99m Tc-methoxyisobutylisonitrile Research Articles

Minimally Invasive Parathyroidectomy: Are Auxiliary Methods Necessary?

To determine the success rate of minimally invasive parathyroidectomies (MIPs) with preoperative scintigraphy and ultrasonography, and to assess whether these imaging modalities are sufficient. Observational study. Department of General Surgery, University of Health Sciences, Kanuni Sultan Süleyman Training and Research Hospital, Istanbul, Turkey between March 2017 and December 2019. Medical records of 61 patients, who underwent MIP to treat primary hyperparathyroidism, were examined. Age, gender, and pre- and postoperative calcium, parathormone, and phosphorus levels were obtained from patient records. For all patients, the parathyroid (PT) glands were localised, using ultrasonography and Tc-99m methoxyisobutylisonitrile (MIBI) scintigraphy. The average patient age was 56.89 ± 13.47 years. Of the patients, 83.6% (n = 51) were females. Localisation of the PT glands with preoperative scintigraphy had an accuracy rate of 100%. However, ultrasonographic localisation was unsuccessful in five patients. Adenomas were noted in 44 patients (72.1%), hyperplasia in 15 patients (24.6%), and neoplasia in two patients (3.3%). Serum parathormone and calcium levels were measured 24 hours after surgery, and were found to be significantly reduced compared to the corresponding preoperative levels (p <0.001). Hypocalcaemia developed in four patients (6.6%), two (3.3%) of which were symptomatic. After three months, persistent hyperparathyroidism developed in five patients (8.2%). Parathyroid scintigraphy has been demonstrated to be the gold standard for the preoperative localisation of PT glands. In the absence of scintigraphy, ultrasound guidance is the next useful technique for PT gland localisation. Key Words:Minimal invasive parathyroidectomy, Parathyroid scintigraphy, Ultrasonography, Parathormone.

Optimization of Ordered Subset Expectation Maximization Parameters for Image Reconstruction in Tc-99m Methoxyisobutylisonitrile Myocardial Perfusion SPECT and Comparison with Corresponding Filtered Back Projection-Reconstructed Images.

Purpose of the Study:To establish the most appropriate ordered subset expectation maximization (OSEM) parameters for image reconstruction in Tc-99m methoxyisobutylisonitrile (MIBI) myocardial perfusion SPECT (MPS) and comparison with corresponding filtered back projection (FBP)-reconstructed images.Methods:A total of 99 stress–rest MPS studies (47 normal and 52 abnormal) were retrospectively analyzed using 16 different combinations of iterations and subsets. Images were reconstructed both with and without postreconstruction Butterworth filter (cutoff frequency and order for stress: 0.4 and 10 and for rest: 0.52 and 5, respectively) for each combination. A total of 3168 images were evaluated qualitatively by two nuclear medicine physicians on a scoring scale of 1–4. Best visual quality image iteration–subset combination was determined for each patient both with and without Butterworth filter and was further compared with FBP-reconstructed image. The interobserver agreement was obtained using kappa statistics.Results:The best quality images were obtained using a combination of four iterations and six subsets for both with and without Butterworth filter. The value of kappa for interobserver agreement for OSEM images with Butterworth filter was 0.570 and for OSEM images without Butterworth filter was 0.857. On comparison, FBP images were better than OSEM-reconstructed images without Butterworth filter (P < 0.0001 calculated using Fisher's exact test) with substantial agreement (kappa = 0.628). However, OSEM-reconstructed images with Butterworth filter were better than FBP images and showed moderate agreement (kappa = 0.486).Conclusion:The most appropriate OSEM reconstruction parameter in Tc-99m MIBI MPS is 4-iteration and 6-subset combination. FBP-reconstructed images were better than the images reconstructed with OSEM without postreconstruction Butterworth filter. However, OSEM-reconstructed image with Butterworth filter was better than FBP images.

Diagnosing cystic duct patency during myocardial perfusion imaging (MPI), using Tc99m Sestamibi (MIBI), as an adjunct benefit in the acute setting.

