Usefulness of diagnostic imaging in primary hyperparathyroidism

BACKGROUND: In patients with primary hyperparathyroidism, prevention of urinary stone recurrence can be achieved by surgical removal of the enlarged parathyroid gland. To ensure the efficacy of surgery for primary hyperparathyroidism, preoperative localization of the enlarged gland is important. In the present study, usefulness of diagnostic imaging for localization of the enlarged gland was investigated in primary hyperparathyroidism. METHODS: We retrospectively examined the findings of imaging studies and clinical records in 79 patients (97 glands) who underwent surgical treatment for primary hyperparathyroidism at Chiba University Hospital between 1976 and 2000. The detection rates of accurate localization were investigated for imaging techniques, such as ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), thallium-201 and technetium-99m pertechnetate (Tl-Tc) subtraction scintigraphy and 99mTc-methoxyisobutylisonitrile (MIBI) scintigraphy, and analysed in relation to the size and weight of the gland and pathological diagnosis. RESULTS: The detection rates by US, CT, MRI, Tl-Tc subtraction scintigraphy and MIBI scintigraphy were 70%, 67%, 73%, 38% and 78%, respectively. The overall detection rate changed from 50% to 88% before and after 1987. The detection rate of MIBI scintigraphy was superior to Tl-Tc subtraction scintigraphy. CONCLUSION: In primary hyperparathyroidism, improvement of accurate localization of an enlarged parathyroid gland was demonstrated along with recent advances in imaging techniques including MIBI scintigraphy.     

Color-Doppler in the imaging work-up of primary hyperparathyroidism.

Primary hyperparathyroidism (PHP) is a rare disease that must be suspected in all the cases of recurrent calcium nephrolithiasis, and that may be totally corrected by surgery. The imaging techniques permit to locate the hyperplastic gland or adenoma before intervention, but their usefulness in patients without a history of previous neck surgery is still debated. Several imaging techniques have been proposed with the aim of locating parathyroid hyperfunctioning glands, including high resolution sonography (US) with color-Doppler (CD), scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI). We report here a case of recurrent calcium oxalate nephrolithiasis sustained by PHP, which demonstrates how US coupled with CD and echocontrast enhancement is useful in the preoperative location of parathyroid glands. US is the first choice technique in the evaluation of PHP because it is less expensive and useful in detailing lesions of the neck when carried out by a skilled operator. CD should be regarded as a useful complement of US enhancing its sensitivity (80 vs 90%) especially in the cases of associated thyroid gland diseases. Tc-99m SESTAMIBI scintigraphy coupled with MRI is mandatory in high risk surgical patients, namely in those undergoing repeated neck surgery. In conclusion, considering that surgeon must explore all the four parathyroid glands (because of the possibility of multiple adenomas or hyperplasia) a well definite location of the adenomatous lesion may reduce the risks and the time of intervention, and allow the use of alternative procedures, such as videoscopic surgery. On this view and in terms of economy, only US and CD coupled with Tc-99 SESTAMIBI scintigraphy should be considered before surgery.     

Prospective comparison of radionuclide, computed tomographic, sonographic, and magnetic resonance localization of parathyroid tumors

The appropriate choice of imaging techniques to localize parathyroid tumors preoperatively remains controversial. We report the first prospective, blinded study to compare the efficacy of four imaging modalities in 100 patients with primary hyperparathyroidism (pHPT). Patients were examined by computer-assisted thallium 201/technetium 99m subtraction scintigraphy (TTS), computed tomography (CT), ultrasonography (US), and magnetic resonance (MR). Each study was performed and interpreted independently. Subsequent neck exploration and "curative" parathyroidectomy allowed correlation of surgical findings with imaging reports to score their accuracy. Overall sensitivities of the four imaging modalities were TTS, 73%, CT, 68%, US, 55%; and MR, 57%; with respective specificities of 94%, 92%, 95%, and 87%. Sensitivities for lesions located below the thyroid gland (thymic tongue and mediastinum) were TTS, 90%; CT, 46%; US, 44%; and MR, 50%; with respective specificities of 100%, 99%, 100%, and 94%. There was a significant increase in overall sensitivity when TTS and CT (90%, p less than 0.01) or TTS and US (85%, p less than 0.05) were used together; however, the combination of any three or even four imaging modalities did not increase sensitivity further. For small parathyroid tumors (less than or equal to 250 mg), no imaging technique had a sensitivity of more than 50%. None of the imaging studies accurately localized small hyperplastic parathyroid glands found in patients with multiple gland disease. Preoperative parathyroid imaging may not be indicated in pHPT patients undergoing first-time neck exploration because surgeons experienced in parathyroid surgery have a 93% to 96% cure rate.     

