Tc-MIBI Scan Research Articles

Recurrent Parathyroid Adenoma at the Same Site Importance of ROLL

Background: Recurrent hyperparathyroidism is defined by the re-appearance of parathyroid hormone (PTH) and high blood calcium levels more than 6 months after successful initial surgery for primary hyperparathyroidism. Many causes are associated with recurrent hyperparathyroidism and one of the main reasons is the presence of parathyroid adenoma. Radio-guided occult lesion localization (ROLL) has emergent role in per-operative localization of pathological lesions. ROLL has established role in breast cancer, axillary and thyroid surgery. ROLL is a valuable addition in parathyroid exploration especially in small sized parathyroid adenomas. ROLL is safe and efficient techniques helping in more accurate lesion centricity. Case presentation A 35 years old female was referred to our Nuclear Medicine department due to recurrently raised Calcium and PTH levels. She had complaints of generalized aches and pains with no visible neck nodule. Her Ultrasound neck showed no abnormal lesion while 99m Tc MIBIscan showed an area of increased radiotracer uptake in the right side of neck. Focused surgical neck exploration was done and a parathyroid adenoma was removed. Conclusions Parathyroid adenoma is a most common cause of primary hyperparathyroidism and usually presents symptomatically with high calcium and parathyroid hormone levels. Parathyroid adenoma is diagnosed by imaging and laboratory studies. One stop management is the surgical removal of 3 and a half removal of parathyroid gland and only sparing half of the gland.

Sensitivity of localization studies performed by various radiologists in the evaluation of parathyroid lesions

Objectives. Preoperative imaging studies are commonly used in the diagnosis of primary hyperparathyroidism to increase the success rate of surgery. In the present study, we aimed to correlate surgical outcomes with the sensitivity of localization studies that were performed by various radiologists. Methods. One hundred eighty-nine patients with preoperative diagnosis primary hyperparathyroidism were included. A total of 174 patients in whom hypercalcemia had been cured by parathyroidectomy, were evaluated retrospectively. In total, 184 lesions were excised from these 174 patients. Ultrasonography (USG) and technetium-99m-methoxy isobutyl isonitrile ( 99m Tc-MIBI) imaging yielded correctly localized lesion in 74 and 108 patients, respectively. Results. The specificity of USG and 99m Tc-MIBI imaging were similar (95.9% and 95.0%, respectively). However, the sensitivity was not satisfactory (45.9% for USG, 62.4% for 99m Tc-MIBI). The gland size was not significant for the rate of lesion detection by 99m Tc-MIBI scan or USG. Significant differences were not observed between the preoperative serum parathormone, serum calcium or 24-hour urine calcium excretion levels and the success rate of localization with either USG or 99m Tc-MIBI. Conclusions. Radiologist experience in ultrasonographic parathyroid imaging was found to affect sensitivity. Therefore, surgeons, radiologists and endocrinologists that perform ultrasonographic evaluation should have extensive experience.

SPECT/CT WITH 99MTC-MIBL IN MONITORING OF ESTHESIONEUROBLASTOMA

This article describes a new approach to the diagnosis of esthesioneuroblastoma. The classical algorithm examination included the whole body 99m Tc-MIBI scans and SPECT/CT of the head. There is no data on this method of diagnosis of esthesioneuroblastoma in the scientific literature. A qualitative visualization of the primary tumor and its recurrence after multimodality treatment was reached. SPECT/CT with 99m Tc-MIBI is a promising method for detecting esthesioneuroblastoma, however further studies are required.

(99m)Tc-MIBI Uptake in a Thyroid Adenoma with Diffuse Adipose Metaplasia.

A 71-year-old female underwent a (99m)Tc-MIBI scan to characterize a cold nodule (30mm) of the left thyroid lobe. The nodule showed diffuse uptake and retention of the radiotracer. After resection, histological examination demonstrated a microfollicular adenoma with diffuse white adipose metaplasia. Although mitochondria in brown adipose tissue have been widely studied, we have only a limited understanding of the relevance of mitochondria in white adipose tissue. Active mitochondria are present in white adipocytes, and this may account for the MIBI uptake, mimicking a hyperproliferation pattern, in our patient.

