Determinants of Tc-99m sestamibi SPECT scan sensitivity in primary hyperparathyroidism

Background

The aim of this study was to evaluate the influence of patient and adenoma characteristics on ^99mTc-methoxy isobutyl isonitrile (MIBI) scan performance in individuals diagnosed with primary hyperparathyroidism (PHP).

Methods

Records of patients undergoing parathyroidectomy for PHP over 6 years at a single center were reviewed.

Results

The overall true-positive (TP) rate for ^99mTc-MIBI scans was 56%. Adenomas sized 1.9 to 3.5 cm were more likely to have TP scans than 0.3-cm to 1.8-cm adenomas (74% vs 40%, P < .001). Preoperative ionized calcium levels between 1.49 and 1.72 mmol/L were more likely to have TPs than levels between 1.27 and 1.48 mmol/L (65% vs 47%, P < .05). No single class of medication was shown to significantly effect TP rates. A decrease in TP rate was observed for larger adenomas in patients on ≥1 medication (74% vs 65%, P = .05).

Conclusions

In PHP, ^99mTc-MIBI scan positivity is most related to adenoma size and preoperative ionized calcium level.     

Minimally invasive endoscopic-assisted parathyroidectomy for primary hyperparathyroidism

Background: Minimally invasive surgery for primary hyperparathyroidism (pHPT) depends on both an accurate preoperative localization and the availability of intraoperative parathyroid hormone monitoring. Methods: Patients with sporadic pHPT and one unequivocally enlarged parathyroid gland on preoperative imaging underwent endoscopic-assisted parathyroidectomy. Intraoperative rapid parathyroid hormone (quick PTH) monitoring was performed, and surgical success was confirmed when there was a >50% decrease in quick PTH level 10 min after excision as compared with the baseline level at induction. The surgical outcome and the use of preoperative localization, together with the role played by quick PTH assay in enhancing the operative success, were evaluated. Results: From 1999 to 2002, 66 of 107 patients (62%) were selected for this approach. The accuracy of ^99mTc-Sestamibi scintigraphy and ultrasonography was 97% and 70%, respectively. Conversion was required in four cases due to technical problems, and four additional patients failed to show a significant decline in quick PTH levels postexcision. Two patients underwent cervical exploration without the finding of any additional pathology, and another two patients had a delayed drop in quick PTH that was confirmed 30 min postexcision. All patients had a solitary adenoma and were cured of hypercalcemia during a median follow-up of 9 months. Conclusions: Minimally invasive endoscopic-assisted parathyroidectomy can be performed expeditiously in a select group of patients based on ^99mTc-Sestamibi scintigraphy. The use of quick PTH assay can ensure surgical success, but careful interpretation of the results is mandatory.     

Scandinavian quality register for thyroid and parathyroid surgery: audit of surgery for primary hyperparathyroidism

Background and aim Scandinavian Quality Register for Thyroid and Parathyroid Surgery is an on-line web-based database with the aim to improve the quality of thyroid and parathyroid surgery. Preliminary data from surgery for primary hyperparathyroidism are reported here. Materials and methods Fifteen departments registered 806 operations, with 639 women (79.7%) and 167 men. The median age of the patients was 62 years. Results Approximately 95.4% of the patients had sporadic disease and first time operation was performed in 93.8% of the patients. Localization examinations were performed in 524 patients (65%); sestamibi scintigraphy in 413 patients, with a true positive adenoma localization in 64.4% and ultrasound in 293 patients with adenoma localization in 61.1%. Bilateral neck exploration was performed in 66.8%, unilateral exploration in 16.1%, and focused minimal invasive surgery in 17.1%. In 301 patients planned for limited parathyroid exploration, conversion to bilateral neck surgery occurred in 11%. The cure rate, based on short follow-up, was 91.9%. Postoperative hypocalcemia occurred in 11.4% of the patients, and was associated with reoperation, concomitant thyroid operation, and the weight of excised parathyroid tissue. Conclusion Localization examinations are performed in 2/3 of the patients, but limited neck exploration was performed in only approximately 1/3 of the operations. The cure rate was lower and postoperative hypocalcemia was more frequent than expected. Presented at the 2nd Biannual Congress of the ESES, May 2006, Krakow, Poland.     