Preoperative Localization of Parathyroid Adenoma in Patients with Concomitant Thyroid Nodular Disease

We have previously demonstrated the role of high-resolution ultrasonography (US) in preoperative localization of parathyroid adenoma in patients with primary hyperparathyroidism (PHPT) and no thyroid abnormalities. The present study prospectively evaluated the possible additional value of ^99mTc-sestamibi (MIBI) in patients with PHPT and concomitant multinodular thyroid disease (MND). Patients with PHPT underwent US and MIBI scintigraphy prior to neck exploration. Imaging data were correlated with the site and pathology of the parathyroid tissue removed and were analyzed separately for patients with MND and those with a normal thyroid gland. Among 77 patients with a solitary parathyroid adenoma at surgery, 40 had concomitant MND, whereas 37 patients had no morphologic changes in the thyroid gland, on US or at surgery. Prior to surgery, MIBI scintigraphy depicted 58 of the 77 adenomas (75%) and US localized 51 (66%); the combined sensitivity was 87% (67/77). Among the 37 patients with no thyroid nodules, MIBI located 29 (78%) and US identified 30 (81%) of the adenomas; the combined sensitivity was 89%. In the 40 patients with MND, MIBI identified 29 adenomas (73%) and US localized only 53% (21/40); the combined sensitivity was 85%. Overall, the positive predictive value (PPV) of MIBI for detecting a solitary parathyroid adenoma was 94%, for US it was 88%, and with the two tests combined it was 97%. In patients with no thyroid abnormalities, the PPV of MIBI and US was 97%, but it decreased to 91% and 78%, respectively, in patients with MND. Two patients with false-positive findings on both MIBI and US had associated thyroid disease. Hence MIBI scintigraphy contributes to localization of a solitary parathyroid adenoma mainly in patients with concomitant MND. The combined MIBI and US modalities result in sparing these patients bilateral neck exploration.     

Usefulness of 99mTc-methoxy-isobutyl-isonitrile scintigraphy for preoperative localization of adenoma in primary hyperparathyroidism]

We evaluated the usefulness of 99mTc-methoxy-isobutyl-isonitrile (MIBI) dual phase scintigraphy for detecting hyperfunctioning parathyroid adenoma. We retrospectively reviewed 18 hyperparathyroid patients who received MIBI prior to neck exploration and compared the radiological findings of MIBI with ultrasonography (US) and magnetic resonance imaging (MRI). Fifteen patients were studied with MRI, and 17 patients were examined with US. All patients were found to have a solitary parathyroid adenoma histopathologically. MIBI correctly revealed the location of 17 adenomas among 18 confirmed tumors. In our series, there was one false-positive case that was found to have thyroid adenoma. The diagnostic sensitivity of MIBI MRI and US was 94.4%, 80% and 52.5%, respectively. The positive predictive value (PPV) was 94.4% for MIBI, 81.8% for MRI and 92.3% for US. We conclude that MIBI is useful and accurate for the preoperative localization of adenoma in primary hyperparathyroidism.     

Comparison of imaging methods for localization of parathyroid tumors.

Preoperative localization of parathyroid tumors by computed tomography (CT), thallium-201/technetium-99m pertechnetate subtraction scintigraphy (Tl-201/Tc-99m), ultrasonography (US), and magnetic resonance imaging (MRI) was compared in patients with hyperparathyroidism (HPT) to examine the characteristics of each method. A total of 87 patients with HPT were divided into two groups according to the time when they were examined. Patients in group I were examined before MRI had been introduced in our hospital, and a 2.5-MHz transducer probe was used for US. Those in group II were examined by MRI and US using a 7.5-MHz transducer probe. Group I included 45 patients (36 with primary hyperparathyroidism [PHPT] and 9 with secondary hyperparathyroidism [SHPT]), and group II included 42 patients (15 with PHPT and 27 with SHPT). In both PHPT and SHPT and SHPT of group I and PHPT of group II, there was no significant difference in detection rates between all diagnostic methods. In patients with SHPT in group II, the detection rate was significantly higher for CT than for Tl-201/Tc-99m and MRI (both p less than 0.01), and for US than for Tl-201/Tc-99m (p less than 0.01). In both groups I and II, the detection rate of each study method was significantly higher in patients with PHPT than in those with SHPT (all p less than 0.01). Compared with group I, the rate was significantly improved in group II, in both types of patients. Regarding the location of the parathyroid tumor, the detection rate of CT was significantly higher for upper parathyroid glands than for lower glands, whereas that of US and Tl-201/Tc-99m was significantly higher for lower glands. The detection rate sharply increased when the tumor weight reached 250 mg (CT, US) or 1,000 mg (Tl-201/Tc-99m, MRI).     

