Positive predictive values of ultrasound-guided fine-needle aspiration with parathyroid hormone assay and Tc-99m sestamibi scintigraphy in sporadic primary hyperparathyroidism

OBJECTIVES

Ultrasonography (US) and Tc-99m sestamibi scintigraphy (SS) are usually performed as preoperative imaging modalities for patients with sporadic primary hyperparathyroidism (SPHP). Fine-needle aspiration (FNA) under US guidance for parathyroid hormone (PH) assay can enhance the diagnostic accuracy of US. The main aim of the present study was to compare positive predictive values between US-FNA and SS. The secondary aim was to draw up a decision-tree for FNA and SS.

METHODS

The single-center retrospective study included patients with previously non-operated SPHP. They underwent US-guided FNA, PET-CT SS, and 18 F-choline scintigraphy if the first two methods were inconclusive. PH washout level was considered pathological when greater than the serum PH level. Postoperative histology data were correlated to imaging data.

RESULTS

In total, 117 patients were included, with a mean age of 64 years (range, 26-89 years). A single adenoma was identified on pathology in 101 patients (89%). FNA findings were pathologic for 64 patients (55%), with a mean PH level of 2,604ng/L [range, 585-9,074ng/L], higher than the serum level of 179ng/L [range, 60-1,000ng/L]. US-guided FNA showed sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of respectively 72%, 92%, 99% and 28%, compared to 89%, 42%, 93% and 32% for SS. The rate of error in locating the parathyroid gland was 8% for US-guided FNA versus 12% for SS. Comparison of the two methods showed better sensitivity for SS (P=0.0052) and better specificity for FNA (P=0.0143), with no significant difference in PPV or NPV. 18 F-choline scintigraphy detected the hyperfunctioning parathyroid in 11 out of the 15 patients.

CONCLUSION

PPV did not significantly differ between FNA and SS. US-guided FNA performed by an experienced operator could be a simple first-line method for more than 50% of patients with non-operated SPHP, with 99% PPV. In case of negative or doubtful FNA findings, SS can be performed in second line.

Retrospective analysis of the role of intra-operative parathyroid hormone monitoring during parathyroidectomy for primary hyperparathyroidism: a single center experience over 2 decades

PURPOSE

Role of intra-operative parathyroid hormone (IOPTH) monitoring during parathyroidectomy for primary hyperparathyroidism (PHPT) has long been debated. Our main goal was to investigate the cure rates of parathyroidectomy for primary hyperparathyroidism with and without IOPTH monitoring. Our secondary goal was to investigate if operating room time can be saved when IOPTH monitoring is not used.

METHODS

A retrospective analysis of patients who underwent parathyroidectomy for PHPT due to a single adenoma between 2004 and 2019 was performed. Cure rates and operating room time were compared.

RESULTS

423 patients were included. IOPTH was used in 248 patients (59%). Four patients were not cured, two from each group, with no significant difference between the groups (98.8% vs. 99.1%, p = 0.725). Surgery time was significantly longer in the IOPTH group, p < 0.001.

CONCLUSIONS

There is no advantage for using IOPTH during parathyroidectomy in suitable clinical settings. The procedure may be safely performed without IOPTH while achieving non-inferior success rates and reducing operative time.

Pre-operative imaging workup for surgical intervention in primary hyperparathyroidism: A tertiary referral center experience

PURPOSE

Preoperative imaging in patients with primary hyperparathyroidism provides important localization information, allowing the surgeon to perform a focused surgery. However there are no evidence-based guidelines suggesting which preoperative imaging should be used, resulting in a risk of excessive prescription of exams and waste of economic resources. The main purpose of this study was to describe our experience on the performance of various imaging techniques for the preoperative localization of abnormal parathyroid gland/s, with a focus on the sensitivity and specificity of each technique. Secondly, we carried out an analysis of the cost utility of each technique in order to determine the most clinical and cost-effective combination of localization studies.