Total body calcium mass in primary hyperparathyroidism and long-term changes

Summary The total body calcium mass of patients with primary hyperparathyroidism was measured by whole-body neutron activation analysis. Among 14 untreated patients, the calcium mass was significantly subnormal in 2. Long-term follow-up in 4 unoperated patients showed that the calcium mass remained unchanged in 3; in the 4th patient, parathyroidectomy was carried out after the 18th month of follow-up. Her total body calcium fell by 16% before operation, but was nearly regained in the following 3 years. In 1 patient followed for 32 months after parathyroidectomy, the calcium mass remained unchanged. After a follow-up in 4 additional patients for an average of 15 months, the calcium mass remained unchanged in 3, whereas the 4th showed a significant decrease 12 months after the first measurement.     

Benefits of surgeon-performed ultrasound for primary hyperparathyroidism

Background  Focused, minimally invasive parathyroidectomy (MIP) is widely accepted when preoperative imaging localizes a single parathyroid adenoma. Many surgeons use ^99mTc-sestamibi scintigraphy (MIBI) +/−, a cervical ultrasound for preoperative localization. We propose that surgeon-performed ultrasound (SUS) is the only imaging modality required in most patients with primary hyperparathyroidism (pHPT), resulting in patient convenience and reduced cost. Materials and methods  Since July 2006, patients with pHPT underwent MIP based solely on a positive SUS. Intraoperative parathyroid hormone assay was used to determine the extent of operation. A retrospective review from July 2006 through December 2008 identified 160 patients who underwent parathyroidectomy after SUS on their initial office visit. Results  SUS correctly identified an enlarged parathyroid gland in 119/160 (74%) patients. In 41 patients, SUS was the only localizing study. MIBI was done in 119 patients. In 54 patients, SUS confirmed the MIBI, and in 28 patients with a negative MIBI, SUS was positive. In the 41 patients with a negative SUS, an MIBI was positive in ten. Ninety-eight patients had MIP. Theoretically, 85 MIBIs were unnecessary because of a positive SUS corresponding to a potential cost savings of at least $90,000. Conclusion  SUS to localize parathyroid adenomas is accurate and facilitates MIP. It provides substantial cost savings and patient convenience and should be the first diagnostic procedure performed for patients suspected to have pHPT. MIBI can be reserved for those patients in whom ultrasound has failed to localize a parathyroid gland. Best of endocrine surgery in Europe 2009.     

原发性甲状旁腺功能亢进症的围手术期处理

目的：探讨围手术期处理对治疗原发性甲状旁腺功能亢进症（primary hyperparathyroidism,PHPT）的影响。方法：对近10年治疗26例PHPT的围手术期处理进行回顾性分析。结果：病人术前血清钙3．31mmol/L,5例出现高血钙危象（血清钙3．7－4．5mmol/L）。术后4d血清钙降低至最低点1．74mmol/L。血清甲状旁腺激素由术前1050．7pg/ml恢复至正常的17．12pg／ml。有2例由于未能及时治疗而死亡。全组累积死亡率为11．5％（3／26例）。分别为心搏骤停和左心功能不全。结论：重视围手术期的处理是PHPT治疗的重要环节;对高血钙危象的有效治疗必须尽早开始,以挽救病人生命。     

Role of cervical ultrasound in detecting thyroid pathology in primary hyperparathyroidism

Background

Minimally invasive parathyroidectomy for primary hyperparathyroidism is made possible with accurate preoperative imaging. In addition to the detection of parathyroid adenomas, cervical ultrasound also provides concomitant assessment of the thyroid gland, and many surgeons believe that it is essential. However, the incidental identification of thyroid nodules may then subject patients to further workup and potentially invasive thyroid procedures. We sought to determine the long-term consequence of omitting preoperative ultrasound on the development of thyroid pathology and cancer.

Methods

At our institution, 222 patients with primary hyperparathyroidism underwent parathyroidectomy without preoperative cervical ultrasound from 1990–2001. Thyroid pathology discovered by follow-up after parathyroidectomy, subsequent biopsy, and surgical interventions were analyzed.

Results

Of the 222 patients who underwent parathyroidectomy, the mean age was 55 ± 1 y and 149 were female (67%). In the course of their follow-up after parathyroidectomy, 13 patients (6%) received a cervical ultrasound, and seven of 13 (3%) underwent fine needle aspiration of a thyroid nodule. Only one of seven (0.4% of all patients) was ultimately diagnosed with thyroid cancer. Four additional patients were discovered to have thyroid malignancies as a result of intraoperative decision making. All five patients are currently alive with an average follow-up time of 14.9 ± 1.6 y. No patients in this series had an unnecessary thyroid intervention.