A case of secondary hyperparathyroidism with an ectopic intrathyroid gland successfully diagnosed and controlled by percutaneous ethanol injection therapy (PEIT)

Secondary hyperparathyroidism (II HPT) is a major complication in chronic dialysis patients, and percutaneous ethanol injection therapy (PEIT) has become a useful alternative treatment for II HPT. However, the existence of ectopic parathyroid glands is a major problem when conducting PEIT. Ectopic parathyroid gland accepts 10-35% of II HPT, and the missing glands cannot be detected consistently by any imaging techniques, including scintigraphy. Intrathyroid parathyroid gland is as rare as about 1% and recurrence of missing glands after parathyroidectomy (PTx) has been reported in some cases. We report here a 52-year-old female in whom an ectopic parathyroid gland was defected successfully and intact-PTH controlled by tentative PEIT. At the first examination, a left parathyroid adenoma and a right thyroid goiter were pointed out by ultrasonography, CT and scintigraphy. PEIT was applied twice to the left parathyroid adenoma, but intact-PTH was not decreased. Ultrasonography, CT, 201Tl-99mTc subtraction scintigraphy and fine needle aspiration biopsy (FNAB) were performed again to search for the existence of ectopic glands. The results suggested that the right intrathyroid tumor was an ectopic parathyroid gland. Consequently, tentative PEIT was applied to the right intrathyroid tumor, and successful control of intact-PTH and serum Ca was eventually achieved. To our knowledge, this is the first reported case of secondary hyperparathyroidism with an ectopic intrathyroid gland that was successfully controlled by PEIT. In this case, it was suggested that tentative PEIT of intrathyroid tumor was a useful method for detecting an ectopic parathyroid gland.     

High Success Rate of Parathyroid Reoperation may be Achieved with Improved Localization Diagnosis

Introduction Because of the difficulty of reoperative parathyroid surgery, preoperative imaging studies have been increasingly adopted. We report the use of consistently applied localization diagnosis to yield high success rates in parathyroid reoperations. Methods Parathyroid reoperation was performed after previous parathyroid surgery in 144 patients with nonmalignant hyperparathyroidism (HPT) between 1962 and 2007. From the year 2000, 46 patients who underwent parathyroid reoperation and 14 patients who were subjected to thyroid surgery before primary parathyroid operation were investigated with sestamibi scintigraphy (MIBI), ¹¹C-methionine PET/CT (met-PET), surgeon-performed ultrasound (US), US-guided fine-needle aspiration biopsy (US-FNA), and selective venous sampling (SVS) with rapid PTH (Q-PTH) analyses. When imaging was considered adequate, additional studies were generally not obtained. Results Reversal of hypercalcemia was achieved by reoperation in 134 of 144 (93%) of all patients with previous parathyroid surgery. In patients operated from year 2000, MIBI had 90% sensitivity and 88% predictive value, met-PET 79% sensitivity and 87% predictive value, and US 72% sensitivity and 93% predictive value. SVS with Q-PTH analyses provided accurate localization or regionalization in 11 of 11 recently selected patients. Q-PTH analyses in fine-needle aspirations verified parathyroid origin of excised specimens, and intraoperative Q-PTH helped decide when operations could be terminated. In patients subjected to the algorithm of imaging procedures, reversal of hypercalcemia and apparent cure was obtained after the reoperation in 45 of 46 patients with previous parathyroid surgery, implying a success rate of 98%, and in all patients with previous thyroid surgery. Conclusions Reoperative parathyroid surgery is challenging. Results can be improved by consistently applied sensitive methods of preoperative imaging, and reoperative procedures may then achieve nearly the same success rates as primary operations.     

