Abnormal Parathyroid Research Articles

Study of radioactivities in parathyroid and near tissues during radioguided parathyroidectomy

To determine the radioactivities in parathyroid and near tissues during radioguided parathyroidectomy in patients with hyperparathyroidism and the utility of parathyroidectomy in patients with negative (99m)Tc-sestamibi scans. Between August 2010 and August 2011, 21 patients underwent radioguided parathyroidectomy for hyperthyroidism. The levels of parathyroid hormone (PTH) and serum calcium before and after surgery were detected respectively. In vivo and ex vivo radioactivities in parathyroid and near tissues were examined. According to the radioactivity in parathyroid, the patients were divided into two groups, positive group and negative group. All data was descriptively analyzed and underwent a t test and an analysis of variance. In all patients both PTH and calcium levels decreased significantly after parathyroidectomy when compared to those before surgery (t' = 17.71 and t = 10.00, respectively, P < 0.001). In vivo and ex vivo radioactivities in enlarged parathyroid glands were higher than those in thyroid and fat tissue (F = 75.25 and 37.81, respectively, P < 0.001). In vivo and ex vivo radioactivities of the enlarged parathyroid with negative sestamibi scans were significantly greater than background radioactivity. There are significant differences in (99m)Tc-sestamibi radioactivities among enlarged parathyroid glands, thyroid glands and fat tissues. This radioguided technique is helpful to identify abnormal parathyroid gland in patients with hyperparathyroidism during parathyroidectomy.

Ectopic pituitary adenoma with empty sella in the setting of MEN-1 syndrome: detection with 68Ga-DOTANOC PET/CT

Patients with multiple endocrine neoplasia type-1 syndromes are known to have neuroendocrine tumors (NETs) involving the pituitary and gastroenteropancreatic region, in addition to the presence of parathyroid abnormalities. In rare instances adenomas in the ectopic pituitary gland have been reported. As pituitary gland and pituitary adenomas are known to express SSTRs, somatostatin receptor scintigraphy can be used for imaging. Somatostatin receptor-based PET/CT imaging using 68Ga-DOTANOC has become a popular noninvasive imaging modality for evaluation of patients with NETs. The application of 68Ga-DOTANOC PET/CT can be extended to multiple endocrine neoplasia type 1 patients, as is evident from this case study.

Neck ultrasonography as preoperative localization of primary hyperparathyroidism with an additional role of detecting thyroid malignancy

ObjectiveTo evaluate and compare the diagnostic performances of high-resolution ultrasonography and 99mTc-sestamibi scintigraphy for the preoperative localization of abnormal parathyroid glands and to evaluate the ability of US for additional diagnostic roles in detecting thyroid malignancy in patients with pHPT. Materials and methodsPreoperative localization images of 115 parathyroid adenomas from high-resolution ultrasonography (US) and 99mTc-sestamibi scintigraphy (SS) were studied from 105 patients, who had undergone parathyroidectomy. Sensitivity, accuracy, and positive predictive value were calculated for the identification of adenomas in lesions and patients for both US and SS, respectively, and US and SS diagnostic performances were compared using generalized estimating equation. ResultsPreoperative imaging by both modalities localized 105 (93.8%) of the 112 parathyroid lesions confirmed at surgery and histology. Sensitivity, accuracy, and positive predictive value were 93.1% and 92.2%, 90.4% and 89.5%, and 96.9% and 96.9% by US and SS, respectively, without any statistically significant differences (P=0.796, 0.796, 0.879). US found incidental thyroid nodules in 47 patients (47/107, 43.9%), and 7 patients (7/107, 6.5%) were confirmed to have malignancy based on pathology results (all had papillary thyroid carcinoma). ConclusionNeck ultrasonography and 99mTc-sestamibi scintigraphy are complementary methods of the preoperative localization of parathyroid adenomas. Neck ultrasounds add an additional thyroid gland evaluation, and can be useful in the detection of incidental thyroid gland lesions, especially malignant nodules.