Conclusions

In patients who underwent parathyroidectomy without a preoperative ultrasound, only a small number (0.4%) were subsequently diagnosed with thyroid cancer. Furthermore, omission of ultrasound during the localization of parathyroid glands does not have a negative impact on the diagnosis of thyroid pathology as all patients who had thyroid cancer had good outcomes, and in fact, may prevent unnecessary thyroid interventions. Therefore, the use of cervical ultrasound for parathyroid localization should be considered optional rather than essential.     

Bone and primary hyperparathyroidism

Primary hyperparathyroidism (PHPT) is a disease caused by excessive and inappropriate secretion of parathyroid hormone resulting in hypercalcemia. It is usually diagnosed incidentally in case of hypercalcemia, osteoporosis or, more rarely, renal involvement such as lithiasis. The clinical presentation reflects hypercalcemia and involves several organs, mainly the cardiovascular system, bone, and kidneys. However, most patients with PHPT are asymptomatic. The diagnosis is biological, obvious when serum calcium and parathyroid hormone levels are high, but difficult when one of these two values is normal. The diagnosis of normocalcemic PHPT is possible only after ruling out all causes of secondary hyperparathyroidism. Parathyroid imaging does not contribute to the positive diagnosis but guides surgery and rules out an associated thyroid abnormality. Parathyroid surgery is the gold standard treatment. Parathyroid surgery is indicated in the presence or risk of complications, and it is the only treatment that prevents fractures. Pharmaceutical treatments have only limited effects on complications and are limited to cases where surgery is contraindicated. After parathyroid surgery, the use of bisphosphonates must be avoided as they seem to interfere with the parathyroidectomy's fracture-preventing effects. In the absence of surgical indication, medical monitoring of patients includes assessment of laboratory values, bone density, and renal function.     

原发性甲状旁腺功能亢进的诊治

目的：总结原发性甲状旁腺功能亢进(PHPT)的诊治经验。方法：回顾性分析2001～2005年上海一家三级 医院外科手术经病理证实的原发性甲状旁腺功能亢进的诊治经验。结果：经手术病理证实的原发性甲状旁腺功能亢 进共20例。其中颈部单发腺瘤13例，异位(胸腔纵隔)单发腺瘤2例，复发1例(因为单发腺瘤切除不彻底)，多发腺 瘤和增生各1例，恶性2例。骨病型12例，骨肾混合型7例，肾型1例。AKP 升高17例，PTH 升高20例，高钙血症 18例(其中高钙危象2例)，低磷血症10例。三项辅助检查(B 超、CT 和~(99m)Tc-MIBI 扫描)两项阳性90%。双侧甲状旁 腺探查3例，异位甲状旁腺经胸或经颈各1例，腔镜辅助甲状旁腺手术2例，其余均为一侧开放手术。术后3例严重 低钙血症，需要2～3个月的补钙调理。19例得到随访，术后半年血钙和 PTH 均正常。结论：遇骨质疏松、纤维囊性骨 瘤、不明原因骨折或变矮、反复肾结石、不明原因的 AKP 升高，需考虑 PHPT，需测定血钙与 PTH 作定性诊断。联合 B 超、CT 和核素扫描能协助定位。PHPT 手术是有效的治疗手段，微创化是趋势。要注重术前高钙危象和术后低钙血症 的处理。     

Role of citric acid in primary hyperparathyroidism with renal lithiasis

Summary Nephrolithiasis is presented in 18–40% of patients with primary hyperparathyroidism. Our work suggests that citrate, an inhibitor of calcium salts, could be involved in the presence of renal lithiasis because hyperparathyroid stone formers show less citrate elimination than nonstone formers.     