Fifteen years experience in the surgical treatment of primary hyperparathyroidism

We measured the efficacy of preoperative localization techniques and results of parathyroidectomy in patients with primary hyperparathyroidism (HPT). From 1986 to 2001, 92 patients were treated with primary HPT. Preoperative localization technique was used in all patients (US n = 85, Tc-99m-sestamibi/Tc-99m-pertechnetate subtraction scintigraphy n = 67, CT n = 18, MRI n = 14) to visualize the abnormal parathyroids. Results of localization studies were compared with surgical and pathological findings. Bilateral neck exploration was carried out in each patient for the identification of all parathyroid glands. If parathyroid adenoma was diagnosed, exstirpation of the abnormal parathyroid was performed. If diffuse hyperplasia was diagnosed, subtotal parathyroidectomy (3 1/2) was performed. The overall sensitivity was 94% for scintigraphy, 74% for US, 67% for CT and 50% for MRI. The PPV was 97% for scintigraphy, 92% for US, 100% for CT and for MRI. At surgery 66 patients had single adenomas and 3 patients had double adenomas. Diffuse hyperplasia was diagnosed in 21 and parathyroid carcinoma was found in 2 patients. Persistent HPT was noted in 1 patient. Recurrent HTP occurred 4 times. After a second operation their HPT disappeared. In conclusion, the sensitivity of Technetium-99m-sestambi and Technetium-99m-pertechnetate subtraction scanning was significantly superior compared to other localization methods. The use of these sensitive preoperative technique can improve the success rate, and decrease the incidence of persistent and recurrent HPT.     

Optimizing preoperative imaging in primary hyperparathyroidism

Background Scintigraphy of the hyperfunctioning parathyroid glands using technetium 99m (^99mTc)-methoxyisobutylisonitrile (^99mTc-MIBI) is an established and highly sensitive preoperative localization tool whose importance has been further increased by advances in minimally invasive surgery .The goal of the present prospective study was to determine the benefit of optimized imaging in a consistent patient population.Methods Eighty-four patients with first presentations of primary hyperparathyroidism were investigated with ^99mTc-MIBI scintigraphy, thyroid scintigraphy, and cervical ultrasonography. The evaluation algorithm consisted of (a) evaluation of the planar images alone, (b) additional evaluation of single-photon emission computed tomography (SPECT), (c) additional evaluation of thyroid gland scintigraphy, and (d) additional evaluation of ultrasound. All patients subsequently underwent parathyroidectomy. The intraoperative and the histologic findings were correlated with the results of the scintigraphic imaging.Results The sensitivity of planar parathyroid scintigraphy was 74% and could be increased to 91% by the additional investigations. The difference was statistically significant (p<0.05). At the same time, a small increase in specificity from 96% to 99% was seen.Conclusions Prior to minimally invasive treatment of hyperparathyroidism, we recommend combined localization studies consisting of sequential ^99mTc-MIBI scintigraphy, additional SPECT plus thyroid gland scintigraphy, plus high-resolution cervical ultrasonography.     

Primärer Hyperparathyreoidismus

AIM: In a retrospective study, the sensitivity of parathyroid scintigraphy and ultrasound was investigated in patients with primary hyperparathyroidism (HPT) with prior histories of surgery of the thyroid or parathyroid (unsuccessful or recidive). METHODS: Preoperative ultrasound and parathyroid scintigraphy were performed on 65 patients who had had successful surgery and on 12 who had had unsuccessful surgery. The scintigraphy was carried out using a combined double phase/double nuclide technique with 300-600 MBq 99mTc-sestamibi for parathyroid imaging and 80-100 MBq 99mTc-pertechnetate for thyroid imaging. RESULTS: The sensitivity of parathyroid scintigraphy was 86% in patients with normal thyroid glands, 77% in those with recurrent goiter, and 62% in those with recurrent or persistent HPT. The ultrasound sensitivity was 86%, 50%, and 57% respectively. CONCLUSION: The sensitivity of parathyroid scintigraphy and ultrasound decreases considerably after surgery. That of parathyroid scintigraphy lay significantly below results published to date. However, parathyroid scintigraphy should be performed precisely in these cases, because the number of alternative parathyroid imaging methods aside from ultrasound are limited.     