MATERIALS AND METHODS

Records of 336 patients who underwent parathyroidectomy were retrospectively examined comparing imaging and intraoperative/histopathologic findings to evaluate the accuracy in parathyroid detection of each imaging technique. Costs were determined by regional health system reimbursement.

RESULTS

We found that the sensitivity of color Doppler US was significantly higher than SPECT (p 0,023), while the sensitivity of 4D-CT was significantly better than US (p 0,029) and SPECT (p 0,0002).

CONCLUSIONS

In experienced hands color Doppler US is a highly sensitive technique especially in patients with no thyroid diseases. In patients with concomitant thyroid pathology, the combination of US and 4D-CT represents a reliable localization technique.

American Head and Neck Society Endocrine Surgery Section update on parathyroid imaging for surgical candidates with primary hyperparathyroidism

Health care consumer organizations and insurance companies increasingly are scrutinizing value when considering reimbursement policies for medical interventions. Recently, members of several American Academy of Otolaryngology-Head & Neck Surgery (AAO-HNS) committees worked closely with one insurance company to refine reimbursement policies for preoperative localization imaging in patients undergoing surgery for primary hyperparathyroidism. This endeavor led to an AAO-HNS parathyroid imaging consensus statement (https://www.entnet.org/content/parathyroid-imaging). The American Head and Neck Society Endocrine Surgery Section gathered an expert panel of authors to delineate imaging options for preoperative evaluation of surgical candidates with primary hyperparathyroidism. We review herein the current literature for preoperative parathyroid localization imaging, with discussion of efficacy, cost, and overall value. We recommend that planar sestamibi imaging, single photon emission computed tomography (SPECT), SPECT/CT, CT neck/mediastinum with contrast, MRI, and four dimensional CT (4D-CT) may be used in conjunction with high-resolution neck ultrasound to preoperatively localize pathologic parathyroid glands. PubMed literature on parathyroid imaging was reviewed through February 1, 2019.

Solitary Parathyroid Adenoma Localization in Technetium Tc99m Sestamibi SPECT and Multiphase Multidetector 4D CT

BACKGROUND AND PURPOSE

Minimally invasive parathyroid surgery relies critically on image guidance, but data comparing the efficacy of various imaging modalities are scarce. Our aim was to perform a blinded comparison of the localizing capability of technetium Tc99m sestamibi SPECT, multiphase multidetector 4D CT, and the combination of these 2 modalities (technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT).

MATERIALS AND METHODS

We reviewed the records of 31 (6 men, 25 women; median age, 56 years) consecutive patients diagnosed with biochemically confirmed primary hyperparathyroidism between November 2009 and March 2010 who underwent preoperative technetium Tc99m sestamibi SPECT and multiphase multidetector 4D CT performed on the same scanner with pathologic confirmation by resection of a single parathyroid adenoma. Accuracy was determined separately for localization to the correct side and quadrant using surgical localization as the standard of reference.

RESULTS

Surgical resection identified 14 left and 17 right parathyroid adenomas and 2 left inferior, 12 left superior, 11 right inferior, and 6 right superior parathyroid adenomas. For left/right localization, technetium Tc99m sestamibi SPECT achieved an accuracy of 93.5% (29 of 31), multiphase multidetector 4D CT achieved 96.8% accuracy (30 of 31), and technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT achieved 96.8% accuracy (30 of 31). For quadrant localization, technetium Tc99m sestamibi SPECT accuracy was 67.7% (21 of 31), multiphase multidetector 4D CT accuracy was 87.1% (27 of 31), and technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT accuracy was 93.5% (29 of 31). Reader diagnostic confidence was consistently ranked lowest for technetium Tc99m sestamibi SPECT and highest for technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT.

CONCLUSIONS

For left/right localization of parathyroid adenomas, all modalities performed equivalently. For quadrant localization, technetium Tc99m sestamibi SPECT + multiphase multidetector 4D CT is superior to technetium Tc99m sestamibi SPECT.