Objective:Tc99m methoxy isobutyl isonitrile (MIBI) has been used for myocardial perfusion imaging (MPI) for the detection of ischemia. This study aimed to investigate the feasibility of effectively evaluating cystic duct patency, during routine visual analysis of the raw MPI and/or with the three-dimensional reconstructed data.Methods:A retrospective investigation of 91 patients undergoing cardiac MIBI scan for acute chest pain and hepatobiliary scintigraphy (HBS) was performed, within no more than 3 months for suspected gallbladder obstructive disease. Gallbladder visualization during either the stress or rest portion of the MIBI was indicative of cystic duct patency. These results were compared to those by the HBS studies.Results:Ten patients had the MIBI and HBS 4 days apart, both analyses concurred 100% with the diagnosis of cystic duct patency. 16 patients had both examinations between 4 days and 3 weeks and had an agreement of 87.5% with cystic duct patency. 65 patients had both tests 3 weeks to 3 months apart and had an agreement of 84.6% with cystic duct patency.Conclusion:The initial results of this study indicate that MPI with Tc99m MIBI is useful in detecting a patent cystic duct, above all in the setting of acute gallbladder pathology.Advances in knowledge:In this article, we introduce a novel method to diagnose cystic duct patency in the acute setting thus effectively ruling out acute cholecystitis, during MPI. Our method can potentially improve patient outcomes by reducing the volume of imaging needed to exclude a diagnosis of acute gallbladder pathology. This in turn, keeps in line with decreasing the cost for the patient, leading to a more sound value-based care.

The role of Tc-99m MIBI scintigraphy in clinical T1 renal mass assessment: Does it have a real benefit?

IntroductionDespite the increasing accuracy of imaging modalities, the rate of benign renal tumors misclassified as malignant before surgery still non-negligible. Tc-99m sestamibi was demonstrated to be a possible reliable agent in discriminating oncocytoma from renal cell carcinoma (RCC). We aimed to study the efficacy of Tc-99m MIBI tumor scintigraphy in evaluating clinical T1 renal masses. Methods and MaterialsBetween July 2017 and March 2019, patients with clinical T1 renal mass underwent preoperative Tc-99m sestamibi tumor scintigraphy. Tc-99m sestamibi tumor scintigraphy findings were correlated with the postoperative pathology results. ResultsA total of 90 renal masses were included in the study. Male to female ratio was 67/23. The mean age and tumor size were 55.5 ± 11.4 years and 4 ± 1.4 cm, respectively. In pathological evaluation, 20% (18/90) of masses were reported as benign (10 oncocytomas, 4 angiomyolipomas (AML), 2 chronic sclerosis, 1 fibroma and 1 hydatid cyst).While Tc-99m sestamibi uptake was positive in all oncocytomas; 6 patients with chronic sclerosis, fibroma, hydatid cyst and angiomyolipoma pathologies had no uptake. Except for 5 chromophobe cell RCC and 3 oncocytic papillary RCC masses, malignant lesions had no uptake.In predicting benign pathology, Tc-99m sestamibi tumor scintigraphy had positive and negative predictive value of 60% and 91.3%, respectively. The mean Tc-99m 2-methoxy isobutyl isonitrile lesion/normal renal parenchyma ratio of benign and malignant lesions was 0.6 and 0.37, respectively. A relative uptake of 0.49 was an acceptable cutoff point to discriminate oncocytomas from all other pathologies. ConclusionTc-99m sestamibi tumor scintigraphy has a beneficial role in the assessment of clinical T1 renal mass. Masses with negative uptake harbor high probability of being malignant. While evaluating masses with positive uptake, it should be kept in mind that some malignant pathologies may demonstrate similar results.