Preoperative localization of supernumerary and ectopic parathyroid glands in patients with secondary hyperparathyroidism

The undetectable supernumerary and ectopic parathyroid glands have a high risk of persistent and recurrent hyperparathyroidism, especially in the patients with secondary hyperparathyroidism. Preoperative image diagnosis, CT scan, echogram and 201T1C1 scintigram were very useful for detecting supernumerary and ectopic parathyroid glands in our 132 patients who underwent parathyroidectomy for secondary hyperparathyroidism. Among these methods the scintigraphy showed the highest detection rate of the glands in the thymic tongue and in the upper mediastinum. CT scan showed the best detection rate of the glands located in the thyroid gland and those located between the thyroid gland and trachea. The echography was useful in detecting the glands in the thyroid gland, but could not offer easy visualization those located in the mediastinum. Even the ectopic parathyroid glands, weighing more than 500 mg were identifiable at about 90% when all the methods were applied routinely. In our experience, four patients had a supernumerary gland which was detected by the preoperative image diagnostic procedures at the initial surgery. One patient had a supernumerary gland in the mediastinum which was detected by image diagnosis after the initial operation and was removed at reoperation.     

Parathyroid imaging: comparison of 201Tl-99mTc subtraction scintigraphy, computed tomography and ultrasonography

From 1982 to 1985, twenty-nine patients with suspected hyperparathyroidism were examined using 201Tl-99mTc subtraction scintigraphy (Tl-Tc), computed tomography (CT) and ultrasonography (US). For diagnosing neoplasm (adenoma or cancer), the sensitivities of the three procedures were 80 per cent or more, with no statistically significant differences. For diagnosing hyperplasia of the parathyroid glands, CT scan had the highest sensitivity (47 per cent). The most frequent source of error was minimally enlarged glands, weighing less than 500 mg. The second highest source of error was thyroid nodules, such as adenomatous goiter or cancer. Serum calcium and c-PTH levels were significantly higher in those with a parathyroid neoplasm than in those with hyperplasia (p less than 0.01, p less than 0.05, respectively). We concluded that hyperplasia is less easy to detect than neoplasm, and CT scan is superior to Tl-Tc or US scan for localizing hyperplasia.     

Parathyroid imaging: Comparison of201Tl-99mTc subtraction scintigraphy,computed tomography and ultrasonography

From 1982 to 1985, twenty-nine patients with suspected hyperparathyroidism were examined using²⁰¹Tl-^99mTc subtraction scintigraphy (Tl-Tc), computed tomography (CT) and ultrasonography (US). For diagnosing neoplasm (adenoma or cancer), the sensitivities of the three procedures were 80 per cent or more, with no statistically significant differences. For diagnosing hyperplasia of the parathyroid glands, CT scan had the highest sensitivity (47 per cent). The most frequent source of error was minimally enlarged glands, weighing less than 500 mg. The second highest source of error was thyroid nodules, such as adenomatous goiter or cancer. Serum calcium and c-PTH levels were significantly higher in those with a parathyroid neoplasm than in those with hyperplasia (p<0.01, p<0.05, respectively). We concluded that hyperplasia is less easy to detect than neoplasm, and CT scan is superior to Tl-Tc or US scan for localizing hyperplasia.     

Limited role of meta-iodobenzylguanidine scintigraphy in imaging phaeochromocytoma in patients with multiple endocrine neoplasia type II.

OBJECTIVE: To compare diagnostic applicability of combined computed tomography (CT) and magnetic resonance imaging (MRI), with that of meta-iodobenzylguanidine (MIBG) scintigraphy in the preoperative localisation of MEN II related phaeochromocytoma. DESIGN: Retrospective study SETTING: University hospital, The Netherlands. MATERIALS: 17 patients with MEN II patients (33 adrenal glands) who were operated on for phaeochromocytoma. MIBG scintigraphy, CT and MRI were used to localize phaeochromocytoma. Histopathologically, an adrenomedullary lesion more than 1 cm in size was classified as a phaeochromocytoma. MAIN OUTCOME MEASURES: Sensitivity, specificity, and diagnostic accuracy of combined CT and MRI and MIBG scintigraphy, compared with histopathological findings. RESULTS: Sensitivity of combined CT and MRI (27 adrenal glands) was 87%, with a specificity of 100% and a diagnostic accuracy of 89%. MIBG scintigraphy (31 adrenal glands) had a sensitivity of 92%, a specificity of only 17%, and a diagnostic accuracy of 77%. CONCLUSION: If unilateral adrenalectomy is done when only one adrenal gland contains a phaeochromocytoma, then MRI should be the method of choice for localising MEN type II related phaeochromocytoma. MIBG scintigraphy can be restricted to those patients in whom MRI does not show a tumour.     