Prevalence and risk factors for primary hyperparathyroidism in hyperthyroid patients

BACKGROUND: Coexistence of hyperthyroidism and primary hyperparathyroidism may be more prevalent than previously recognized. We report 13 cases of concomitant occurrence of both diseases to estimate their combined prevalence and its factors. METHODS: Ninety-six unselected patients admitted for elective hyperthyroidism surgery were retrospectively included. Eighty-three patients were initially seen for hyperthyroidism with normocalcemia (group 1), and 13 patients were initially seen for hyperthyroidism with associated primary hyperparathyroidism (group 2). Patients' characteristics, examinations, and pathology reports were reviewed. Risk factors were identified using a logistic regression model. RESULTS: The prevalence of concomitant hyperparathyroidism was 13.5%. No patients manifested hypercalcemia in the absence of organic parathyroid disease. Eleven patients had a parathyroid adenoma, and two patients had parathyroid hyperplasia. Group 2 patients were older (median 61 vs 43 years, p = .006). Thyroid-stimulating hormone levels were more depressed in group 2 (median 0.01 vs 0.032 UI/L, p = .034). On multivariate analysis, age was the unique factor significantly different between groups (odds ratio, 1.05; 95% confidence interval, 1.008-1.098; p = .020). CONCLUSIONS: Hypercalcemia in patients with hyperthyroidism, particularly older patients, should warrant a thorough investigation for concomitant primary hyperparathyroidism that would dictate a combined thyroidectomy and parathyroidectomy.     

Sporadic primary hyperparathyroidism

Primary hyperparathyroidism (HPT1) is a common endocrine disorder, which is asymptomatic in 80% of cases. The diagnosis is ordinarily easily made, based on an inappropriately elevated parathormone level (PTH) in the face of hypercalcemia. In 85% of cases, HPT1 is due to hormone secretion from a single parathyroid gland (uniglandular disease) and the remaining patients have multiglandular disease. The best localization study is MIBI scintigraphy (methoxy isobutyl isonitrile) coupled with the results of a neck ultrasound exam (sensitivity >95%). Other investigations are reserved for patients with persistent or recurrent HPT1 post-surgery. Surgery is the only cure. The surgical approach may include a bilateral cervical exploration, a unilateral approach under local anesthesia, or focused minimally invasive (video-assisted or totally endoscopic) approaches. A decrease in PTH level measured intraoperatively of greater than 50% is predictive of cure in more than 97% of cases. Surgery is recommended even for moderate HPT1 and for very elderly patients because improvement in both the quality of life and bone density have been proven in these situations. The role of medical treatment is limited. Persistent or recurrent HPT1 requires a meticulous diagnostic approach and management in surgical centers with expertise. Persistent elevation of PTH postoperatively without hypercalcemia does not mandate further exploration. The prognosis of normocalcemic patients with elevated postoperative PTH levels remains uncertain.     

Quantitative ultrasound assessment of bone in patients with primary hyperparathyroidism

Quantitative ultrasound measurements were done in a group of 26 patients (4 males and 22 females, aged 55.4 ±14.2 years) with primary hyperparathyroidism, and the results were compared with bone mineral density (BMD) carried out at various skeletal sites. Speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness were measured with the Achilles ultrasound bone densitometer (Lunar Corp., Madison, WI). Mean ± SD values of SOS, BUA and stiffness in patients with primary hyperparathyroidism were 1522±38 m/seconds, 111±16 dB/MHz, and 80.4±19.8%, respectively. There were significant differences of mean T-score BUA values (-0.63±1.11) compared with corresponding T-score BMD values found at ultradistal (-1.85±1.73, P<0.01), proximal radius (-2.40±2.13, P<0.001), and total femoral (-1.60±1.32, P<0.001) sites. Correlation coefficients between both SOS and BUA values with BMD measurements at specific skeletal sites varied, but stiffness correlated moderately (0.6–0.9) with BMD. Our data strongly indicate that in patients with primary hyperparathyroidism, bone structure of some skeletal sites, as evaluated by BUA measurement, is compromised to a lesser extent than BMD. In this respect it is interesting to note the lack of significant differences (in terms of mean T-score values) in the comparison of two sites of mostly trabecular composition, that is, the lumbar level (-1.17±1.54) and the femoral Ward's triangle (-0.99±1.25). Our results seem to lend further support to the hypothesis that in primary hyperparathyroidism cancellous bone architecture might be preferentially maintained. Quantitative ultrasound techniques appear to complement, and could possibly substitute for, existing bone densitometry examinations.Submitted in part at the IIIrd European Congress of Endocrinology, Amsterdam, The Netherlands, July 17–22, 1994 and at the 16th Annual Meeting of the American Society for Bone and Mineral Research, Kansas City, MO, USA, September 9–13, 1994.     