Accuracy of Four-dimensional CT for the Localization of Abnormal Parathyroid Glands in Patients with Primary Hyperparathyroidism

To investigate multiphase multidetector four-dimensional computed tomography (CT) as a technique to correctly localize abnormal parathyroid glands in patients with primary hyperparathyroidism. Informed consent was waived by the institutional review body for this retrospective, chart review study. Radiology reports from four-dimensional CT and surgical notes were reviewed in 143 patients with primary hyperparathyroidism (35 men, 108 women; median ages, 58 and 60 years, respectively) who underwent parathyroid surgery between August 2004 and January 2007 and in whom four-dimensional CT predicted a single lesion. Accuracy of four-dimensional CT was stratified by patient and was determined separately for localization to the correct side and quadrant (upper and lower for each side), with surgical findings serving as standard of reference. In 143 patients, 148 abnormal parathyroid glands were found at surgery; 137 (93%) of these were weighed, with mean and median weights of 757 and 417 mg, respectively. Four-dimensional CT lateralized the abnormal glands with 93.7% accuracy (134 of 143). For localization according to quadrant, the accuracy was 86.6% (116 of 134). Four-dimensional CT has sufficiently high accuracy in presurgical localization to allow confident performance of unilateral parathyroidectomy in patients with sporadic primary hyperparathyroidism. The superior accuracy compared with that of ultrasonography and technetium 99m sestamibi scanning may be sufficient to allow four-dimensional CT to be used as the sole presurgical localization method.

Correlation of biochemical markers of primary hyperparathyroidism with single adenoma weight and volume.

Preoperative laboratory markers of primary hyperparathyroidism including serum parathormone (PTH), calcium and phosphate level may have some predictive value about the size and volume of the abnormal parathyroid gland tissue which needs to be resected in primary hyperparathyroidism. In a Prospective study from 2003 to 2010, 69 patients with parathyroid adenoma were enrolled. The correlation between preoperative serum PTH, calcium and phosphate level with adenoma's weight and volume was analyzed separately. Adenoma volume was calculated via an equation for the volume of a spheroid object. The data were analyzed via a multiple analysis of variance, and a correlation coefficient was calculated. The level of significance was set at p _ .05. There was a significant correlation between adenoma weight and serum calcium and parathormone levels (p = .0001 and p = .0001, respectively). There was no significant correlation between adenoma weight and serum phosphate. With respect to adenoma weight, there was a significant relationship with parathormone levels and serum calcium (p = .0001 and p = .0001, respectively). There was no significant relationship between serum phosphate and aden2oma weight. Preoperative serum PTH and calcium levels may be valuable in predicting parathyroid adenoma volume and weight in primary hyperparathyroidism for a single adenoma.

Management of Patients with Primary Hyperparathyroidism and Concurrent Thyroid Disease: An Evolving Field