The role of 99mTc-MIBI in the evaluation of non-functional thyroid gland nodules

Aim: The objective of the study is to show the role of 99mTc methoxyisobutylisonitrile (99mTc-MIBI) with planar imaging and single photon emission tomography with “low dose” CT (SPECT-CT) in a work up of non-functioning thyroid nodules on imaging with 99mTc- pertechnetate, which were confirmed by ultrasound examination. Patients and methods: Patients who underwent thyroid imaging with 99mTc-MIBI in the period from 2008 to 2018 were reviewed. The findings were compared with PHD results. The imaging was performed on gamma camera with high resolution collimator as planar scintigraphy and SPECT-CT. The results of fine needle aspiration biopsy were classified by the Bethesda classification, while PHD results were classified, as benign or malignant. Results: In the period from 2008-2018, 271 thyroid imaging with 99mTc- MIBI were performed. In 42 patients all-inclusive criteria were met.Out of those 42 patients, 28 of the PHD findings were concordant with the imaging, i.e. a node was presented as hypermetabolic. The calculated negative predictive value of the procedure is 78.6% (NPV = 11/ (3+11) = 0,786), and positive predictive value 18% (PPV = 5/ (5+23) = 0.179). Conclusion: Given the high negative predictive value, obtained from our results, 99mTc -MIBI imaging may be recommended as a complementary diagnostic method to fine-needle aspiration (FNA) in work up of thyroid nodules.

Diagnostic Performance of Technetium-99m Methoxy-Isobutyl-Isonitrile for Differentiation of Malignant Thyroid Nodules: A Systematic Review and Meta-Analysis.

The purpose of the current study was to investigate the diagnostic performance of technetium-99m (Tc-99m) methoxy-isobutyl-isonitrile (MIBI) for differentiation of malignant thyroid nodules (TN) through a systematic review and meta-analysis. The MEDLINE/PubMed and EMBASE database, from the earliest available date of indexing through January 31, 2018, were searched for studies evaluating the diagnostic performance of Tc-99m MIBI for TN. The sensitivities and specificities were determined across studies, positive and negative likelihood ratios (LR+ and LR-) were calculated, and summary receiver operating characteristic curves were constructed. Across 22 studies (2421 patients), the pooled sensitivity for Tc-99m MIBI thyroid scan was 0.87 [confidence interval (CI) 0.76-0.93] with heterogeneity (I2 = 92.3) and a pooled specificity of 0.78 [CI 0.67-0.86] with heterogeneity (I2 = 96.4). LR syntheses gave an overall LR+ of 4.0 [CI 2.5-6.3] and LR- of 0.17 [CI 0.09-0.32]. The pooled diagnostic odds ratio was 24 [CI 63-176]. The hierarchical summary receiver operating characteristic curve indicates that the area under the curve was 0.90 [CI 0.87-0.92]. In meta-regression analysis, no definite variable was the source of the study heterogeneity. The current meta-analysis shows a moderate sensitivity and specificity of Tc-99m MIBI thyroid scan for differentiation of malignant TN. However, the diagnostic odds ratio was relatively low and the LR scattergram indicated that Tc-99m MIBI thyroid scan is not useful for confirming the presence of malignant TN or for its exclusion. Therefore, Tc-99m MIBI thyroid scans should be used restrictively and interpreted cautiously when assessing TN for malignancy.

Semi-quantitative assessment of pulmonary arterial hypertension associated with congenital heart disease through myocardial perfusion imaging.