Role of core needle biopsy for patients with indeterminate, fine-needle aspiration cytology

In this journal of Endocrine, Nasrollah et al. [1] reported a new core needle biopsy (CNB) technique for thyroid nodules classified as indeterminate in fine-needle aspiration (FNA) cytology. This new technique obtains core samples consisting of nodular tissue, extranodular parenchyma, and the nodule’s capsule when it is present. They concluded that this technique is helpful to discern the nature of thyroid nodules classified as indeterminate on FNA. In 1930s, large-needle biopsy using 14-gauge needle without ultrasound (US) had been used for diagnosis of thyroid nodules [2], but it showed no benefit in terms of its safety and efficacy as compared with those of FNA [3]. Therefore, in 1980s, FNA has been used as the standard technique for diagnosing thyroid cancer [4]. CNB has recently been reconsidered for use in the diagnosis of thyroid cancer because modern type, spring-activated CNB under US guidance improved both the safety and efficacy of this technique [5]. The patient comfort during and after CNB or tolerability of this procedure is well reported [6]. The majority of the recent guidelines have recommended CNB for patients with thyroid nodules with previously non-diagnostic FNA results [7–9] and in patients with suspicious lymphoma or anaplastic cancer [8, 9]. However, the American Thyroid Association guidelines recommend repeat FNA for patients with previously nondiagnostic FNA results instead of CNB [10]. Recently, Yeon et al. [11] retrospectively studied a large group of patients with non-diagnostic FNA results and concluded that CNB could reduce both the non-diagnostic and inconclusive results. Their results also showed that CNB could prevent unnecessary diagnostic surgery in 96 % of the patients with repeated, non-diagnostic FNA results. For indeterminate FNA results, F18-FDG-PET/CT or (99 m)Tc-MIBI scan may be helpful in patients with thyroid nodules in which malignancy is suspected on the basis of conventional diagnostic techniques [3, 4]. There are no guidelines recommending CNB. Therefore, repeated, indeterminate results of FNA cause patients to undergo diagnostic surgery [8]. As thyroid FNA has become widely used, unnecessary surgery has increased. In a recent study by Park et al. [12], they retrospectively reported the role of CNB for indeterminate thyroid nodules. Their results showed that CNB is superior to repeat FNA for previously non-diagnostic or indeterminate nodules. In another report on this topic by Na et al. [13], they again prospectively evaluated and suggested that CNB can effectively reduce inconclusive results compared with repeat FNA in nodules with previously non-diagnostic or atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS) FNA results. This may be related to the larger tissue sample and the additional histological information obtained by CNB as compared with FNA. Choi et al. [14] verified the value of CNB in a large study population (N = 191) of patients with AUS and FLUS seen in previous FNA results. In a recent study by Nasrollah et al. [1], 20 patients were diagnosed as follicular neoplasm without false negative results by new CNB technique including nodular tissue, extranodular parenchyma, and the nodule’s capsule. On histology, all but one patient was diagnosed as having follicular adenoma, while the other patient was diagnosed with follicular carcinoma. Adenomatous nodules lack or have a thin fibrous capsule, while follicular neoplasms usually manifest as thick, encapsulated lesions [15]. In W. J. Choi J. H. Baek (&) Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil, Songpa-Gu, Seoul 138-736, Korea e-mail: radbaek@naver.com

Diagnostic performance of 99mTc-MIBI scan in predicting the malignancy of thyroid nodules: a meta-analysis