The presence of thyroid disease can complicate the evaluation and surgical management of patients with primary hyperparathyroidism (PHPT). Retrospective analysis has shown that approximately 20–50% of patients with PHPT also have thyroid disease. 1–3 The reported incidence of thyroid malignancy in patients with PHPT is approximately 3–4%. 1,4 There is no uniformly accepted protocol for the evaluation of patients with thyroid pathology before operative intervention for PHPT. Neck exploration for PHPT normally provides excellent access to the thyroid, whereas minimally invasive parathyroidectomy offers a more limited exposure of the thyroid gland. The increased application of the minimally invasive approach has increased the reliance on preoperative imaging. Modalities for localizing abnormal parathyroid glands such as 99m Tcsestamibi scintigraphy (Tc-MIBI), I-123, and neck ultrasound can also identify thyroid pathology. Onkendi et al. analyzed the results from a series of patients with PHPT and concurrent thyroid nodules who underwent dual-isotope Tc-MIBI and radioiodine (I-123) subtraction imaging. 5 The most significant finding is that the phenotype Tc-MIBI-Hot/I-123-Cold has a negative predictive value for malignancy of 90%. Patients with the Hot/Cold phenotype were almost 3 times as likely to have a malignant thyroid lesion, indicating that these patients should be evaluated more aggressively with a lower threshold for fine-needle aspiration biopsy (FNAB) and thyroid resection. Patients with thyroid nodules that had any other phenotype (Hot/Hot, Cold/Hot, Cold/Cold) had a much lower potential for thyroid malignancy, and therefore, it may be appropriate to treat these patients with close follow-up rather than FNAB or thyroid resection. Onkendi et al. further identified a group of patients who were found during surgery to have a false-positive imaging result, characterized by a Hot/Cold scan with no abnormal parathyroid found corresponding to the imaging localization. Patients with underlying thyroid malignancy were more likely to have a false-positive parathyroid scintigraphy (45% compared to 22% of patients with benign thyroid disease). These data indicate that patients undergoing neck exploration who are found to have a false-positive dual imaging result should have further intraoperative evaluation for the potential of an undiagnosed thyroid malignancy.

Comparative Study of Preoperative Imaging Detection and Localization Test for Hyperparathyroidism

Received April 12, 2012 Revised June 15, 2012 Accepted June 18, 2012 Address for correspondence Kyung Tae, MD Department of OtolaryngologyHead and Neck Surgery, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-792, Korea Tel +82-2-2290-8585 Fax +82-2-2293-3335 E-mail kytae@hanyang.ac.kr Background and ObjectivesZZAccurate preoperative localization of abnormal parathyroid gland is essential for successful parathyroidectomy. The aim of this study was to evaluate the accuracy of a localization test for hyperparathyroidism including ultrasonography (US), computed tomography (CT) and Tc-sestamibi scan. Subjects and MethodZZWe studied 47 patients with hyperparathyroidism who underwent parathyroidectomy from January 2003 through December 2010, retrospectively. Tc-sestamibi scan, US and CT were carried out as a preoperative localization test and their accuracy were analyzed according to the size, location and pathology of parathyroid lesions. ResultsZZThe accuracy of Tc-sestamibi scan, US and CT were 93%, 77% and 65%, respectively. The accuracy of Tc-sestamibi scan and CT combined was 94% and US and CT 73%. The accuracy of combination of US and Tc-sestamibi scan was 96%, which was not different depending on size, location and pathology of parathyroid lesions. ConclusionZZThe combination of Tc-sestamibi scan and US is the most effective method for preoperative detection and the localization of hyperparathyroidism. Korean J Otorhinolaryngol-Head Neck Surg 2012;55:565-70

A Comparison of Outcomes for Younger and Older Adult Patients Undergoing Surgery for Primary Hyperparathyroidism

