Serendipitous detection of metastatic thyroid cancer during I-123 Tc-99m sestamibi dual parathyroid imaging

Dual isotope parathyroid imaging performed on a 47-year-old man with known papillary thyroid cancer and biochemical hyperparathyroidism showed residual concentration of sestamibi consistent with a right inferior parathyroid adenoma. Subsequent thyroidectomy and parathyroidectomy was performed. Histology revealed a left superior parathyroid adenoma and normal right inferior parathyroid gland. Right inferior parathyroid adenoma on scintigraphy was, in fact, a cervical lymph node metastasis from the papillary thyroid carcinoma.     

Papillary thyroid carcinoma associated with parathyroid adenoma detected by pertechnetate-MIBI subtraction scintigraphy

Two cases of papillary thyroid carcinoma coexisting with a parathyroid adenoma are reported. A double-tracer pertechnetate-MIBI subtraction scan combined with neck ultrasound correctly visualized the site of the parathyroid adenoma despite the presence of thyroid nodule(s) located in the opposite thyroid lobe in one case and in both thyroid lobes in the other case. In both patients, the papillary thyroid carcinoma was cold with Tc-99m pertechnetate and hot with MIBI. Total thyroidectomy and parathyroidectomy of a solitary parathyroid adenoma were performed in both patients. Pertechnetate-MIBI subtraction scanning associated with neck ultrasound appears to be a useful imaging technique to detect parathyroid adenoma before operation in patients with concomitant thyroid nodular disease. A MIBI-hot and Tc-99m pertechnetate-cold thyroid nodule can indicate the possible presence of a malignant lesion.     

Co-existent parathyroid adenoma and thyroid carcinoma. Nonspecificity of dual tracer parathyroid imaging for parathyroid lesions

Dual tracer parathyroid imaging (DTPI) using Tc-99m and TI-201 has a reported sensitivity of 92% for the detection of parathyroid adenomas. A patient with biopsy-proven parathyroid adenoma as well as papillary thyroid carcinoma is presented. To date, this is the first such case ever to be reported and implies that DTPI, although a sensitive diagnostic modality for parathyroid adenoma detection, is not specific. The diagnosis of primary hyperparathyroidism has recently been established more frequently than in the past due to detection of elevated serum calcium levels on routine blood samples, relatively sensitive parathormone (PTH) assays, and noninvasive imaging modalities such as nuclear medicine, CT scanning, and ultrasonography. At our institution, we have successfully detected the location of parathyroid adenomas in many cases, using the dual tracer method with TI-201 and Tc-99m, confirmed at surgery. We present a case of primary hyperparathyroidism in which two distinct lesions were detected by nuclear imaging: one lesion was proven at surgery to be a parathyroid adenoma, while the other represented thyroid carcinoma.     

Hyperparathyroidism with a functioning parathyroid cyst

A rare case of primary hyperparathyroidism with a functioning parathyroid cyst in whom Tc-99m MIBI scintigraphy failed to detect a parathyroid tumor is presented. A 62-year-old woman with primary hyperparathyroidism was referred for Tc-99m MIBI imaging to investigate a parathyroid adenoma. Plasma levels of intact parathyroid hormone were elevated to 2250 pg/mL. Neck ultrasonography revealed a cystic lesion measured 30 x 42 x 35 mm on the right inferior side of the thyroid gland. The cystic lesion was successfully removed at surgery. Pathologic diagnosis revealed a benign parathyroid cyst. The cyst contained clear fluid, and was lined by 1 layer of cuboidal epithelial cells. Her postoperative course was uneventful and plasma levels of intact parathyroid hormone normalized after operation.     

Dual Pathologies of Parathyroid Adenoma and Papillary Thyroid Cancer on Fluorocholine and Fluorodeoxyglucose PET/CT

¹⁸F-Fluorocholine (FCH) PET/CT is evolving as a functional imaging modality for the preoperative imaging of abnormal parathyroid tissue(s) helping to localize eutopic and ectopic parathyroid tissue and limit the extent of surgery. FCH PET/CT may show incidental uptake in various thyroid lesions necessitating further evaluation, whereas the role of ¹⁸F-fluorodeoxyglucose (FDG) PET/CT in the detection of incidental thyroid nodules is well documented. The case of a middle-aged woman with dual pathology of parathyroid adenoma and papillary thyroid cancer detected on FCH and FDG PET/CT is presented.     