Several studies have investigated the diagnostic performance of (99m)Tc-MIBI scan in the evaluation of thyroid nodules suspicious for malignancy with conflicting results. The aim of our study is to meta-analyze published data on this topic. A comprehensive literature search of studies published through December 2012 regarding the diagnostic performance of (99m)Tc-MIBI scan in the evaluation of thyroid nodules suspicious for malignancy was carried out. Pooled sensitivity and specificity of (99m)Tc-MIBI scan on a per lesion-based analysis and the area under the ROC curve were calculated. Pathological reports of thyroid nodules were considered as reference standard. Twenty-one studies were included in the meta-analysis. Pooled sensitivity and specificity of (99m)Tc-MIBI scan in detecting malignant thyroid nodules were 85.1 % [95 % confidence interval (95 % CI): 81.1-88.5 %] and 45.7 % (95 % CI: 42.7-48.7 %), respectively, on a per lesion-based analysis, irrespective of eventual results of previous technetium pertechnetate ((99m)TcO4) or iodine-123 ((123)I) scan. The area under the ROC curve was 0.78. A sub-analysis restricted to data on hypofunctioning nodules on (99m)TcO4 or (123)I scans was performed: pooled sensitivity and specificity of (99m)Tc-MIBI scan in these nodules were 82.1 % (95 % CI: 77.2-86.3 %) and 62.8 % (95 % CI: 58.9-66.7 %), respectively, on a per lesion-based analysis. The area under the ROC curve was 0.81. (99m)Tc-MIBI scan is a sensitive diagnostic tool in predicting the malignancy of thyroid nodules. Therefore, this imaging method could be helpful in patients with thyroid nodules in which malignancy is suspected on the basis of conventional diagnostic techniques. Higher specificity can be reached when hypofunctioning thyroid nodules are considered.

Is (99m)Tc-MIBI scintigraphy a predictor of response to pre-operative neoadjuvant chemotherapy in Osteosarcoma?

Multidrug resistance (MDR), which may be due to the over expression of P-glycoprotein (Pgp) and/or MRP, is a major problem in neoadjuvant chemotherapy of osteosarcoma. The aim of this study was to investigate the role of Tc-99m MIBI scan for predicting the response to pre-operative chemotherapy. Twenty-five patients (12 males and 13 females, aged between 8 and 52y) with osteosarcoma were studied. Before the chemotherapy, planar (99m)Tc-MIBI anterior and posterior images were obtained 10-min [tumor-to-background ratio: (T1/B1)10min] and 3-hr after tracer injection. After completion of chemotherapy, again (99m)Tc-MIBI scan was performed at 10-min after tracer injection. In addition to calculation of decay corrected tumor to background (T/B) ratios, using the 10-min and 3-hr images of the pre-chemotherapy scintigraphy, percent wash-out rate (WR%) of (99m)Tc-MIBI was calculated. Using the 10-min images of the pre- and post-chemotherapy scans, the percent reduction in uptake at the tumor site after treatment (Red%) was also calculated. Then after surgical resection, tumor response was assessed by percentage of necrosis. All patients showed significant (99m)Tc-MIBI uptake in early images. Only 9 patients showed good response to chemotherapy (necrosis≥90%) while 16 patients were considered as non-responder (necrosis<90%). There was no statistical significant difference between non-responders and responders in (T1/B1)10min.There was a significant negative correlation between WR% and percentage of necrosis (P=0.001). On the other hand, there was a significant correlation between Red% and percentage of necrosis (P<0.001).There was also statistical significant difference in WR% and Red% between non-responders and responders (both P< 0.001). Washout rate of (99m)Tc-MIBI in pre-chemotherapy scintigraphy as well as Red% using pre- and post-chemotherapy MIBI scintigraphy are useful methods for predicting response to neoadjuvant chemotherapy.

In vivo mouse ^{99m}Tc SPECT scans with bioluminescence imaging validation

The aim of this in vivo study was to evaluate the feasibility of <formula>^{99m}</formula>Tc-labeled cartilage link protein (CLP) probe for the single-photon emission computed tomography (SPECT) of lung cancer. Xenograft mouse model were established from a luciferase expressing cell line derived from a human lung cancer. Bioluminescence imaging (BLI) was carried out prior to <formula>^{99m}</formula>Tc-CLP and <formula>^{99m}</formula>Tc-methoxyisobutyl isonitrile (MIBI) SPECT scans. The image quality of <formula>^{99m}</formula>Tc-CLP scan was validated with BLI and compared with well established <formula>^{99m}</formula>Tc-MIBI scan. Results of multimodal imaging analyses suggested that <formula>^{99m}</formula>Tc-CLP was a sensitive and reliable SPECT agent for lung cancer imaging.