In adolescents and young adults, primary hyperparathyroidism (PHPT) is an uncommon diagnosis. We compared the clinical characteristics of these patients to those of older adult patients with PHPT. We hypothesized that PHPT in adolescents and young adults is more often caused by single-gland disease and is amenable to minimally invasive parathyroidectomy (MIP). We retrospectively reviewed the medical records of 452 consecutive patients who had surgery for PHPT. Patients ranged in age from 13 to 94 years and were dichotomized into younger (age <30 years, n = 17, 3.8%) and older (age ≥ 30 years, n = 435, 96.2%) patients. Continuous baseline and intraoperative and postoperative measures were not normally distributed and were summarized with medians and interquartile ranges (IQRs). Groups were compared using Wilcoxon rank sum test or Fisher exact test, and significance was set at P < .05. Median [IQR] age was 24 [23-27] years for the younger group and 58 [51-66] years for the older group. Though not statistically significant, a smaller proportion of the younger patients compared with the older patients had a positive (99m)Tc-sestamibi scan (71%; 95% confidence interval [95% CI] = 44-90% vs. 83%; 95% CI = 79-86%) and showed a suspected parathyroid adenoma on ultrasound (65%; 95% CI = 38-86% vs. 80%; 95% CI = 76-83%). The younger and older age groups did not significantly differ on preoperative serum PTH levels (median [IQR]: 111 [76-145] pg/ml vs 110 [84-152] pg/ml; P = .73 respectively). The younger group had higher serum calcium levels (11.6 [11.1-12.2] mg/dl) compared with the older group (11.1 [10.7-11.5] mg/dl; P = .01). MIP was performed less frequently on the younger patients (70.6%) compared with older patients (88.7%; P = 0.04). Though the incidence of a single adenoma was somewhat more frequent in older patients (90%; 95% CI = 87-93%) than in younger patients (82%; 95% CI = 57-96%) it was the most frequent cause of PHPT in the younger patients. The younger and older groups did not significantly differ on percent drop from baseline for intraoperative PTH monitoring (81.7 vs 79.3%; P = .46), respectively. Younger patients with PHPT present with significantly higher serum calcium levels than older patients. However, younger patients are less likely to localize abnormal parathyroid glands on sestamibi or ultrasound. Though younger patients appear to have a higher incidence of hyperplasia compared with older patients, single gland disease is still the overall most frequent cause. Our data suggest that MIP should be more frequently considered in younger patients because of the high incidence of single gland disease.

Hyperparathyroid crisis: The timing of surgery

Hyperparathyroid crisis is a rare, critical, and potentially fatal disease. The aim of this study was to classify different clinical courses of this disease, according to their preoperative medical responses and suggest the proper timing for surgery. Patients who had undergone parathyroidectomies for hyperparathyroid crisis, were enrolled between January 1, 1994 and January 31, 2009. Preoperative medical treatment and responses in terms of predisposing factors, preoperative localization, operative and pathological findings, postoperative outcome, and intervals from medicine to surgery, were retrospectively reviewed. A total of 11 patients, receiving more than 72 hours of medical treatment, were divided into three types by preoperative medical responses. These included: Type I (three patients were resistant to medicine with persistent serum Ca>14mg/mL and were eventually treated with emergency surgery; two died of postoperative respiratory and hepatic failure), Type II (six patients with abnormal serum Ca<14mg/mL) and Type III (two patients in whom serum calcium returned to normal preoperatively. One patient was successfully treated with emergency surgery 18 hours post-hospitalization). We found no method for predicting the medical response, but all Type I patients exhibited high serum Ca>14mg/mL after 48 hours of medical treatment. All abnormal parathyroid glands were >1.8cm in length and easily detectable using preoperative ultrasonography. Because the response to pharmaceutical treatment of hyperparathyroid crisis is unpredictable, relieving the patient's dehydration is necessary first. Making a definite diagnosis and performing an early parathyroidectomy within 48 hours are then required, especially in patients exhibiting poor medical response.

Approach to the Patient with Persistent or Recurrent Primary Hyperparathyroidism

Reoperative parathyroid surgery may be required in patients who have persistent primary hyperparathyroidism after an unsuccessful operation and in patients who had an initially successful exploration but develop recurrent disease at an interval greater than 6 months postoperatively. Additionally, patients who have had significant surgery in the cervical region, particularly total thyroidectomy, should be considered in this group because they pose identical technical challenges that in the past have resulted in suboptimal cure and complication rates. These patients require a meticulous review of their historical, biochemical, imaging, and operative data to confirm the diagnosis, to evaluate the possibility of familial forms of hyperparathyroidism, and to confirm the indications for surgery. Once a patient is deemed an appropriate surgical candidate, sequential imaging is required to yield a roadmap to guide surgical intervention. These reoperative procedures require an experienced parathyroid surgeon armed with intraoperative adjuncts to locate the offending parathyroid gland(s) and remove them while minimizing collateral injury, particularly to the recurrent laryngeal nerves. These patients are also at increased risk of postoperative hypocalcemia that can be life-threatening. Despite these concerns, an experienced endocrine team can diagnose persistent or recurrent hyperparathyroidism, localize residual abnormal parathyroid glands, and perform surgical intervention with success and complication profiles that approximate those achieved in the unexplored patient.