The study aimed to use myocardial perfusion imaging (MPI) as a semi-quantitative method to assess the clinical severity of pulmonary arterial hypertension (PAH) in patients with congenital heart disease (CHD). A total of 24 patients with PAH related to CHD (PAH-CHD) who received interventional or medical treatment were included. All patients underwent physical examination, cardiac function evaluation, biochemical test, echocardiography, right heart catheterization (RHC), and MPI with 99mTc-methoxyisobutyl isonitrile (99mTc-MIBI) pre and 6 months post treatments. The correlation between MPI target/background (T/B) ratios and other variables were calculated. The receiver operating characteristic (ROC) curves were developed to evaluate the diagnostic value of T/B ratios. Most of the cardiac functional parameters, surplus pulse O2 (SPO2), biochemical values and right heart catheterization parameters were found significantly elevated after treatment (P<0.05). Pre-treatment MPI showed that T/B ratio had strong correlations with SPO2, Borg scale, cardiac output (CO), cardiac index (CI), right ventricular stroke volume (RV-SV), pulmonary artery pressure (PAP), total pulmonary resistance (TPR), total pulmonary resistance index (TPRI), pulmonary vascular resistance (PVR), and pulmonary vascular resistance index (PVRI). After 6 months treatment, the correlation between T/B ratios and most of these parameters measured were reduced. Receiver operating characteristics curves showed that the diagnostic performance of MPI T/B ratio in moderate/severe PAH patients was significant. The area under the curve (AUC) when measured pre-treatment was 0.929 (P=0.002) and reduced to 0.800 (P=0.046) at post-treatment. Semi-quantitative MPI has high diagnostic value in evaluating the severity level of pulmonary arterial hypertension in patients with congenital heart disease. The diagnostic performance of MPI at pre-treatment patients was superior to that at post-treatment. More cases need to be included for further study.

Influence of single photon emission computed tomography (SPECT) reconstruction algorithm on diagnostic accuracy of parathyroid scintigraphy: Comparison of iterative reconstruction with filtered backprojection.

Background & objectives:Preoperative localization of parathyroid lesions is essential for improving the results in patients with primary hyperparathyroidism. The purpose of this study was to evaluate retrospectively the value of technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) and to compare the diagnostic accuracy of iterative reconstruction (IR) and filtered backprojection (FBP) reconstruction algorithms about localization of parathyroid lesions.Methods:Forty four patients with primary hyperparathyroidism, in whom histopathological correlation could be performed, were included in the study. Dual-phase Tc-99m parathyroid scintigraphy was performed 20 and 120 min after injection of 740 MBq Tc-99m MIBI in all patients. Tomographic images were acquired 120 min after the administration of radiopharmaceutical. The SPECT data were evaluated using an IR as well as a FBP algorithm. In 23 of 44 patients, SPECT acquisitions were performed in 64×64 matrix; in the remaining 21 patients, tomographic data were collected in 128×128 matrix. The imaging results were compared with pathological findings and sensitivities of both reconstruction algorithms, and planar views were calculated.Results:Using planar MIBI scans, abnormal parathyroid glands were correctly localized in 75 per cent of the cases. Sensitivity increased to 77 per cent using SPECT with FBP and to 84 per cent with IR. When the sensitivities were calculated according to the acquisition matrix, these were 95 per cent (20/21) and 85 per cent (18/21) for IR and FBP, respectively in patients in whom 128×128 matrix was used. The sensitivities were lower in patients who were imaged with 64×64 matrix; these were calculated as 74 per cent (17/23) and 70 per cent (16/23) with IR and FBP, respectively.Interpretation & conclusions:Our findings showed that compared to planar scintigraphy, Tc-99m MIBI SPECT was more sensitive diagnostic modality in the detection of abnormal parathyroid tissues. Image quality and sensitivity may be improved further when larger matrices with IR are used instead of FBP algorithm.

Factors affecting the sensitivity of Tc-99m methoxyisobutylisonitrile dual-phase parathyroid single photon emission computed tomography in primary hyperparathyroidism.