Unusual location of a parathyroid adenoma: the carotid sheath

We report the imaging features of an occult parathyroid adenoma with unusual location in the carotid sheath. Our patient presented with primary hyperparathyroidism. Following negative neck ultrasound and scintigraphy, exploratory neck dissection with partial thyroidectomy was performed twice over a 2 day period without biological response. Cervical and mediastinal CT and MRI were performed with no result. Digital angiography showed a tumoral blush supplied by the left inferior thyroid artery and located in close contact with the carotid artery. Venous sampling of the neck confirmed the left location of the adenoma and a third surgical intervention found the adenoma embedded in the left carotid sheath. This is an unusual case of parathyroid adenoma that necessitated the use of several imaging techniques.     

Association of parathyroid adenoma and autonomous nodule of the thyroid. Diagnostic efficacy of 201thallium-99mtechnetium scintigraphy

The thallium-technetium subtraction technique, proposed originally by Ferlin and co-workers, is now widely used to localize parathyroid adenoma. We report here the case of a hypercalcemic woman, referred to our ward with the biologically assessed diagnosis of primary hyperparathyroidism. Thallium-technetium subtraction scintigraphy not only successfully localized the parathyroid adenoma but also revealed the existence of an autonomous nodule of the thyroid, which was not suspected. It has previously been shown that this method can localize parathyroid adenoma in cases of cold thyroid nodule. This report shows that this is also true in the case of hot thyroid nodule. No observations of concomitant parathyroid adenoma and autonomous nodule of the thyroid have been reported (at least during the two past decades). Is this association casual or has it never been noticed? Further examinations can be performed with thallium when a hot thyroid nodule is found in a hypercalcemic patient.     

Gray-scale echographic visualization of a parathyroid adenoma

A large parathyroid adenoma and a smaller follicular thyroid adenoma were visualized with a combination of radionuclide imaging and gray-scale ultrasound in a patient with primary hyperparathyroidism.     

99Tcm sestamibi--a new agent for parathyroid imaging

Parathyroid imaging using 99Tcm sestamibi has been carried out prior to surgery in five patients with hyperparathyroidism and the results compared with a standard preoperative localization technique using 201Tl (thallous chloride). The 99Tcm sestamibi correctly localized all abnormal glands and showed higher parathyroid to thyroid uptake in three of four parathyroid adenomas. Both agents showed localization in a thyroid adenoma. The higher uptake of sestambi and better imaging properties of its 99Tcm radiolabel means that the agent may replace thallium for routine preoperative parathyroid localization.     

Successful localisation of parathyroid adenomata by thallium-201 and technetium-99m subtraction scintigraphy: description of an improved technique

An improved method for parathyroid scanning using thallium-201 and technetium-99m subtraction imaging is described. The technique successfully localised ten of eleven parathyroid adenomas confirmed at neck exploration. Two false-positive studies were encountered in patients with no adenoma at operation, probably due to thyroid nodules. The technique was less successful in identifying diffusely hyperplastic parathyroid glands and was negative in a single patient with recurrent, functional parathyroid carcinoma.     

Association of parathyroid adenoma and autonomous nodule of the thyroid. Diagnostic efficacy of 201thallium-99mtechnetium scintigraphy

The thallium-technetium subtraction technique, proposed originally by Ferlin and co-workers, is now widely used to localize parathyroid adenoma. We report here the case of a hypercalcemic woman, referred to our ward with the biologically assessed diagnosis of primary hyperparathyroidism. Thallium-technetium subtraction scintigraphy not only successfully localized the parathyroid adenoma but also revealed the existence of an autonomous nodule of the thyroid, which was not suspected. It has previously been shown that this method can localize parathyroid adenoma in cases of cold thyroid nodule. This report shows that this is also true in the case of hot thyroid nodule. No observations of concomitant parathyroid adenoma and autonomous nodule of the thyroid have been reported (at least during the two past decades). Is this association casual or has it never been noticed? Further examinations can be performed with thallium when a hot thyroid nodule is found in a hypercalcemic patient.     