A Meta-analysis of Preoperative Localization Techniques for Patients with Primary Hyperparathyroidism

Reported accuracy of preoperative localization imaging for primary hyperparathyroidism (pHPT) varies. The purpose of this study is to determine the accuracy of ultrasound, sestamibi-single photon emission computed tomography (SPECT), and four-dimensional computed tomography (4D-CT) as preoperative localization strategies. A meta-analysis was performed of studies investigating the accuracy of ultrasound, sestamibi-SPECT, and 4D-CT for preoperative localization in pHPT. Electronic databases were systematically searched, and two independent reviewers reviewed results using specific criteria. Study quality was assessed using a validated measure for diagnostic imaging studies. Study heterogeneity and pooled results were calculated. 43 studies met criteria for inclusion, and data were available for extraction in 19 ultrasound, 9 sestamibi-SPECT, and 4 4D-CT studies. Ultrasound had pooled sensitivity and positive predictive value (PPV) of 76.1% (95% CI 70.4-81.4%) and 93.2% (90.7-95.3%), respectively. Sestamibi-SPECT had pooled sensitivity and PPV of 78.9% (64-90.6%) and 90.7% (83.5-96.0%), respectively. Only two 4D-CT studies investigated patients undergoing initial parathyroidectomy. Results suggested sensitivity and PPV of 89.4% and 93.5%, respectively. Ultrasound and sestamibi-SPECT are similar in ability to preoperatively localize abnormal parathyroid glands in pHPT. Accuracy may be improved with 4D-CT; however, further investigation is required. Choice of preoperative imaging strategy depends on numerous patient, institutional, and economic factors of which the surgeon must be aware.

A comparative study of pre-operative imaging methods in patients with primary hyperparathyroidism: ultrasonography, 99mTc sestamibi, single photon emission computed tomography, and magnetic resonance imaging.

This study compares the accuracy rates achieved in ultrasonography (US), 99mTc-sestamibi (MIBI), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) as imaging methods used in the pre-operative localization of the enlarged parathyroid glands. For the purposes of this study, US, MIBI, SPECT, and MRI were performed on 98 patients with primary hyperparathyroidism (pHPT). All patients underwent parathyroidectomy. Pre-operative localization of an abnormal parathyroid gland was successfully performed in 82 of the cases scanned with US (83.7%), while the result was 66 in the cases scanned with MIBI (67.3%), 71 of the cases were successfully localized with SPECT (72.4%), while MRI revealed the diseased gland in only 60 of the total cases (61.2%). In MIBI-positive and -negative patients there was a statistically significant difference among cases in terms of adenoma volume (1.30±1.51 vs 0.58±0.91, p<0.05). Sensitivity, specificity and diagnostic accuracy values were 87.2%, 25.0%, and 83.0%; 70.2%, 50.0%, and 69.4%; 75.5%, 50.0%, and 74.5%; 63.8%, 50.0%, and 63.3% for US, MIBI, SPECT, and MRI, respectively. The respective values for sensitivity, specificity, and diagnostic accuracy were 94.9%, 25.0%, and 91.1% when US was combined with MIBI. Combining US and MIBI as imaging methods for pre-operative imaging of pHPT often produces more satisfactory results. While the accuracy of US is relatively low in the ectopic localizations, the size of the lesion can be an important factor in the accuracy achieved with MIBI.

