout results. The median FNA-PTH washout was 2315.5 pg/ ml (min-max: 12.3-6978 pg/ ml). The calculated sensitivity of FNA-PTH washout was 85.7% and the specifity was 28.6%. The positive and negative predictive values were 78.3% and 40.0%, respectively.

CONCLUSIONS

FNA-PTH can be used to establish the nature of the lesion, discriminate parathyroid gland from thyroid lesions or cervical lymph nodes, improving the surgical outcomes. It can be used to localise parathyroid lesions preoperatively when negative or discordant ultrasound and scintigraphy findings are obtained.

2D-Shear Wave Elastography in the Evaluation of Parathyroid Lesions in Patients with Hyperparathyroidism

BACKGROUND AND AIMS

2D-shear wave elastography (2D-SWE) is a relatively new elastographic technique. The aim of the present study is to determine the values of the elasticity indexes (EI) measured by 2D-SWE in parathyroid benign lesions (adenomas or hyperplasia) and to establish if this investigation is helpful for the preoperative identification of the parathyroid adenoma.

MATERIAL AND METHODS

The study groups were represented by 22 patients with primary or tertiary hyperparathyroidism, diagnosed by specific tests, and 43 healthy controls, in whom the thyroid parenchyma was evaluated, in order to compare the EI of the thyroid tissue with those of the parathyroid lesions.

RESULTS

The mean EI measured by 2D-SWE in the parathyroid lesions was 10.2 ± 4.9 kPa, significantly lower than that of the normal thyroid parenchyma (19.5 ± 7.6 kPa; p = 0.007), indicating soft tissue. For a cutoff value of 12.5 kPa, the EI assessed by 2D-SWE had a sensitivity of 93% and a specificity of 86% (AUC = 0.949; p < 0.001) for predicting parathyroid lesions.

CONCLUSION

A value lower than 12.5 kPa for the mean EI measured by 2D-SWE can be used to confirm that the lesion/nodule is a parathyroid adenoma.

Impact of preoperative imaging on surgical approach for primary hyperparathyroidism: Data from single institution in India

CONTEXT

Preoperative localization of parathyroid adenoma is essential in deciding the surgical approach of parathyroidectomy.

AIM

To describe clinical and biochemical profile, evaluate preoperative imaging modalities and surgical approach in patients with primary hyperparathyroidism (PHPT).

METHODOLOGY

This was a retrospective study conducted at the single institution. All patients who underwent evaluation and surgery for PHPT from 2011 to 2015 were included in the study.

RESULTS

A total of 100 patients underwent surgery for PHPT. Mean (standard deviation) age was 51.6 (15.9) years with female to male ratio of 1.7:1. Forty patients had severe symptoms, and sixty had mild to moderate symptoms. The sensitivity of technetium-99m hexakis (2-methoxyisobutylisonitrile) (MIBI) scan and ultrasonography (USG) neck in identifying abnormal parathyroid gland was 93% (93/100) and 98% (98/100), respectively. The MIBI scan results of 90/93 (96.7%) patients corresponded with their surgical findings whereas preoperative USG findings of 96/98 patients (98%) showed correlation with operative findings. Intraoperative intact parathyroid hormone (IOPTH) levels at 10 min postexcision were measured in forty patients (minimally invasive parathyroidectomy = 38, bilateral neck exploration = 1, and unilateral neck exploration = 1). All patients except two had <50% fall in IOPTH. Adenoma weight was positively correlated with preoperative intact PTH.

CONCLUSION

We found that USG has higher sensitivity (98%) than MIBI scan (93%) in localizing abnormal parathyroid gland. Moreover, USG had a higher preoperative localization accuracy (93%) than MIBI scan (90%), allowing to choose an appropriate surgical approach. A higher proportion of patients (60%) had mild/asymptomatic form of PHPT.