The aim of this study was to investigate the effects of thyroid diseases and regularly used medications on the sensitivity of Tc-99m methoxyisobutylisonitrile (MIBI) dual-phase parathyroid single photon emission computed tomography (SPECT) and to define indicatives of the result of the study. Overall, 218 primary hyperparathyroidism patients (190 women, 28 men, mean age: 57±14 years) with thyroid-parathyroid ultrasonography and Tc-99m MIBI dual-phase parathyroid SPECT were retrospectively enrolled. Patients were divided as follows: a positive SPECT group [119 (54.6%) patients] and a negative SPECT group [99 (45.4%) patients]. The effects of thyroid diseases and use of calcium channel blockers, β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, oral antidiabetics, thyroid hormone preparates, nonsteroidal anti-inflammatory drugs, and proton pump inhibitors on the sensitivity of Tc-99m MIBI dual-phase parathyroid SPECT were investigated. The frequency of NSAID usage was higher in the negative scan group (P<0.001). No significant difference was detected in terms of coexisting thyroid disease or usage of other medications. Overall sensitivity, specificity, positive, and negative predictive value of Tc-99m MIBI dual-phase parathyroid SPECT were calculated to be 89.6, 92.5, 94.1, and 86.9%. The sensitivity was low only in nonsteroidal anti-inflammatory drug users (75.6%) compared with nonusers (96.5%). Logistic regression showed that ultrasonography was indicative of a positive scan and the possibility of a negative result was increased by regular usage of nonsteroid anti-inflammatory drugs (odds ratio: 0.262, confidence interval: 0.128-0.538; P<0.001) CONCLUSION: Among various drug groups, NSAIDs may decrease the sensitivity of Tc-99m MIBI SPECT and, provided that these novel data are supported by other studies, patient preparation may be modified to stop NSAIDs before Tc-99m MIBI dual-phase parathyroid SPECT.

An unusual mediastinal parathyroid carcinoma coproducing PTH and PTHrP: A case report.

Parathyroid carcinoma (PTCA) is a rare disease, and ectopic PTCA is particularly rare. Parathyroid hormone-related protein (PTHrP) expression in PTCA has not been previously described in the relevant literature to the best of our knowledge. The present study reports a unique case with a mediastinal parathyroid carcinoma producing parathyroid hormone (PTH) and PTHrP. A 53-year-old man presented with hyperparathyroidism symptoms, including fatigue, chest pain, dizziness, muscular soreness, polyuria, night sweats and renal stones. However, neck ultrasound revealed no significantly abnormal thyroid or parathyroid nodules. Tc99m methoxyisobutylisonitrile (Tc99m-MIBI) scintigraphy scanning indicated an ectopic mediastinal parathyroid adenoma. Histopathological examination revealed PTCA, and the tumor tissue was coproducing PTH and PTHrP. The patient underwent successful surgical operation. Serum calcium and PTH levels remained within normal ranges, and there was no tumor recurrence observed at a 3-year follow-up appointment. Although rare, ectopic parathyroid glands may lead to malignant disease. Clinical symptoms, biochemical tests, ultrasound and Tc99m-MIBI scintigraphy scanning may assist with the diagnosis of this disease. Hypersecretion of PTHrP and PTH contributed collaboratively to the pathogenesis of hypercalcemia due to PTCA. Complete surgical resection with microscopically negative margins is the recommended treatment for PTCA and offers the best chance of a cure.

Clinical Utility of Tc-99m MIBI SPECT/CT for Preoperative Localization of Parathyroid Lesions.

We aimed to demonstrate the role of SPECT/CT in preoperative localization of parathyroid lesions in patients with hyperparathyroidism who had technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI) dual-phase parathyroid scintigraphy. We evaluated retrospectively the scintigraphic data of 103 patients who had parathyroidectomy after Tc-99m MIBI dual-phase parathyroid scintigraphy with SPECT/CT. The planar and SPECT/CT images were evaluated separately to determine their efficacy in localizing parathyroid lesions. These results were then compared with surgical data. There were 84 female and 19 male patients whose mean age was 54 ± 12years. A total of 115 parathyroid lesions in 103 patients were resected during operations. In 87 patients, with both planar and SPECT/CT images, a total of 100 lesions could be detected correctly. In 11 patients, only SPECT/CT images could show 13 subcentimetric lesions. In three patients, three lesions were evaluated as parathyroid lesions both with planar and SPECT/CT images, but according to histopathologic evaluation, they came out to be nonparathyroidal lesions. In two patients, two parathyroid lesions could not be detected preoperatively neither with planar nor with SPECT/CT images. The lesion-based sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 87 %, 99 %, 97.1 %, 95.3 %, and 95.8% for planar images and 98.3 %, 99 %, 97.4 %, 99.4 %, and 98.8% for SPECT/CT images, respectively. Tc-99m MIBI parathyroid scintigraphy should be a diagnostic modality of choice in preoperative evaluation of patients with hyperparathyroidism. SPECT/CT has an incremental value both in demonstrating subcentimetric lesions and in accurately localizing lesions anatomically.