无症状甲状旁腺腺瘤合并甲状腺乳头状癌的主要特征

 目的 总结无症状甲状旁腺腺瘤(parathyroid adenoma,PA)合并甲状腺乳头状癌(pillary thyroid carcinoma,PTC)的主要特征,以提高两病并存时的诊断水平。方法 回顾分析新疆医科大学附属肿瘤医院2005-01至2014-12诊断的12例无症状PA合并PTC患者一般资料及病理组织形态学特点。结果 12例中,2例血清钙和血清甲状旁腺素(parathyroid hormone ,PTH)增高、 血清磷降低。PA镜下实质细胞由主细胞、嗜酸性细胞混合组成。瘤细胞排列成巢状、片状或囊状,核稍大,偶见核分裂象。肿瘤均包膜完整,未见坏死。免疫组化表型所有 12 例PA 病例CK19、PTH、嗜铬粒素A(CgA)均为阳性;甲状腺转录因子-1(TTF-1),甲状腺球蛋白(TG),降钙素均为阴性,Ki-67阳性指数 ＜3%。结论 无症状PA合并PTC临床上比较少见,术前应仔细检查,排除两病共存的情况,避免遗漏。术中有必要行冷冻病理切片检查,而且还应与甲状旁腺癌、PTC等肿瘤鉴别。     

MRI对甲状旁腺腺瘤的诊断价值

目的探讨甲状旁腺腺瘤的MRI表现，结合文献评估MR对甲状旁腺腺瘤的定性、定位诊断价值。方法对临床及手术病理证实的5例甲状旁腺腺瘤患者术前均行MR检查，男3例，女2例，年龄21～39岁。所用设备为SIEMENS sonata1．5T超导型磁共振成像系统。结果5例腺瘤均位于甲状腺下极食管-气管隐窝区，4例表现为T1WI稍低信号，T2WI高信号，1例信号不均匀，病理检查示部分坏死。腺瘤边缘清晰，大小1．2cm×1．0cm×1．6cm-2．2cm×3．1cm×4．1cm。结论MRI是诊断甲状旁腺腺瘤的有效影像方法，可以准确显示腺瘤的大小、形态、部位及与周围组织结构的毗邻关系。对甲状旁腺腺瘤的诊断和临床治疗方式的选择具有重要意义。     

Dual-phase 99mTc-sestamibi imaging: its utility in parathyroid hyperplasia and use of immediate/delayed image ratios to improve diagnosis of hyperparathyroidism

OBJECTIVE: Dual-phase (99m)Tc-sestamibi (methoxyisobutylisonitrile [MIBI]) imaging is the technique of choice for hyperparathyroidism (HPT), especially for localizing parathyroid adenomas. Prior studies have shown its utility for detecting hyperplasia is equivocal, but we believe this is not true. We attempted to quantitate the region-of-interest counts per pixel between immediate images and delayed images (I/D ratio) and use this ratio to distinguish normal parathyroid versus hyperplasia versus adenoma. METHOD: Anterior pinhole and upper thorax images with a low-energy, high-resolution collimator at 20 min and 2 h after (99m)Tc-MIBI injection were obtained on 54 subjects. The results were analyzed retrospectively as hyperplasia, adenoma, or normal parathyroid by the persistence of activity in 2 or more foci, a solitary focus, or no activity on the delayed images. These interpretations were compared with pathology when available. I/D ratios were computed for all scans, and mean ratios were calculated for each type of pathology (normal parathyroid, hyperplasia, and adenoma). The resulting ratios were analyzed with a t test to determine significant differences between the ratios. RESULTS: Sensitivity and specificity were 96% and 88%, respectively, for parathyroid hyperplasia. Mean I/D ratios were 2.26 +/- 0.68, 2.80 +/- 0.95, and 3.10 +/- 0.77 for subjects with hyperplasia, adenoma, and normal parathyroid, respectively (hyperplasia vs. normal, P = 0.020; adenoma vs. normal, P = 0.381; hyperplasia vs. adenoma, P = 0.033). CONCLUSION: Dual-phase (99m)Tc-MIBI imaging is more sensitive and specific for parathyroid hyperplasia than reported previously, supporting its use to localize hyperplastic glands preoperatively and to help guide resection. A thyroid ratio between immediate and delayed images will aid in distinguishing hyperplasia from normal parathyroid in uncertain cases.     