99mTc-MIBI Whole Body Scan: A Potentially Useful Technique for Evaluating Metabolic Bone Disease

Metabolic bone disease due to hyperparathyroidism is characterized by increased bone resorption and new bone formation. 99mTc- hexakis-2-methoxyisobutylisonitrile (99mTc MIBI) accumulation is controlled by metabolic function and cell viability. To investigate, for the first time, the potential of whole body 99mTc MIBI scan for detecting, visually and with the aid of quantitative analysis, bony changes associated with hyperparathyroidism. Eighty-six patients with hyperparathyroidism, referred routinely for parathyroid localization, were included in this case-control prospective study. Each patient was injected with 20-25 mCi of 99mTc MIBI. Routine anterior cervico-thoracic images were obtained for parathyroid localization. Two extra whole body images were acquired and assessed visually and by drawing regions of interest over the mandible, sternum, femur, humeri, spine, and the soft tissue adjacent to the bone. The ratios of bone to soft tissue were calculated and compared to ratios drawn in a control group routinely referred for cardiac imaging and injected with 99mTc MIBI, after confirming the absence of any bone disease. The visual interpretation of the scans showed 48 patients to have increased bone uptake. Quantitative assessment showed significant difference between the mean ratios of the case and control groups. The Kruskal-Wallis test showed significant agreement between visual and quantitative ratios drawn from delayed right and left femora and left humerus images (P < 0.05). 99mTc MIBI whole body imaging is a potentially useful technique for assessing metabolic bone disease associated with hyperparathyroidism. Quantitative analysis helped in confirming the visual findings.

Valor de la PET-FDG negativa en el seguimiento a medio plazo del carcinoma diferenciado de tiroides en pacientes con rastreo con 131I-Na negativo y cifras de tiroglobulina elevadas

This study has aimed to analyze the evolution of patients diagnosed with differentiated thyroid carcinoma (DTC) with a negative (131)I-Na whole body scan (WBS), high levels of serum thyroglobulin (Tg) and negative (18F)fluorodeoxyglucose positron emission tomography (PET-FDG) study.Twenty-three patients diagnosed and treated for DTC were studied retrospectively. Patients were aged between 23 and 83 and had shown, between January 2001 and December 2002, negative WBS, Tg values in a range of suspected recurrence or metastasis (Tg>2 ng / mL with thyroid hormone withdrawal) and a negative PET-FDG study. The patients were monitored clinically, radiologically and analytically for a minimum period of 4 years. After this, a new evaluation was made of their state of disease with a control WBS, also observing the evolution of Tg. All WBS were performed with a 185 MBq diagnostic dose of (131)I-Na.In 18/23 patients, Tg decreased and in 5 it increased. Four patients (17%) were free of active disease (negative WBS Tg<2 ng / mL). A total of 16 patients (70%) were free of disease according to the WBS but had elevated Tg. Three patients (13%) had disease and high levels of Tg, two of them with positive WBS and the third with (99m)Tc-MIBI scan and CT positive.Most patients with a negative WBS, high Tg serum levels and negative FDG PET had good evolution, with descending Tg levels, normal levels even being reached in a significant percentage of them.