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.

Diagnosis performance of 99mTc-MIBI and multimodality imaging for hyperparathyroidism

This study aimed to examine the diagnosis performance of ^99mTc-methoxyisobutylisonitrisonitrile (^99mTc-MIBI) and multimodality imaging [ultrasound, single-photon emission computed tomography/computed tomography (SPECT/CT)] for hyperparathyroidism (HPT). From Nov. 2009 to Dec. 2015, clinical data of a total of 43 HPT patients (16 males and 27 females; 26-70 years old, average age: 51.60±10.66 years old) were retrospectively analyzed. Among them, 19 patients with primary hyperparathyroidism (PHPT) underwent ^99mTc-MIBI planar imaging, 24 [15 with PHPT and 9 with secondary hyperparathyroidism (SHPT)] underwent SPECT/CT hybrid imaging, and 41 (33 with PHPT and 8 with SHPT) had neck ultrasound imaging. Final diagnosis was determined by pathological examination after surgery. The positive rate was compared between different imaging modalities, and the correlation analysis was conducted between imaging results and lesion size or serum parathyroid hormone (PTH) level. The results showed that the total positive rates of ^99mTc-MIBI imaging, ultrasound, and the two combined imaging in the 43 HPT cases were 90.70% (39/43), 58.54% (24/41), and 100% (41/41), respectively. According to lesion numbers, the positive rates were 79.10% (53/67), 53.23% (33/62), and 88.71% (55/62), respectively. SPECT/CT hybrid images were positive in all the 24 patients who underwent this examination. The mean maximum diameters of the lesions in ^99mTc-MIBI positive and negative patients were 1.96±0.95 cm and 1.36±0.67 cm respectively, with statistically significant difference noted (P=0.03). The T/NT of ^99mTc-MIBI imaging at the early phase was correlated positively with serum PTH level (r=0.40, P=0.01). The T/NT of ^99mTc-MIBI imaging at both the early phase and the delay phase was correlated positively with lesion size (r=0.51, and r=0.45, respectively; P<0.01 for both). It was concluded that ^99mTc-MIBI imaging presents significant value for location diagnosis of HPT, especially when combined with SPECT/CT hybrid imaging or ultrasound. The ^99mTc-MIBI uptake correlates positively with serum PTH level and lesion size.

Differentiation of parathyroid carcinoma and adenoma by preoperative ultrasonography

Background Parathyroid carcinomas (PTC) are very rare. There have been a few studies on the contribution of ultrasound (US) in the diagnosis of PTC compared with parathyroid adenomas (PTA). Purpose To identify the differences between US findings of PTC and PTA in patients with primary hyperparathyroidism (PHPT). Material and Methods We enrolled seven patients with PTC and 32 consecutive patients with PTA whose diagnoses were confirmed by surgery at our institution between March 1994 and June 2015. We retrospectively compared the US features of the two groups, as well as the demographic, clinical, and biochemical characteristics (age, gender, palpability, and serum ionized calcium and parathyroid hormone [PTH] levels). Results The patients with PTC and PTA did not exhibit significant differences in terms of mean age (59.0 years versus 51.1 years; P = 0.2063), sex distribution (male:female, 4:3 versus 1:3; P = 0.1716), mean PTH levels (2855.0 pg/mL versus 1821.5 pg/mL; P = 0.2067), and mean ionized calcium levels (1.7 mMol/L versus 1.5 mMol/L; P = 0.1585) except palpability ( P < 0.0001). On US images, the PTCs were significantly larger (3.5 cm versus 1.9 cm; P = 0.0133) and exhibited higher incidences of heterogeneous echotexture ( P = 0.0002), irregular shape ( P < 0.0001), non-circumscribed margin ( P < 0.0001), intra-nodular calcifications ( P = 0.014), and local invasion ( P = 0.0004) compared to the PTAs. Conclusion In preoperative patients with PHPT, PTCs are differentiated from PTAs by their palpability and significant US features: large size, heterogeneous echotexture, irregular shape, non-circumscribed margin, intra-nodular calcifications, and local invasion.