Surgical treatment for mediastinal parathyroid adenoma causing primary hyperparathyroidism.

BackgroundPrimary hyperparathyroidism is a rare disease characterized by excessive secretion of parathyroid hormone from parathyroid adenoma, hyperplasia, or malignancy. The clinical symptoms of the condition are those of hypercalcemia. Although the lesions are commonly located in the neck region, in about 1–2 % of cases, the lesions are ectopically located within the mediastinum, where surgical excision using the cervical approach is difficult. The principal treatment of the condition is surgical excision of the lesion. However, some patients require additional surgery because of recurrence due to intraoperative dissemination. Therefore, safe and accurate excision is essential for the treatment. We reviewed the surgical treatment used at our institution for mediastinal parathyroid adenoma that caused primary hyperparathyroidism.MethodThe subjects were four patients with primary hyperparathyroidism due to mediastinal parathyroid adenoma who underwent surgery at our institution within a period of 10 years, between January 2005 and December 2014. All of the patients were female, with a mean age of 64.5 years (range, 55–74 years). The examined variables included background factors, clinical condition, surgical method, and clinical outcome.ResultIn all of the patients, primary hyperparathyroidism was detected with symptoms of hypercalcemia. Laboratory tests revealed a mean serum calcium level of 11.85 mg/dL (range, 11.2–13.2 mg/dL) and a mean parathyroid hormone (intact PTH) level of 304.8 pg/mL (range, 126–586 pg/mL), indicating elevated levels for all patients. Chest computed tomography (CT) revealed tumors with a mean diameter of 2.8 cm (range, 10–45 mm) in the anterior mediastinum in all of the patients. On 99mTC-methoxy isobutyl isonitrile (MIBI) scintigraphy, abnormal accumulation was observed in all of the patients. Regarding the surgical methods, median sternotomy was used for three cases and upper partial sternotomy was used for one case. The surgery was safely and accurately performed, without postoperative complications. After surgery, the serum calcium levels immediately returned to normal and the symptoms improved.ConclusionWe performed excision safely and accurately in all of the patients. In tumor identification, 99mTC-MIBI scintigraphy was useful. Accurate tumor identification and selection of the optimal surgical method are important for prevention of recurrence due to intraoperative dissemination.

Perfusion and metabolic scintigraphy with (123)I-BMIPP in prognosis of cardiac resynchronization therapy in patients with dilated cardiomyopathy.

The objective of the study was to investigate the left ventricular (LV) myocardial perfusion and metabolism in patients with idiopathic dilated cardiomyopathy (DCM) and to identify the scintigraphic predictors of the efficacy of cardiac resynchronization therapy (CRT). The study comprised 63 patients with DCM and severe heart failure (NYHA class III-IV). Before CRT, all patients received gamma-scintigraphy with (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) and with (123)I-β-methyl-iodophenyl pentadecanoic acid ((123)I-BMIPP) for evaluation of myocardial perfusion and metabolism, respectively. Before and after 6months of CRT, all patients underwent echocardiography study to assess cardiac hemodynamics. After 6months of CRT, patients were divided into two groups: group 1 comprised responders in whom LV end systolic volume (LVESV) decreased by ≥15% (n=39); group 2 comprised non-responders in whom LVESV decreased by <15% (n=24). Before CRT, LV pumping function did not significantly differ between groups. Significant differences were found in the following preoperative scintigraphic parameters: myocardial perfusion defect size [7.4% (5.9; 13.2)% and 11.8 (8.8; 16.2)%, p<0.05] and metabolic defect size [7.4 (4.4; 14.7)% and 8.8 (8.8; 17.6)%, p<0.05]. Metabolic scintigraphy showed greater diagnostic efficacy in determining the indications for CRT compared with perfusion scintigraphy [areas under the ROC curves (AUC) of 0.722 and 0.612, respectively]. The best metabolic defect size threshold value of 7.35% predicted CRT efficacy with the sensitivity and specificity rates of 77.8 and 66.7%, respectively. Data of metabolic scintigraphy may be useful for the integrated prediction of CRT efficacy.