Detection and localization of parathyroid adenomas in patients with hyperparathyroidism using a single radionuclide imaging procedure with technetium-99m-sestamibi (double-phase study)

Dual radionuclide imaging using a combination of 201Tl with either 99mTcO4- or 123I is recognized as a useful procedure in the preoperative localization of parathyroid adenomas. Recently, 99mTc-sestamibi (MIBI) has been introduced for myocardial perfusion imaging as an alternative to 201Tl. The purpose of this prospective study was to evaluate parathyroid scan using early and late imaging following MIBI injection. Twenty-three patients (21 F, 2 M, mean age: 57 yr) with a clinical and biologic diagnosis of hyperparathyroidism were submitted to a MIBI study prior to surgical exploration of the neck. Cervico-thoracic planar imaging (anterior view, 10 min/view) was performed at 15 min and at 2-3 hr after an intravenous injection of 20-25 mCi of MIBI. A positive MIBI scan for parathyroid adenoma was defined as an area of increased focal uptake which persisted on late imaging, contrary to the uptake in the normal thyroid tissue which progressively decreases over time (differential washout). Surgical exploration of the neck, performed between 1 day and 72 days (average: 16 days) after the MIBI study, showed a parathyroid adenoma in 21 patients and hyperplasia in two patients. MIBI scan correctly detected and localized 19/21 adenomas (90%). In conclusion, parathyroid imaging using a single radionuclide with MIBI (early and late study with differential washout analysis) is a promising procedure in the preoperative detection and localization of parathyroid adenomas in patients with primary hyperparathyroidism.     

Parathyroid imaging with pertechnetate plus perchlorate/MIBI subtraction scintigraphy: a fast and effective technique

We set up a modified technetium-99m (Tc-99m) pertechnetate/Tc-99m MIBI (Tc-MIBI) subtraction scintigraphy for parathyroid imaging by introducing the use of potassium perchlorate (KCLO4). Initially, the effect of KCLO4 on technetium thyroid wash-out was evaluated in five healthy volunteers: 40-minute dynamic studies of the thyroid were obtained 20 minutes after the injection of technetium 150 MBq (4 mCi), both in baseline conditions and after the oral administration of 400 mg KCLO4. After an average latency time of 10.5 minutes, KCLO4 administration resulted in fast and relevant technetium thyroid wash-out with a mean half-time of 16.2 minutes (the half-time was 142.8 minutes in baseline conditions), and a 40-minute reduction of thyroid activity of 78% (it was 14% in baseline conditions). Based on these findings, a new Tc-MIBI subtraction procedure was established as follows: 1) 150 MBq technetium (4 mCi) injection; 2) 400 mg KCLO4 administered orally; 3) patient neck immobilization; 4) acquisition of a 5-minute technetium thyroid scan; 5) 500 MBq MIBI (13.5 mCi) injection; 6) acquisition of a sequence of seven MIBI images, each lasting 5 minutes; and 7) processing (image realignment when necessary, background subtraction, normalization of MIBI images to the maximum pixel count of the technetium image, and subtraction of the technetium image from the MIBI images). In addition, high-resolution neck ultrasound (US) was performed in all cases on the same day as the scintigraphic evaluation. Eighteen consecutive patients with primary hyperparathyroidism were enrolled in the study. Tc-MIBI scintigraphy revealed a single adenoma in all cases and US showed this finding in 15 of 18 cases (83.3%). Furthermore, in three patients, a thyroid nodule associated with hyperparathyroidism was detected by technetium thyroid scans and neck US. In all patients, the parathyroid adenoma was easily identified on both the 20- to 40-minute MIBI and subtracted (MIBI-Tc) images. Regarding the scintigraphic parameters, no difference was found between parathyroid adenomas located in the region of the thyroid bed or in ectopic sites and in parathyroid adenomas with a retrothyroid location. Surgical findings confirmed the presence of a single parathyroid adenoma in all cases. In the three patients with a concomitant thyroid nodule, thyroid lobectomy was performed. These preliminary data suggest that 1) double-tracer subtraction scintigraphy, combined with neck US, appears to be the preferable preoperative imaging procedure in hyperparathyroidism patients with concomitant thyroid nodular disease, 2) in the Tc-MIBI parathyroid scan, the use of KCLO4 results in a rapid and relevant technetium thyroid clearance, improving the quality of MIBI images and making the visualization of parathyroid adenomas, particularly those located behind the thyroid gland, easier.     