Minimally Invasive Parathyroidectomy Versus Bilateral Neck Exploration for Primary Hyperparathyroidism

Primary hyperparathyroidism is a disease that is caused by excess parathyroid hormone (PTH) secretion from 1 or more of the parathyroid glands. Surgery is the only cure. Traditional surgical management consists of a 4-gland cervical exploration. Development of imaging specific to identification of parathyroid glands and application of the rapid PTH assay to operative management have made more minimal exploration possible. There are distinct advantages and disadvantages of minimally invasive parathyroidectomy (MIP) and bilateral neck exploration (BNE). The advantages of MIP seem to outweigh those of BNE, and MIP has replaced BNE as the operation of choice by many surgeons.

Endocrine scintigraphy with hybrid SPECT/CT

Nuclear medicine imaging of endocrine disorders takes advantage of unique cellular properties of endocrine organs and tissues that can be depicted by targeted radiopharmaceuticals. Detailed functional maps of biodistributions of radiopharmaceutical uptake can be displayed in three-dimensional tomographic formats, using single photon emission computed tomography (CT) that can now be directly combined with simultaneously acquired cross-sectional anatomic maps derived from CT. The integration of function depicted by scintigraphy and anatomy with CT has synergistically improved the efficacy of nuclear medicine imaging across a broad spectrum of clinical applications, which include some of the oldest imaging studies of endocrine dysfunction.

Proactive medicine: the "UCI 30," an ultrasound-based clinical initiative from the University of California, Irvine

This article discusses the benefits of integrating point-of-care diagnostic ultrasound into the four-year medical school curriculum. Handheld ultrasound devices have been used to teach medical students at the University of California (UC), Irvine, since August 2010, and the article explains how the use of this inexpensive, safe, and noninvasive tool enhances the ability of a physician conducting a standard physical exam to confirm suspected findings and uncover other suspected pathology at a reasonable cost. The authors describe the ultrasound curriculum at UC Irvine and the process of its implementation. In the appendix to the article, the authors describe the specific diagnostic benefits of using a handheld ultrasound device for each element of the Stanford 25 physical exam. Their ultrasound-enhanced approach to the physical exam is referred to as the "UCI 30." They make recommendations for how and when to integrate ultrasound into the physical exam. The article points out that early training of medical students in the use of ultrasound can avoid the diagnostic problems of ultrasound by maximizing students' comfort and ability to obtain accurate ultrasound images for diagnostic and procedural purposes.

Comparison of Tc-99m pertechnetate images with dual-phase Tc 99m MIBI and SPECT images in primary hyperparathyroidism

BACKGROUND

The purpose of this study was to evaluate the value of Tc-99m pertechnetate planar, dual-phase MIBI and MIBI-SPECT images in the determination and localization of parathyroid lesions.

MATERIALS AND METHODS

In this study, 38 patients who underwent operation for primary hyperparathyroidism were included. Tc-99m pertechnetate planar-pinhole imaging of the neck and then MIBI planar and SPECT images in supine position was performed. Late SPECT images were acquired 120 minutes after the injection. Early and late MIBI images were quantitatively evaluated.

RESULTS

Of the 38 patients, 30 of them had adenoma, 2 patients had hyperplasia and 6 of them were normal on planar images. Thirty-four of 38 patients were positive on SPECT images. SPECT images of the patients with positive results were matched with pathology results.

CONCLUSION

As a result, Tc-99m pertechnetate planar-pinhole, Tc-99m MIBI planar and SPECT images are useful for localization of parathyroid lesions especially in multinodular thyroid gland. However, US or CT images are necessary for more accurate localization and Tc-99m pertechnetate images are useful for interpreting and comparing with the early and late MIBI images.