18F-fluorocholine PET/CT and conventional imaging in primary hyperparathyroidism

PurposeThe purpose of this study was to assess the diagnostic capabilities of preoperative conventional imaging (^99mTc-MIBI scintigraphy, cervical ultrasonography [CUS]) and ¹⁸F-fluorocholine PET/CT (FCH PET/CT) in the detection of hyperfunctioning parathyroid gland in patients with primary hyperparathyroidism (PHPT) used alone or as a single imaging set.Materials and methodsA total of 51 consecutive patients (6 men, 45 women; mean age, 62 ± 11.6 [SD] years; age range: 28–86 years) with biochemically confirmed PHPT who underwent CUS, single-tracer dual phase ^99mTc-MIBI scintigraphy and FCH PET/CT were retrospectively included. ^99mTc-MIBI scintigraphy were performed immediately after CUS and interpreted by the same operators. FCH PET/CT examinations were interpreted independently by two nuclear medicine physicians. An additional reading session integrating the three imaging modalities read in consensus as a combined imaging set was performed.ResultsAt surgery, 74 lesions were removed (32 parathyroid adenomas, 38 parathyroid hyperplasia and 4 subnormal glands). Thirty-six patients (71%) had single-gland disease and 15 patients (29%) had multiglandular disease at histopathological analysis. On a patient basis, sensitivity and accuracy of FCH PET/CT, CUS and ^99mTc-MIBI scintigraphy for the detection of abnormal parathyroid glands were 76% (95% CI: 63–87%) and 76% (95% CI: 63–87%), 71% (95% CI: 56–83%) and 71% (95% CI: 56–83%), 33% (95% CI: 21–48%) and 33% (95% CI: 21–48%), respectively. The sensitivity of the combined imaging set was 94% (95% CI: 84–99%) and greater than the sensitivity of each individual imaging technique (P ≤ 0.001 for all).ConclusionOur results suggest that CUS, ^99mTc-MIBI scintigraphy and FCH PET/CT interpreted as a single imaging set could be the ideal practice to precisely localize parathyroid lesion in patients with PHPT before surgery.     

Significant Clinical Differences in Primary Hyperparathyroidism Between Patients with and Those Without Concomitant Thyroid Disease

Purpose We evaluated the differences in diagnosis and treatment for primary hyperparathyroidism (pHPT) in patients with and those without concomitant thyroid disease.Methods One hundred and ten patients with pHPT underwent parathyroid localization and thyroid examination by ultrasonography (US) and sestamibi scintigraphy (MIBI). The clinical and biochemical findings, parathyroid localization, and operations performed were compared in 49 patients without thyroid disease and 61 patients with thyroid disease.Results Asymptomatic hypercalcemia was significantly more prevalent in patients with concomitant thyroid disease (88.5%) than in those without thyroid disease (49.0%) (P < 0.01). The mean serum calcium was significantly higher and the inorganic phosphate level was significantly lower in patients without concomitant thyroid disease than in those with concomitant thyroid disease (P < 0.05, P < 0.01, respectively). The pathologic parathyroid gland was identified significantly more often in patients without concomitant thyroid disease than in those with concomitant thyroid disease both by US and MIBI (P < 0.05). Unilateral exploration was performed more often in patients without thyroid disease than in those with thyroid disease (P < 0.01).Conclusion Primary hyperparathyroidism was diagnosed at an earlier stage in patients with concomitant thyroid disease. Thyroid disease concomitant with pHPT influenced parathyroid localization as well as the indication for minimally invasive parathyroidectomy.     