Parathyroid localization with modified 4D‐computed tomography and ultrasonography for patients with primary hyperparathyroidism

In this article, we report our decade-long experience in using modified 4D-computed tomography in combination with ultrasonography (Mod 4D-CT/US) to localize abnormal parathyroid glands in patients with primary hyperparathyroidism. Retrospective medical record review at a university-based academic medical center. Patients with primary hyperparathyroidism who underwent a Mod 4D-CT/US and parathyroidectomy between January 1998 and May 2009 were included in the study. Results from preoperative localization studies were compared with operative findings, pathologic data, and biochemical measurements to assess the sensitivity and specificity as well as the positive and negative predictive values of Mod 4D-CT/US. Mod 4D-CT/US demonstrated 94% sensitivity and 96% specificity when these imaging studies were used to lateralize the hyperfunctioning parathyroid glands to one side of the neck. In regard to localizing abnormal parathyroid glands to a specific quadrant of the neck (i.e., right-left; superior-inferior), the sensitivity and specificity of Mod 4D-CT/US was 82% and 93%, respectively. Mod 4D-CT/US had a 92% positive predictive value for single-gland disease and 75% for multigland disease. The negative predictive value for single and multigland disease (MGD) were 73% and 92%, respectively. Mod 4D-CT/US provides excellent sensitivity and specificity in terms of localizing abnormal parathyroid glands to the correct side and quadrant in patients with primary hyperparathyroidism, and it correctly identifies many patients with MGD.

Incidental Parathyroid Disease during Thyroid Surgery: Should We Remove Them?

Aim. Despite an incidence of parathyroid “incidentalomas” of 0.2%–4.5%, only approximately 135 cases have been reported in the literature. We present eight patients in whom an incidental abnormal parathyroid gland was found during routine thyroid surgery. We have reviewed the literature and postulate whether these glands could represent further evidence of a preclinical stage of primary hyperparathyroidism. Methods. A retrospective analysis of all 236 thyroid operations performed by a single surgeon was performed to identify patients in whom abnormal parathyroid tissue was removed at surgery. Results. 8/236 patients (3.39%) had a single macroscopically abnormal parathyroid gland removed and sent for analysis. Seven patients were found to have histological evidence of a parathyroid adenoma or hyperplasia. None of the patients had abnormal serum calcium detected preoperatively. Postoperatively, four patients had normal calcium, three had temporary hypocalcaemia and one refused followup. No patients had recurrent laryngeal nerve impairment. Conclusions. Despite the risk of removing a histologically normal gland, we believe that when parathyroid “incidentalomas” are found during surgery they should be excised and sent for histological analysis. We have found this to be a safe procedure with minimal morbidity to the patient. As the natural history of primary hyperparathyroidism is better understood, these glands found in normocalcaemic patients may in fact represent the early or preclinical phase of the disease. By removing them at the original operation, the patient is saved redo neck surgery with its high complication rate as or when clinically apparent primary hyperparthryoidism develops in the future.

Minimally Invasive Parathyroid Surgery, The Norman 20% Rule: Is It Valid?

The 20 per cent rule proposed by Norman established a guideline using radioactivity in the minimally invasive radioguided parathyroidectomy (MIRP) technique to localize and confirm removal of an abnormal parathyroid gland in patients with primary hyperparathyroidism. If radioactivity in the resected gland was at least 20 per cent of excision site/background radioactivity, the 20 per cent rule was satisfied. Patients meeting these criteria underwent unilateral MIRP without intraoperative parathyroid hormone assay or intraoperative frozen section. The study aim was to independently evaluate the 20 per cent rule in MIRP patients with primary hyperparathyroidism. Using the University of Louisville Parathyroid Database from January 1, 1999 to December 31, 2007, 216 MIRP patients with complete radioguided and postoperative management data were identified. The average percentage of ex vivo parathyroid gland radioactivity compared with excision site/background radioactivity was 107 per cent with a range from 14 to 388 per cent. For 99 per cent (196/198) radioactivity recorded from the excised gland was at least 20 per cent of radioactivity recorded from the excision site. Normocalcemia was documented in 98.5 per cent (195/198) at 12 month follow-up. Our data supports the 20 per cent rule in that in 99 per cent of MIRP patients the resected gland radioactivity was at least 20 per cent of excision site radioactivity allowing localization and confirmation of an overactive gland without intraoperative parathyroid hormone monitoring or tissue analysis.