Importance of radio-guided minimally invasive parathyroidectomy using hand-held gamma probe and low (99m)Tc-MIBI dose. Technical considerations and long-term clinical results.

AIM: (99m)Tc-MIBI radio-guided surgery results, obtained in a group of 141 patients with primary hyperparathyroidism (HPT), are reported. METHODS: All patients were preoperatively evaluated by a single day protocol based on double-tracer parathyroid scintigraphy and neck ultrasound, and then operated by the same surgical team. In 102 patients (72.3%) with a high scan/ultrasound probability of solitary parathyroid adenoma and normal thyroid gland, a minimally invasive radio-guided surgery was planned. In the other 39 patients (27.7%) with scan/ultrasound evidence of multi-glandular disease (n=8) or concomitant nodular goiter (n=31), the intraoperative gamma probe was used during a standard bilateral neck exploration. Intraoperative quick parathyroid hormone (PTH) levels were routinely measured. The minimally invasive radio-guided surgery technique we developed, consisted of: a) injection of a low 37 MBq (99m)Tc-MIBI dose in the operative theatre during anaesthesia induction, b) patient's neck scan with a hand-held gamma probe just before the surgical cut to localize the cutaneous projection of the parathyroid adenoma, c) intraoperative probe detection of the parathyroid adenoma and its removal through a small 2-2.5 cm skin incision. RESULTS: Minimally invasive radio-guided surgery was successfully performed in 99/102 patients (97.0%). The gamma probe was particularly useful in patients with an ectopic parathyroid adenoma in the upper mediastinum (n=11) or to the carotid bifurcation (n=1) or located deep in the neck (n=8). Minimally invasive radio-guided surgery was also obtained in 18/23 patients who had previously undergone thyroid/parathyroid surgery. The mean operative time for minimally invasive radio-guided surgery was 38 min. No major surgical complication was recorded. Conversion to bilateral neck exploration was required in only 3 cases because of intra-operative diagnosis of parathyroid carcinoma (n=2), and persistence of elevated quick PTH levels after removal of the preoperatively visualized parathyroid adenoma (n=1). Among patients treated by standard bilateral neck exploration, the gamma probe was useful in localizing a thymical enlarged parathyroid gland in 1 patient with multi-glandular disease, a parathyroid adenoma located deep in the neck in 4 patients with concomitant nodular goiter and an ectopic parathyroid adenoma to the carotid bifurcation in another. However, in some other patients with a parathyroid adenoma located near to the thyroid, it was difficult to intraoperatively distinguish the parathyroid adenoma from a MIBI avid thyroid nodule. CONCLUSION: It can be concluded that: (a) in primary HPT patients with high scan/ultrasound probability of solitary parathyroid adenoma and normal thyroid gland, the gamma probe appears to be an effective, rapid and safe technique to perform minimally invasive radio-guided surgery; b) a (99m)Tc-MIBI dose as low as 37 MBq appears to be adequate to successfully perform radio-guided surgery; c) the measurement of quick PTH is recommended during minimally invasive radio-guided surgery; d) minimally invasive radio-guided surgery can be performed also in HPT patients with previous parathyroid/thyroid surgery thus limiting surgical trauma; e) with the possible exception of parathyroid adenoma located in ectopic sites or deep in the neck, the gamma probe technique does not seem recommendable in HPT patients with concomitant nodular goiter.     

