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Proceeding of the meeting on management of thyroid cancer: an update". Biomed. Pharmacother. 54, 54,
Myocardial dysfunction and adrenergic innervation in patients with Type 1 diabetes mellitus
Is thyroid suppression an effective procedure in improving preoperative sestamibi parathyroid scintigraphy?
OPTIMIZATION OF PEROPERATIVE PROCEDURES
Abstract: Minimally invasive radio-guided surgery (MIRS) of parathyroid adenomas has been favoured by three main factors. One is the significant improvements achieved in preoperative localizing imaging, particularly with sestamibi scintigraphy. Another is the availability of intra-operative quick parathyroid hormone measurement, and finally the increase in availability of the intra-operative gamma probes in many surgical centres especially those performing sentinel node biopsy. In contrast with the traditional wide bilateral neck exploration (BNE), MIRS requires strict inclusion criteria: 1) high probability of a solitary parathyroid adenoma, 2) a significant sestamibi uptake in the parathyroid adenoma, 3) absence of a concomitant thyroid nodular disease, 4) no family history of familial hyperparathyroidism (HPT) of multiple endocrine neoplasia, 5) no previous neck irradiation. Following these criteria about 60-70% of all primary HPT patients are suitable for a MIRS. Two main protocols for MIRS have been proposed. The single day, imaging and surgery, protocol is based on the injection of a 740 MBq dose of Tc-99m sestamibi with the purpose of obtaining scintigraphic imaging and then MIRS within 3 hours from radio-tracer injection. An alternative is for imaging to be performed a few days before surgery, with a further small administered activity of 37MBq of Tc-99m sestamibi injected intravenously in the operating theatre a few minutes before commencing the intervention for the purpose of MIRS only. The latter protocol allows both better planning of operating theatre scheduling and reduction of the radiation exposure to the surgical staff. The main advantages of MIRS in respect to the traditional BNE include less surgical trauma, a shorter duration of anaesthesia and surgery, a shorter hospital stay with the possibility of same-day discharge, less post-surgical pain with improved cosmetic results and lower costs. Moreover, MIRS has proven to be a safe technique with a low morbidity rate and a cure rate higher than 95% in patients with primary HPT. ((C) 2003 Lippincott Williams Wilkins)
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
PRIMARY HYPERPARATHYROIDISM IN PATIENTS TREATED FOR NON-MEDULLARY THYROID CARCINOMA
Abstract: The authors report three cases of primary hyperparathyroidism (HPT) in patients with differentiated thyroid carcinoma (DTC) developed a few years after initial surgical and radiometabolic treatment of DTC. The early diagnosis of HPT in these patients was made possible because of laboratory tests performed during follow-up, including the assay of serum calcium and serum phosphorus levels. Scinti-graphy using 99mTc-MIBI enabled the correct preoperative localisation of a single parathyroid adenoma in two of these patients and multiglandular pathology in the third
99M TC-MIBI RADIO-GUIDED MINIMALLY INVASIVE PARATHYROID SURGERY PLANNED ON THE BASIS OF A PREOPERATIVE COMBINED 99M TC-PERTECHNETATE/99M TC-MIBI AND ULTRASOUND IMAGING PROTOCOL
Abstract: The aims of this study were: (a) to define the accuracy of a preoperative parathyroid imaging protocol based on the combination of technetium-99m pertechnetate/technetium-99m methoxyisobutylisonitrile ((TcO4)-Tc-99m/Tc-99m-MIBI) scan and neck ultrasound (US) in selecting patients with primary hyperparathyroidism (pHPT) eligible for a limited neck exploration, and (b) to investigate the potential role of the intraoperative gamma probe (IGP) in radio-guided minimally invasive surgery. (TcO4)-Tc-99m/Tc-99m-MIBI subtraction scan was performed by means of potassium perchlorate administration with the aim of effecting rapid (TcO4)-Tc-99m wash-out from the thyroid. Minimally invasive surgery using an IGP was commenced some minutes following the injection of a low, 70 MBq, Tc-99m-MIBI dose. Intraoperative PTH (i-PTH) was measured. On the basis of preoperative imaging, 21 pHPT consecutive patients were selected fur a limited neck dissection. In 18 of them, a single parathyroid adenoma was found at surgery and IGP allowed performance of parathyroidectomy through a small, 2-2.5 cm, skin incision with a relatively short surgical duration (mean 38 min). i-PTH rapidly normalised in all cases. In two patients, a parathyroid carcinoma was diagnosed at surgery; consequently, a wide neck exploration associated with a near-total thyroidectomy was performed. No loco-regional metastatic lesions were found and I-PTH rapidly normalised after carcinoma excision. In one patient, i-PTH remained elevated after removal of the enlarged parathyroid gland which was localised by (TcO4)-Tc-99m/Tc-99m-MIBI Scan and US. A bilateral exploration was needed to remove a contralateral enlarged parathyroid gland. Combined, (TcO4)-Tc-99m/Tc-99m-MIBI scan and US imaging correctly localised a single parathyroid gland in 20/21 patients (95.2%); thus, this protocol appears to be accurate enough for the preoperative selection of pHPT patients eligible fur limited neck surgery. Moreover, in these selected patients the IGP seems to be helpful in performing radio-guided minimally invasive surgery