Abundant Blood Supply and Low P-Glycoprotein Expression on Dynamic 99mTc-MIBI Imaging Predicted Better Chemotherapy Sensitivity for a Breast Cancer Patient: A Case Report

A patient with a history of breast cancer underwent 3-phase (99m)Tc-methylene diphosphonate (MDP) imaging followed 3 d later by 3-phase (99m)Tc-sestamibi (MIBI) imaging. During the vascular and blood-pool phases, a lymph node over the right clavicle was seen on both the (99m)Tc-MIBI and the (99m)Tc-MDP scans at as early as 30 s and then became hotter. Four months after receiving chemotherapy, the patient achieved a complete response. The lymph node over the right clavicle vanished on ultrasound examination. The similar distribution of the blood-pool phase between the (99m)Tc-MDP and (99m)Tc-MIBI scans indicated that (99m)Tc-MIBI may similarly provide information on vascularization of the lymph node. In addition to indicating vascularization, our (99m)Tc-MIBI protocol may simultaneously provide information on P-glycoprotein expression important for predicting chemotherapy sensitivity. With information on the resistance of a tumor to drugs and the environment in which it dwells, chemotherapy sensitivity might be predicted more precisely.

Influence of thyroid-stimulating hormone on 18F-fluorodeoxyglucose and 99mTc-methoxyisobutylisonitrile uptake in human poorly differentiated thyroid cancer cells in vitro

In poorly differentiated thyroid cancer originating from thyroid follicular cells, the ability to concentrate iodine is lost. This makes recurrence undetectable by (131)I whole-body scan. In this situation, other radiopharmaceuticals, such as (18)F-fluorodeoxyglucose ((18)F-FDG) and technetium-99m-methoxyisobutylisonitrile ((99m)Tc-MIBI), are used to evaluate recurrence or metastasis. Some reports suggest that (18)F-FDG uptake is increased by thyroid-stimulating hormone (TSH) stimulation. This study aimed to determine the influence of TSH on (18)F-FDG and (99m)Tc-MIBI uptake in human poorly differentiated thyroid cancer cells in vitro. The cells were stimulated with 1000 muU/ml of recombinant human thyroid-stimulating hormone (rhTSH) for 1 day, 3 days, and 5 days. Each cell was incubated with 0.5 MBq/ml-1 MBq/ml of (18)F-FDG or 0.5 MBq/ml-1 MBq/ml of (99m)Tc-MIBI for 1 h at 37 degrees C. The uptake of each radiopharmaceutical in the cells was quantified as a percent of whole radioactivity per total viable cell number. The quantification of glucose transporter 1, 2, 3 and 4 mRNA expression was measured using RT-PCR. TSH stimulation increased (18)F-FDG uptake in a time-dependent manner. Following 5 days of rhTSH stimulation, (18)F-FDG uptake was approximately 2.2 times that of the control. The increase in (18)F-FDG uptake following rhTSH stimulation was correlated to the increase in GLUT4 mRNA level. The GLUT1 mRNA level was unchanged. An increased uptake of (99m)Tc-MIBI was observed with a pattern similar to that of (18)F-FDG. The (99m)Tc-MIBI uptake was approximately 1.5 times that of the control 5 days later. These results suggest that TSH stimulates (18)F-FDG and (99m)Tc-MIBI uptake in poorly differentiated papillary thyroid cancer, and therefore (18)F-FDG-PET or (99m)Tc-MIBI scans under TSH stimulation may be more accurate than under suppression.

Technetium-99m 2-methoxy-isobutyl-isonitrile uptake scintigraphy in detection of the bone marrow infiltration in multiple myeloma: correlation with MRI and other prognostic factors