Effect of trifluoperazine on Tc-99m sestamibi uptake in patients with advanced nonsmall cell lung cancer.

Objective:The aim of this study was to investigate whether there is an effect of trifluoperazine on Tc-99m methoxyisobutylisonitrile (MIBI) uptake in patients with advanced nonsmall cell lung cancer (NCLC).Materials and Methods:A total of 23 patients with biopsy-proven advanced NCLC who had no previous history of chemo-radiotherapy, underwent baseline dual phase planar, single photon emission computed tomography and whole body Tc-99m MIBI scintigraphy performed at 20 and 120 min. After oral administration of trifluoperazine (5 mg, 2 times a day, for 5 days), dual phase Tc-99m MIBI scintigraphy was repeated. For each patient, and for both studies, regions of interest were drawn over the tumor area (T) and over the normal lung area (L) on the contralateral side in transverse slices where tumor was visualized clearly. Then, early and delayed T/L ratios and washout rate (WR) were calculated.Results:Tc-99m MIBI was accumulated in the cancer tissue in all of the patients. Delayed ratio after the oral administration of trifluoperazine (DR2) was significantly higher (P = 0.039) than delayed ratio before trifluoperazine (DR1). We found no significant differences of early ratio before trifluoperazine (ER1) and early ratio after trifluoperazine (ER2), and washout rate before (WR1) and washout rate after trifluoperazine (WR2).Conclusion:In patients with advanced NCLC, trifluoperazine treatment in addition to chemotherapy might be useful. However, our results need to be confirmed in larger series of patients.

Abstract 19312: Multiplexed Images of the Heart Provide Novel Functional Information to Guide Invasive Procedures: A Review of the Initial Case Series

Introduction: The novel, high sensitivity and dedicated cardiac camera (D-SPECT, Spectrum Dynamics) allows single or dual tracer studies to add functional information to 3D DICOM image information from CT or CMR. Information consists of either perfusion information (from (technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI, for perfusion) and/or sympathetic nnervation information using meta-iodobenzylguanidine (mIBG). Merging these 3D images with invasive 3D electroanatomical maps (EAM) offers image integration on a function rather than geometrical level alone. These fused 3D images can be combined with EAM to guide ablation procedures for either atrial or ventricular arrhythmias. Methods: A total of 23 patients (15 male, mean age 59.9 yrs) underwent either single iodine-123 mIBG (n=10, for sympathetic innervation) or dual tracer (n= 13, mIBG+MIBI, for perfusion) imaging and the acquired information was fused with the 3D cCT or CMR using a custom-made software. Results: Twenty out of 23 patients underwent invasive electrophysiology studies which targeted either atrial or ventricular arrhythmias. During the atrial arrhythmia procedures, high uptake sites for mIBG was correlated to positive effect of high frequency stimulation (=transient prolongation of AV nodal conduction) and thereby confirming ganglionated plexi which were targeted in addition to the standard ablation. Patients with ventricular arrhythmia, low amplitude voltage mapping showed good correlation to the perfusion scar imaging, thereby serving as a substrate map even in patients with implantable devices. Interestingly, regions of mismatch where identified which proved to be pro-arrhythmogenic during EP study in the 4/6 patients who underwent ventricular tachycardia (VT) ablation. Conclusion: The combination of innervation (by mIBG) and perfusion (by MIBI) nuclear imaging in addition to the 3D cCT or CMR imaging provides a novel type of “road map” information for complex arrhythmia ablation by providing a region of mismatch of innervation and perfusion. This provides a novel substrate information even in the presence of implantable devices.