99mTc-MIBI radio-guided minimally invasive parathyroidectomy: experience with patients with normal thyroids and nodular goiters
The surgical approach to primary hyperparathyroidism (HPT) is changing. In patients with a high probability to be affected by a solitary parathyroid adenoma (PA), a unilateral neck exploration (UNE) or a minimally invasive radio-guided surgery (MIRS) using the intraoperative gamma probe (IGP) technique have recently been proposed. We investigated the role of IGP in a group of 84 patients with primary HPT who were homogeneously evaluated before surgery by a single-day imaging protocol including 99mTcO4/MIBI subtraction scan and neck ultrasound (US) and then operated on by the same surgical team. Quick parathyroid hormone (QPTH) was intraoperatively measured in all cases to confirm successful parathyroidectomy. In 70 patients with scan/US evidence of a single enlarged parathyroid gland (EPG) and with a normal thyroid gland, MIRS was planned. In the other 14 patients, the IGP technique was utilized during a standard bilateral neck exploration (BNE) because of the presence of concomitant nodular goiter (11 cases) or multiglandular disease (MGD) (3 cases). The IGP technique consisted of the following: (1) in the operating room, a low 99mTc-MIBI dose (37 MBq) was injected intravenously during anesthesia induction; (2) subsequently, the patient's neck was scanned with the probe by the surgeon to localize the cutaneous projection of the EPG; (3) in patients who underwent MIRS, the EPG was detected intraoperatively with the probe and removed through a small, 2 to 2.5 cm skin incision; (4) radioactivity was measured on the EPG both in vivo and ex vivo, the thyroid, the background and the parathyroid bed after EPG removal. In patients with concomitant nodular goiter, the radioactivity was also measured on the thyroid nodules. Surgical and pathologic findings were consistent with a single PA in 78 patients, parathyroid carcinoma in 2, and MGD in 4. MIRS was successfully performed in 67 of the 70 patients (97.7%) in whom this approach was planned. It must be pointed out that the IGP technique was particularly useful in detecting the PAs located in ectopic site (5 in the upper mediastinum, 2 at the carotid bifurcation) and deep in the neck (6 in the paratracheal/paraesophageal space). Moreover, MIRS was also successfully performed in the seven patients who had undergone previous parathyroid or thyroid surgery. In the other 3 of 70 patients (4.3%), a conversion to BNE was required because a parathyroid carcinoma (2 cases) and a MGD (1 case) were diagnosed during surgical intervention. It is worth noting that in this latter patient affected by MGD, in contrast with the other patients from our series, QPTH remained elevated after the removal of the preoperatively visualized EPG suggesting the persistence of occult hyperfunctioning parathyroid tissue, and another contralateral EPG was found at BNE. Regarding the group of patients in whom a BNE was planned, the IGP helped the surgeon to localize a supernumerary EPG ectopic in the thymus in a patient with MGD, and to localize a PA ectopic to the right carotid bifurcation in a patient with nodular goiter. However, it has to be pointed out that it was difficult for the surgeon to differentiate intraoperatively with the probe the radioactivity of the EPG from that of thyroid nodule(s) in the other 10 patients with HPT with a concomitant nodular goiter, particularly in 6 patients in whom 99mTc-MIBI uptake was higher in thyroid nodule(s) than in EPG. On the basis of these data we can conclude that: (1) in patients with primary HPT with a high scan/US probability to be affected by a single PA and with a normal thyroid gland, IGP appears to be an useful technique with the aim of performing MIRS; (2) a 99mTc-MIBI dose as low as 37 MBq appears to be adequate to successfully perform MIRS; (3) the measurement of QPTH is strongly recommended in patients with HPT selected for MIRS to confirm complete removal of hyperfunctioning parathyroid tissue; (4) MIRS can be useful also in patients with HPT who previously received parathyroid/thyroid surgery with the aim of limiting surgical trauma at reoperation and minimizing the related risk of complications; (5) with the exception of PA located in ectopic sites, IGP does not seem to be a recommendable technique in patients with HPT concomitant nodular goiter
Nuclear medicine imaging procedures in differentiated thyroid carcinoma patients with negative iodine scan
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