2009 EANM parathyroid guidelines

The present guidelines were issued by the Parathyroid Task Group of the European Association of Nuclear Medicine. The main focus was imaging of primary hyperparathyroidism. Dual-tracer and single-tracer parathyroid scintigraphy protocols were discussed as well as the various modalities of image acquisition. Primary hyperparathyroidism is an endocrine disorder with high prevalence, typically caused by a solitary parathyroid adenoma, less frequently (about 15%) by multiple parathyroid gland disease (MGD) and rarely (1%) by parathyroid carcinoma. Patients with MGD may have a double adenoma or hyperplasia of three or all four parathyroid glands. Conventional surgery has consisted in routine bilateral neck exploration. The current trend is toward minimally invasive surgery. In this new era, the success of targeted parathyroid surgery depends not only on an experienced surgeon, but also on a sensitive and accurate imaging technique. Recognizing MGD is the major challenge for pre-operative imaging, in order to not direct a patient towards inappropriate minimal surgery. Scintigraphy should also report on thyroid nodules that may cause confusion with a parathyroid adenoma or require concurrent surgical resection. The two main reasons for failed surgery are ectopic glands and undetected MGD. Imaging is mandatory before re-operation, and scintigraphy results should be confirmed with a second imaging technique (usually US for a neck focus, CT or MRI for a mediastinal focus). Hybrid SPECT/CT instruments should be most helpful in this setting. SPECT/CT has a major role for obtaining anatomical details on ectopic foci. However, its use as a routine procedure before target surgery is still investigational. Preliminary data suggest that SPECT/CT has lower sensitivity in the neck area compared to pinhole imaging. Additional radiation to the patient should also be considered. The guidelines also discuss aspects related to radio-guided surgery of hyperparathyroidism and imaging of chronic kidney disease patients with secondary hyperparathyroidism.     

Nuclear medicine of the thyroid and parathyroid glands]

Nuclear medicine plays an important role in the diagnosis and treatment of thyroid and parathyroid disorders. Basic nuclear medicine in the diagnosis of thyroid and parathyroid disorders and our clinical study on 131I treatment for differentiated thyroid cancer are described. Characteristics of thyroid, parathyroid, tumor scans and typical bone scintigrams in hyperparathyroidism are presented. Combined 99mTc-MIBI/99mTc-HSA-D SPECT imaging clearly demonstrated localization of ectopic parathyroid adenoma. Very interesting uncommon three cases of thyroid cancer are presented. 99mTcO4- thyroid scan in the first patient demonstrated intense tracer uptake in the lymph node metastasis from papillary microcancer. Post-therapy 131I scan following total thyroidectomy visualized multiple pulmonary metastases. The second patient with metastatic follicular cancer developed thyrotoxicosis with high TSH receptor antibodies. Post-therapy 131I total body scan in the third patient with papillary cancer demonstrated large skull metastasis. Cardiac blood pool and large blood vessel visualization was also clearly seen at this time.     

彩色多普勒超声在甲状旁腺腺瘤诊断中的应用价值

目的:探讨彩色多普勒超声(CDUS)诊断甲状旁腺腺瘤(PTA)的应用价值。方法:应用彩色多普勒超声诊断仪检查10例PTA患者,全部病例经手术病理证实。结果:10例患者经彩色多普勒超声发现甲状旁腺实性肿块11个,经手术证实为PTA的有10个,增生性病灶1个,其中CDUS第一诊断拟诊为PTA的有7例,另有3例第一诊断为甲状腺腺瘤。结论:彩色多普勒超声可以比较准确的诊断PTA。