Factores que condicionan la sensibilidad de la ecografía y la gammagrafía en la localización del adenoma paratiroideo

IntroductionThe treatment of choice for primary hyperparathyroidism (PHPT) when there is proper preoperative localization of the adenoma is minimally invasive parathyroidectomy. However, imaging techniques are not always able to provide the exact location. The objective is to identify potential factors that might influence the sensitivity and concordance of ultrasound (US) and 99mTc-methoxy-isonitrile parathyroid scintigraphy (MIBI-PS) and the actual location of the adenoma.MethodsWe reviewed the data of patients who underwent parathyroidectomies for PHPT. All patients had undergone ultrasound and 99mTc-MIBI scintigraphy as a preoperative location study. Multiple endocrine neoplasms, other hyperplasias and non-cervical ectopic adenomas were excluded. The sensitivity, PPV and concordance have been estimated for the location of the gland in both tests compared with the intraoperative location, using a multivariable analysis of the factors that might influence their localization capacity.Results139 patients (82% women) have been analysed. The US sensitivity was 56.7%, concordance (Kappa index) 0.387 and PPV 96.3%. The MIBI-PS sensitivity was 81.6%, the concordance (Kappa index) 0.669 and the PPV 97.4%. The factor that improved localization of the glands by US in the multivariable analysis was the absence of a concomitant thyroid pathology. The factor that improved the MIBI-PS results was a gland weight greater than 600 mg.ConclusionsUS sensitivity improves when there is no concomitant thyroid pathology. MIBI-PS sensitivity improves when the gland weight is greater than 600 mg.     

Detection of parathyroid adenoma in patients with primary hyperparathyroidism: the use of office-based ultrasound in preoperative localization

BACKGROUND: The purpose of this investigation is to show that preoperative localization of the parathyroid gland using office-based ultrasound (US) and Tc-99m sestamibi scan is superior to all other approaches in detecting a parathyroid adenoma. METHODS: We performed a retrospective analysis of 43 patients who underwent parathyroidectomy for primary hyperparathyroidism. All patients underwent office-based US and sestamibi scintigraphy. Upon completion of the localization studies, a plan for focused or full operation was determined. RESULTS: In 42 of 43 patients, office-based US performed by a surgeon and sestamibi scintigraphy successfully detected the location of a parathyroid abnormality (42/43 cases, sensitivity = 98%, P < .05 =.0001). Office-based US localized the abnormal gland to the specific side (right/left) in 36 of 43 cases (84%). Sestamibi alone localized to the specific side in 29 of 43 cases (67%) for a statistically significant difference (P = .03). US localized the abnormal gland to the specific quadrant (34/43 cases [79%] sensitivity versus 23/43 cases [53%] sensitivity using sestamibi scan alone to localize to the specific quadrant, P = .03). CONCLUSION: It is clear that the combined modalities of office-based US and sestamibi scintigraphy in preoperative localization have a high success rate and should be considered in parathyroid surgery.     

Intrathyroid Parathyroid Adenoma in Primary Hyperparathyroidism: Can It Be Predicted Preoperatively?

Introduction The role of cervical ultrasonography (US)-guided surgery for intrathyroid parathyroid adenoma in primary hyperparathyroidism is rarely reported. The aim of this study was to elucidate the role of cervical US in identifying this entity. Methods From 1996 to 2003, cervical explorations were performed in 178 patients (mean age 57 years) with primary hyperparathyroidism. High-resolution cervical US was performed in all of the patients. Patients’ characteristics were reviewed to identify predictive factors for intrathyroid adenoma. Results Cervical US identified abnormal parathyroid glands in 163 of 178 patients, with a positive predictive value (PPV) of 100%. Six patients (3.4%) were found to have intrathyroid parathyroid adenomas (two in the superior parathyroid and four in the inferior parathyroid). Cervical US predicted this anomaly in four of six patients (67%) in whom the thyroid gland was not nodular and allowed total enucleation of the adenoma to be performed in three and subtotal thyroid loboisthmectomy in three; these operations were performed uneventfully and rapidly. The PPV in this anomaly was 80%. Thirteen patients required postoperative calcium supplementation for 2 to 4 months, and all were normocalcemic at the time of the last clinic visit, with follow-up varying from 12 to 96 months. On multivariable analysis, no factor predicted intrathyroid localization of parathyroid adenoma. Conclusions The PPV of high-resolution cervical US for identifying an abnormal parathyroid gland was 100% in this series. It was 80% for predicting intrathyroid localization of the adenoma. This method allows us to shorten the operating time by guiding the exploration immediately toward the thyroid gland.