Surgeon-driven thyroid interrogation of patients presenting with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (pHPT) is an increasingly prevalent disease affecting all age groups. The authors sought to determine the impact of a "thyroid interrogation" practice protocol on the surgical treatment of patients with the diagnosis of pHPT referred to a single surgeon.

STUDY DESIGN

We performed a retrospective review of prospectively gathered data on parathyroidectomy (PTX) patients undergoing both a prospective clinical thyroid evaluation and thyroid ultrasound between January 2008 and October 2012.

RESULTS

Only 5.6% of 468 PTX patients were referred to a single surgeon for both parathyroid and thyroid surgical evaluation; 31% of patients had known pre-existing thyroid disease (hypothyroidism most commonly), and 22% of patients had palpable thyroid abnormalities unrecognized in 67% of cases by the referring physician. Of the 468 patients, 2.6% had a history of classic head and neck radiation exposure, 2.6% a history of radio-iodine treatment, and 3% a family history of thyroid cancer. Thyroid abnormalities were found on ultrasound in 61% of patients, and 26% of patients underwent thyroid biopsies. Parathyroid and thyroid surgery was combined for 18.4% of patients; indications included obstructive symptoms (3.2%), hyperthyroidism (0.9%), intraoperative findings (5.1%), and concern for malignancy (9.2%). Malignancy was diagnosed in 23 patients (4.9%), only 8 of whom had been referred for thyroid evaluation.

CONCLUSIONS

The majority of patients referred for PTX had evidence of thyroid pathology. For an important minority of these patients, benign and malignant disease was identified that merited surgical treatment at the time of PTX. We recommend comprehensive thyroid evaluation of patients referred for PTX.

Efficacy of ⁹⁹mTc-sestamibi SPECT/CT for minimally invasive parathyroidectomy: comparative study with ⁹⁹mTc-sestamibi scintigraphy, SPECT, US and CT

PURPOSE

We evaluated the efficacy of (99m)Tc-sestamibi SPECT/CT for planning minimally invasive parathyroidectomy (MIP), comparing with dual phase (99m)Tc-sestamibi scintigraphy, (99m)Tc-sestamibi SPECT and conventional imaging (US and CT).

METHODS

Thirty-one patients (M:F = 10:21, range 35-78 years old) who showed high serum parathyroid hormone (intact PTH) level were included. (99m)Tc-sestamibi scintigraphy was performed 15 and 150 min after injection of (99m)Tc-sestamibi (555 MBq), and (99m)Tc-sestamibi SPECT/CT was obtained just after the delayed scan. Comparison study between imaging modalities was done by patient-based and lesion location-based analysis. The location of the lesion was confirmed by the operative finding. An operation was performed in 24 patients. Seven patients had normal (99m)Tc-sestamibi SPECT/CT, and followed for more than 6 months after SPECT/CT.

RESULTS

Among 24 patients, parathyroid adenoma was detected in 19 patients and the other 5 had parathyroid hyperplasia (total 35 lesions). (99m)Tc-sestamibi scintigraphy detected abnormal uptake in 15 patients with 24 lesions. Conventional imaging identified abnormal findings in 17 patients with 27 lesions. SPECT detected abnormal findings in 18 patients with 27 lesions. SPECT/CT identified abnormal findings in 24 patients with 35 lesions. SPECT/CT demonstrated 100 % sensitivity in a patient-based analysis. SPECT/CT exhibited significantly better sensitivity than (99m)Tc-sestamibi scintigraphy, SPECT and conventional imaging (p < 0.05). All lesion location was correctly identified to perform MIP. The final clinical diagnosis of 7 normal SPECT/CT patients was secondary hyperparathyroidism on 6 months follow-up.

CONCLUSIONS

We correctly identified the precise location of parathyroid adenomas or hyperplasia by (99m)Tc-sestamibi SPECT/CT which was helpful to perform MIP.