Selective unilateral parathyroid exploration: an effective treatment for primary hyperparathyroidism

Background

Unilateral neck exploration (UNE) is a well-recognized approach in the treatment of primary hyperparathyroidism (PHP). The objective of this study was to review the success of an approach involving UNE guided by preoperative sestamibi (SM) scanning.

Methods

All data were gathered by retrospective chart review. All patients undergoing surgery for the treatment of primary hyperparathyroidism at a tertiary referral center over a 3-year period were included in the study cohort.

Results

Fifty-two of 80 patients (65%) had an SM scan consistent with a solitary adenoma and were eligible for a UNE, with 57.5% (46/80) undergoing a UNE. Seventy-seven of 80 (96.3%) patients were normocalcemic after initial neck exploration. UNE was curative in 50 of 52 (96.2%) UNE eligible patients and required less operative time than bilateral neck exploration (mean, 60 versus 87 minutes).

Conclusion

Selective unilateral neck exploration, guided by preoperative SM scanning, is an effective surgical approach for the management of primary hyperparathyroidism.     

Anesthesia and hyperparathyroidism

Key word  Anesthesia - primary hyperparathyroidism     

Computed axial tomography-MIBI image fusion for preoperative localization in primary hyperparathyroidism

BACKGROUND: An imaging-guided unilateral surgical approach in patients with primary hyperparathyroidism (HPTH) requires reliable preoperative localization procedures. Using present imaging techniques, 60% to 80% of patients with primary HPTH can be treated successfully with limited surgery. Thus, further improvement of diagnostic accuracy is required. Computed axial tomography (CAT)-MIBI image fusion was introduced as a new technique for localizing enlarged parathyroid glands. We describe the new method and present its first results. METHODS: Six consecutive patients with primary HPTH underwent CAT-MIBI image fusion for preoperative parathyroid localization. CAT and technetium-99m-sestamibi scan were performed separately. The patient's head and neck were fixed with the noninvasive Vogele-Bale-Hohner Head Holder (VBH HeadFIX; Medical Intelligence, Schwabmünchen, Germany) and the BodyFIX (Medical Intelligence) vacuum cushion. Radiographic and scintigraphic markers were mounted at the head holder and the patient. CAT and MIBI images were fused by overlaying radiographic markers using a commercial software and workstation. RESULTS: In 5 patients, localization and dimension of the solitary adenomas were exactly predicted. In 1 patient with multiglandular disease (3 enlarged glands), CAT-MIBI image fusion was not able to predict multiple gland involvement. However, in a retrospective analysis of the localization study, the other two enlarged parathyroid glands could be correctly identified regarding their site and size. CONCLUSIONS: First results of CAT-MIBI image fusion are promising. The new technique provides a higher image resolution and better delimitation of enlarged parathyroid glands and adjacent anatomic structures than conventional scintigraphic methods.     

Parathyromatosis as a cause of recurrence primary hyperparathyroidism: A case report

Introduction and importanceParathyromatosis is a rare cause of recurrent hyperparathyroidism. The main cause of this pathology is secondary implantation into the surrounding tissues of the damaged parathyroid gland (rough manipulation of the gland tissue) during the primary operation. Nowadays, parathyromatosis remain a difficult diagnostic and therapeutic task.Case presentationA 57-year-old woman 12 years ago underwent right inferior parathyroid adenomectomy. For the last 2 years, the patient began to worry about pain in large tubular bones, thoracic spine. In the biochemical analysis of the patient's blood, the serum ionized calcium level was increased - 1.56 mmol/l, parathyroid hormone - 144 pg/ml. Ultrasound scan of the neck showed the presence of two hypoechoic formations with dimensions of 24 × 12 × 6 mm and 14 × 9 × 8 mm behind the right lobe of the thyroid gland (the site of a previously operation).The patient underwent cervicotomy, removal of 3 fragments of the parathyromatosis tissue. According to a histological study, there fragments are presented by diffuse-nodular hyperplasia from dark main cells. Remission of primary hyperparathyroidism was achieved.Clinical discussionThis clinical case shows the need for differential diagnosis in recurrence primary hyperparathyroidism with parathyroid cancer, secondary hyperparathyroidism, parathyromatosis.ConclusionThe main method of treatment is the surgical removal of all foci of parathyromatosis. In the postoperative period, observation of such patients is required with laboratory and visual screening to exclude recurrence hyperparathyroidism.