Whole-body scintigraphy with Technetium-99m 2-methoxy-isobutyl-isonitrile ((99m)Tc-MIBI) has been proposed as a useful method for demonstrating the areas of active bone marrow infiltration in multiple myeloma (MM). In this study, we compared the (99m)Tc-MIBI scan with magnetic resonance imaging (MRI), skeletal X-ray survey, and biochemical markers of disease activity in MM to determine its potential in predicting the extension of the disease. Twenty-four myeloma patients had undergone to the (99m)Tc-MIBI scan. Only two patients showed negative results in the (99m)Tc-MIBI scan; one had clinically active disease, and the other was on remission. MRI was performed to 18 clinically active patients, and 16 of them showed positive myelomatous bone marrow involvement. No significant difference was found between the (99m)Tc-MIBI scan and MRI in predicting the extension of bone marrow infiltration in MM (p = 0.11). (99m)Tc-MIBI scores were correlated with bone marrow neoplastic plasma cell ratio (p = 0.005), serum paraprotein level (p < 0.001), serum lactate dehydrogenase (p = 0.031), and beta-2 microglobulin (p = 0.045). The (99m)Tc-MIBI scan showed disease activity better than the skeletal X-ray survey (x2 = 5.299, p = 0.021). A significant decrease was found in posttreatment (99m)Tc-MIBI scores of the patients with positive overall response (p = 0.016). The (99m)Tc-MIBI scan is a noninvasive test that can show the extension of the disease in MM. It seems that the (99m)Tc-MIBI scan and MRI show extension and intensity of the myelomatous bone marrow infiltration equally well. The (99m)Tc-MIBI scan can be an alternative to MRI when it is not available or if there is any limitations for its usage.

Endoscopic bilateral neck exploration versus quick intraoperative parathormone assay (qPTHa) during endoscopic parathyroidectomy: A prospective randomized trial

Quick intraoperative parathormone assay (qPTHa) during paratyroidectomy has become a standard procedure for patients with primary hyperparathyroidism (PHPT). This paper aims to compare endoscopic bilateral neck exploration (BE) versus focused parathyroidectomy plus qPTHa during minimally invasive video-assisted parathyroidectomy (QM). The endpoints of the study are the mean operative time and outcome of the surgical procedure (PTH and calcemia normalization at one and six months postoperatively). Forty patients with PHPT, positive to preoperative localization studies (ultrasonography evaluation and (99)Tc-MIBI scan) for a single parathyroid adenoma, were randomly allotted into two groups. In the first group (QM), 20 patients (17 women, three men, mean age 57.6 years) underwent focused endoscopic parathyroidectomy (MIVAP tecnicque) plus qPTHa . In the second group (BE) 20 patients (17 women, three men, mean age 59.6 years) underwent endoscopic parathyroidectomy plus bilateral exploration in order to check the integrity of the remaining glands. There were no significant differences between groups at baseline. No conversion to cervicotomy was required. No postoperative complications were reported. The mean operative time was 32.0 vs 33.1 min [BE and QM group respectively, p = not significant (ns)]. A second macroscopically enlarged gland was removed in four patients in the BE group. Only one out of four glands was reported to be hyperplastic in the final histology. All patients were discharged on the first postoperative day. Calcemia levels were normalized in all patient of both groups, despite persistently high level of serum PTH in one patient in the QM group. BE can be performed endoscopically, avoiding both the time necessary for qPTHa and its cost, with the same effectiveness, but might in few cases lead to the unjustified removal of parathyroid glands slightly enlarged but not necessarily pathologic.

99mTc-MIBI imaging of cutaneous AIDS-associated Kaposi's sarcoma

Kapoksi's sarcoma (KS) is a common neoplasm complicating acquired immunodeficiency syndrome (AIDS). Skin, mucus membranes, lymph nodes, gastrointestinal tract and lungs may be involved. Kaposi's sarcoma has been demonstrated by scintigraphy, and a (99m)Tc-hexakis-2-methoxy isobutyl isonitrile (MIBI) scan can demonstrate lymphoma and tumors of the brain, nasopharynx, thyroid, parathyroid, lung, breast and kidney. It may also be useful for detecting and delineating the extent of KS. The objective of this study was to determine the efficacy of (99m)Tc-MIBI scanning to demonstrate cutaneous AIDS-associated KS, lymphedema and lymphadenopathy in the extremities. Whole body (99m)Tc-MIBI scans were obtained on 40 patients with AIDS-associated KS. Abnormal uptake of (99m)Tc-MIBI in the skin, subcutaneous soft tissues and lymph nodes was compared with the clinical assessment. The (99m)Tc-MIBI uptake was noted in the cutaneous/subcutaneous KS of the extremities with a sensitivity of 73.53%, a specificity of 96.91% and an accuracy of 91.31%. Abnormal lymph nodes and lymphedema were detected in more patients on (99m)Tc-MIBI scans (33 and 18 patients) than clinical assessment (10 and 12 patients), respectively. Lymphedema of the lower extremity was found in four of 17 patients without any palpable or abnormal lymph node uptake of (99m)Tc-MIBI in the inguinal regions. Follow-up (99m)Tc-MIBI scans after treatment showed no uptake in the skin lesions and decreased uptake in the lymph nodes corresponding to complete clearing on clinical assessment. (99m)Tc-MIBI imaging provides additional information on the extent of lymph node involvement and more precise staging and therapeutic planning. It may be useful as a predictive test or follow up of response of cutaneous KS to treatment.