Surgeon-Performed Ultrasound Is Superior to 99Tc-Sestamibi Scanning to Localize Parathyroid Adenomas in Patients with Primary Hyperparathyroidism: Results in 516 Patients over 10 Years

Surgeon-performed cervical ultrasound (SUS) and 99Tc-sestamibi scanning (MIBI) are both useful in patients with primary hyperparathyroidism (PHPT). We sought to determine the relative contributions of SUS and MIBI to accurately predict adenoma location. We performed a database review of 516 patients undergoing surgery for PHPT between 2001 and 2010. SUS was performed by 1 of 3 endocrine surgeons. MIBI used 2-hour delayed anterior planar and single-photon emission computerized tomography images. Directed parathyroidectomy was performed with extent of surgery governed by intraoperative parathyroid hormone decline of 50%. SUS accurately localized adenomas in 87% of patients (342/392), and MIBI correctly identified their locations in 76%, 383/503 (p < 0.001). In patients who underwent SUS first, MIBI provided no additional information in 92% (144/156). In patients who underwent MIBI first, 82% of the time (176/214) SUS was unnecessary (p = 0.015). In 32 patients SUS was falsely negative. The reason for these included gland location in either the deep tracheoesophageal groove (n = 9) or the thyrothymic ligament below the clavicle (n = 5), concurrent thyroid goiter (n = 4), or thyroid cancer (n = 1). In 13 cases, the adenoma was located in a normal ultrasound-accessible location but was missed by the preoperative exam. In the 32 ultrasound false-negative cases, MIBI scans were positive in 21 (66%). Of the 516 patients, 7.6% had multigland disease. Persistent disease occurred in 4 patients (1%) and recurrent disease occurred in 6 (1.2%). When performed by experienced surgeons, SUS is more accurate than MIBI for predicting the location of abnormal parathyroids in PHPT patients. For patients facing first-time surgery for PHPT, we now reserve MIBI for patients with unclear or negative SUS.

Images de soustraction TEMP, en double isotope, 99mTc-sestamibi/ 123I fusionnées au scanner : intérêt chez des patients présentant une hyperparathyroïdie

Purpose To assess dual-tracer imaging of hybrid SPECT/CT (S/CT) compared to planar scintigraphy (S/PL) and ultrasounds (US), in preoperative localization hyperparathyroidism. Methods Dual tracer S/CT, S/PL and US for preoperative localization were performed in 99 patients with hyperparathyroidism. Patients with single-gland and multiple gland disease (MGD) were evaluated. For S/PL and S/CT, 15 MBq of 123I were given and 2 hours later, 555 MBq/kg of 99mTc-MIBI was injected. Images were acquired simultaneously using appropriate windows in S/PL and S/CT, then compared to US. Thus, the predicted positions were compared to the intraoperative findings and abnormal parathyroid glands were measured. Results Seventy-five patients underwent invasive surgery, which served as standard. Sixty-seven adenomas and 17 MGD were found on 70 patients. Sensitivity for US, S/PL and S/CT was respectively 69, 82 and 83%; and specificity was 96, 91 and 93% with an overall kappa-coefficient of 0.64, 0.73 and 0.76. US, S/PL and S/CT were correlated with the size of abnormal glands even if US remains the most accurate measuring technique. S/CT was able to predict the true position of the abnormal gland in 80% of cases. Conclusion Dual-isotope planar imaging and S/CT were statistically significantly superior to US imaging in sensitivity. The addition of CT to SPECT further improves parathyroid adenoma localization and predicts the size, which can help for mini-invasive surgery.