Nueva técnica quirúrgica para glándulas paratiroides intratorácicas: la videotoracoscopia con detección de Tc-MIBI intraoperatoria

Ectopic mediastinal parathyroid glands are uncommon (1-11% of all cases of hyperparathyroidism). Median sternotomy used to be performed to resect them, with large and painful incisions that prolonged the length of hospital stay. Current imaging techniques (thoracic computed tomography and Tc-mibi scan) can accurately locate the ectopic glands, allowing minimally invasive exploration. We report a new surgical technique: video-assisted thoracoscopic resection associated with intraoperative Tc-mibi scintigraphy for ectopic mediastinal parathyroid glands. This technique allows minimally invasive access and reduces complications and length of hospital stay. Therefore we believe that video-assisted thoracoscopy could become the technique of choice in patients with high surgical risk and a fifth ectopic parathyroid gland. We report the case of a 49-year-old man in whom surgery was successful.

Unilateral Surgery for Hyperparathyroidism: Indications, Limits, and Late Results—New Philosophy or Expensive Selection without Improvement of Surgical Results?

We assessed the "late" results after unilateral parathyroidectomy (PTX) performed for selected indications. From October 1998 throughout March 2001 we operated on 454 patients for hyperparathyroidism (HPT). A positive unifocal (99m)tc-MIBI scan was required for the unilateral approach to be used. Intact parathormone (PTH) measurements were done intraoperatively. Postoperative calcium and PTH serum levels of unilaterally operated patients were checked. Follow-up has been 16.2 months (range 6-40 months). Of the 454 patients, 336 (74.0%) were not eligible for the unilateral approach; and 125 (27.5%) of the 454 patients had renal HPT. Among the 329 patients with primary HPT, 125 (38.0%) were excluded for well established reasons, and in 77 other cases (23.5%) preoperative imaging results did not allow the unilateral approach. Altogether, 126 patients (38.3%) with primary HPT were selected for the unilateral approach. Of the 126 unilateral operations, 8 (6.3%) had to be converted to a bilateral procedure. Among the 118 patients with a unilateral approach, 3 patients have been reoperated for overlooked contralateral disease, and 13 dropped out of the study. A total of 102 postoperative calcium and PTH serum late levels are known: 90 (88.2%) patients had normal levels; 10 (9.8%) had a high PTH level, and 2 (1.9%) had high ionized calcium levels. The failure rate in selected cases was 4.2% (5/118) (three were reoperated, and two had a supranormal postoperative ionized Ca level). Even with stringent indications, the late results of unilateral surgery (95.8% cure rate) barely matched those of conventional bilateral surgery (97.6% cure rate). The economic impact of such a surgical strategy should be clarified.

99mTc-MIBI in the evaluation of breast cancer biology.