Current Understanding and Treatment of Primary Hyperparathyroidism

There have been four major events over the last century that have contributed to the better understanding and treatment of primary hyperparathyroidism: the routine measurement of serum calcium with recognition of hypercalcemia, the secured diagnosis with measurement of elevated parathyroid hormone (PTH) levels, the preoperative localization of hypersecreting parathyroid gland(s), and the use of intraoperative measurement of PTH dynamics. Targeted parathyroidectomy guided by intraoperative parathyroid hormone monitoring (IPM) through a small cervical incision has replaced traditional bilateral neck exploration (BNE) as the initial approach in the surgical treatment of patients with primary hyperparathyroidism at many medical centers worldwide. Preoperative Tc-99m-sestamibi localization scans and/or ultrasound serve as an important prerequisite for successful targeted parathyroidectomy. Operative success rates are further improved by IPM before and after removal of all abnormal parathyroid glands. When intraoperative PTH levels are reduced by more than 50% from the highest pre-incision or pre-excision PTH level after resection of an abnormal gland, successful operative resection is assured with a predictive cure rate of > 95%. The advantages of targeted parathyroidectomy in the ambulatory setting include improved cosmetic results, decreased postoperative pain, shorter operative time, decreased hospitalization and rapid postoperative recovery with a success rate comparable to BNE. This article reviews the current understanding and treatment of primary hyperparathyroidism. PRIMARY HYPERPARATHYROIDISM

Near-infrared autofluorescence for the detection of parathyroid glands

A major challenge in endocrine surgery is the intraoperative detection of parathyroid glands during both thyroidectomies and parathyroidectomies. Current localization techniques such as ultrasound and sestamibi scan are mostly preoperative and rely on an abnormal parathyroid for its detection. In this paper, we present near-infrared (NIR) autofluorescence as a nonintrusive, real-time, automated in vivo method for the detection of the parathyroid gland. A pilot in vivo study was conducted to assess the ability of NIR fluorescence to identify parathyroid glands during thyroid and parathyroidectomies. Fluorescence measurements at 785 nm excitation were obtained intra-operatively from the different tissues exposed in the neck region in 21 patients undergoing endocrine surgery. The fluorescence intensity of the parathyroid gland was found to be consistently greater than that of the thyroid and all other tissues in the neck of all patients. In particular, parathyroid fluorescence was two to eleven times higher than that of the thyroid tissues with peak fluorescence occurring at 820 to 830 nm. These results indicate that NIR fluorescence has the potential to be an excellent optical tool to locate parathyroid tissue during surgery.

Re-explorative Parathyroid Surgery for Persistent and Recurrent Primary Hyperparathyroidism

ABSTRACT Primary hyperparathyroidism (HPT) is treated by parathyroidectomy. Excision of abnormal parathyroid tissue is curative in the majority of cases. Postoperative persistent or recurrent HPT has been reported up to 30%. The purpose of this study was to evaluate the role of imaging techniques and determine the efficacy of reexplorative surgery. A total of 306 patients underwent parathyroidectomy between 2000 and 2009. Twelve patients (3.9%) were not cured. Two patients declined further treatment, the other 10 patients underwent further investigation and surgery. Imaging and results of redo surgery together with associated complications were evaluated. All 10 patients were investigated with sestamibi, which accurately localized aberrant parathyroid tissue in three cases and ultrasound scans which also localized three cases. CT was useful in one of the three cases for which it was used. PET and MRI were not helpful. Twelve glands were resected, six adenomas, five hyperplastic and one normal gland. Nine of the 10 reoperated patients became normocalcemic. Complications included a bilateral recurrent laryngeal paresis. In total, 317 operations were performed and 303 of 306 (99%) patients were cured. Redo surgery for HPT is challenging and carries higher risks than primary surgery. Sestamibi and ultrasound scans are the most helpful imaging modalities. When there is concordance a targeted approach may be considered, otherwise a more extensive dissection is required. Redo parathyroid surgery should be considered, even if scans are unhelpful, for patients who are symptomatic or young or have a persistently high calcium level.