A major area of interest in nuclear medicine is the scintigraphic in vivo evaluation of complex cellular processes involved in tumour growth, progression and response to treatment with the aim of defining the biological properties that may orient clinicians towards different adjustments of therapy in individual patients. In the last decade, (99m)Tc-labelled lipophilic cations emerged as suitable tools to trace specific cellular processes and functions in a variety of malignant tumours, including breast cancer. Among these agents, (99m)Tc-methoxyisobutylisonitrile (MIBI) is the most widely evaluated tracer and may serve as a paradigm for this class of compounds. Many clinical studies have been performed to correlate (99m)Tc-MIBI uptake or clearance with histological, molecular and biochemical markers of various cellular processes, including apoptosis, proliferation, P-glycoprotein expression and neoangiogenesis. The final picture emerging from these studies is that the early tracer uptake reflects the mitochondrial status, which is affected by both apoptosis and proliferation, whereas the tracer clearance reflects the activity of drug transporters such as P-glycoprotein. On the basis of the imaging parameter chosen for the analysis of (99m)Tc-MIBI scan in breast cancer patients, the biological information provided may be related to different cellular processes that ultimately govern tumour response to treatment.

(99m)Tc-MIBI radio-guided surgery for recurrent thyroid carcinoma: technical feasibility and procedure, and preliminary clinical results.

The preliminary results of technetium-99m methoxyisobutylisonitrile (MIBI) radio-guided surgery (RGS) in patients with differentiated thyroid carcinoma (DTC) and iodine-131-negative (non-functioning) recurrent disease are reported. Eight consecutive DTC patients were selected for RGS on the basis of pre-operative imaging findings: a (99m)Tc-MIBI scan consistent with local recurrence was taken as the principal inclusion criterion. The RGS procedure that we developed consisted in the injection of a low dose of (99m)Tc-MIBI (37 MBq) in the operating theatre a few minutes before the beginning of the intervention, with use of a hand-held gamma probe for the intra-operative detection of (99m)Tc-MIBI-avid tumoural foci. Radioactivity was measured in tumoural foci both in vivo and ex vivo, in the background and in the tumoural bed after lesion extirpation. After follow-up for 2-10 months, stable normalisation of serum thyroglobulin (Tg) levels was observed in six out of the seven patients in whom, during the intervention, the gamma probe-detected radioactivity in the neck fell to background values after tumour extirpation. In another patient the persistence of high radioactivity levels in the tumoural bed after lesion removal correctly suggested disease persistence (deep tracheal infiltration). These preliminary data suggest the feasibility of RGS in DTC patients with locoregional non-functioning but (99m)Tc-MIBI-avid recurrence by injection of a low, 37 MBq dose of (99m)Tc-MIBI just before the beginning of the intervention.

Measurement of Myocardial Perfusion with Electron Beam Tomography: Comparison with 99m Tc-MIBI Scan

Purpose: To compare the accuracy with which electron beam tomography (EBT) and -MIBI scanning measure myocardial perfusion valve. Materials and Methods: Twenty-two subjects [normal volunteers (n = 6), patients in whom ischemic heart disease was diagnosed (n = 5), and those in whom ischemic heart disease was suspected but who were found to be normal (n = 11)] were involved in this study. EBT was performed after bolus injection of contrast media (50 ml of Iopamiro 370 or Optiray 350, 3 ml/sec). The myocardium was divided into 16 segments according to the classification devised by the American Society of Echocardiography, and each myocardial perfusion value was calculated by post-image processing. A pharmacologic stress test was performed in all subjects except four patients with acute myocardial infarction, and myocardial perfusion reserve ratios were assessed. Single photon emission computed tomography (SPECT) was performed after the injection of 20 mCi of -MIBI. Any segments with moderate to severe photon defect on visual analysis of SPECT were identified and perfusion values determined by EBT in normal and ischemic segments were compared. Results: No difference in myocardial perfusion was found between volunteers and the suspected group. Their perfusion values were 0.710.14 ml/g/min in the resting state and 1.160.24 ml/g/min on the stress test and the myocardial perfusion reserve ratio was, therefore, 1:1.680.38. In ischemic patients, -MIBI scanning revealed a perfusion defect in 28 segments, and on EBT the measurement obtained was 0.540.19 ml/g/min. The remaining 324 perfusion segments shown by SPECT to be normal showed a perfusion value of 0.790.22 ml/g/min on EBT. Conclusion: Compared with -MIBI scanning, the measurement of myocardial perfusion by EBT provides absolute quantification of perfusion value and more detailed anatomic information.