Combined Tc-99m sesta MIBI scintigraphy and Ultrasonography in preoperative detection and localization of parathyroid adenoma

PurposeTo evaluate the role of combined high resolution ultrasonography and technetium Tc-99m methoxyisobutylisonitrile (MIBI) parathyroid scintigraphy in preoperative detection and localization of parathyroid adenoma, for better operative outcome. Patients and methods40 patients were included in this study, 25 of them were females and 15 were males, with age ranging between 31 and 75 (mean 46±15). All patients presented with some of symptoms of hyperparathyroidism with venous blood sampling showed elevated parathyroid hormone (PTH). Parathyroid imaging was evaluated by ultrasonography, double phase Tc-99m MIBI parathyroid scintigraphy with surgical findings and results of clinical follow-up as a reference standard. ResultsAmong the 40 patients, Ultrasonography correctly identified 35 adenomas (87.5%) and MIBI scintigraphy identified 34 adenomas (85%), but when both modalities were applied together, 37 adenomas were correctly detected (92.5%).Minimally invasive parathyroidectomy under local anesthesia with unilateral incision was successfully performed in 34 (85%) patients. ConclusionsAccurate localization of adenomas should be obtained prior to surgery for minimal invasive surgical procedure. In this study, combined ultrasonography and Tc-99m MIBI improved localization of parathyroid adenomas.

SPECT-CT in Radiotherapy Planning, with Main Reference to Patients with Breast Cancer.

The aim of modern intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) is to define the target areas including the smallest non-invaded margins, thus reducing the radiation dose to radiosensitive organs. To reach this goal, these methods require a more precise target delineation by imaging to better define the viable part of the tumor. Image-guided selection and demarcation of Gross Tumor Volume (GTV), Clinical Target Volume (CTV) and Organs at Risk (OAR) are the main steps to reach a satisfactory radiation treatment plan. Hybrid machines, such as PET-CT, SPECT-CT and, more recently, PET-MRI, may significantly increase diagnostic accuracy improving either sensitivity and specificity achievable alone by the single constituents of the hybrid tools. While the implementation contribution of PET-CT in radiotherapy, with respect to CT stand alone, has been extensively and successfully investigated, few papers have been at present written on the possible role of SPECT-CT for the same purpose. With an identical contribution to CT, SPECT may give similar information with respect to PET, when suitable radiopharmaceuticals are available. In particular, SPECT may provide additional information to CT, better defining the viable tumor mass; as a consequence, a more effective delineation of the GTV, saving the maximum normal tissue as possible, may be allowed. In this paper, we review some of the most important applications of SPECT-CT in oncology, as a premise to its possible utilization in tumor target definition in radiotherapy. In particular, we discuss sentinel lymph node (SLN) detection, tumor imaging with cationic lipophilic radiotracers, as (99m)Tc-methoxyisobutylisonitrile (MIBI) and (99m)Tc-tetrofosmin (TF) in breast cancer, thymoma, and lung cancer, (99m)Tcmethylene diphosphonate (MDP) for bone scan, (131)Iodine and (123)Iodine in differentiated thyroid cancer (DTC), as useful methods to optimize GTV and CTV definition. A reflection on the possible role in radiotherapy of other radiotracers labeled with gamma emitters, such as In-111 pentreotide has also been included.

Diagnostic performance of myocardial perfusion single-photon emission computed tomography with attenuation correction.

Myocardial perfusion single-photon emission computed tomography (SPECT) is one of the basic tools used for the purpose of diagnosis of coronary artery disease (CAD), prognosis of its unfavourable consequences, and evaluation of therapy effectiveness. However, its efficacy is compromised by a relatively low specificity of detection of perfusion defects, which is attributed to attenuation of gamma rays inside the patient's body, causing artefacts erroneously taken for perfusion defects. It is expected that attenuation correction (AC) could eliminate such artefacts. To evaluate whether visual, semi-quantitative analysis of attenuation-corrected myocardial perfusion imaging provides an advantage over a non-corrected study. A retrospective study applying AC was performed in 107 patients who had coronary angiography within three months. Patients underwent a stress/rest Tc-99m methoxyisobutylisonitrile (MIBI, POLATOM) double day SPECT/CT myocardial perfusion imaging. Images were analysed by two experienced nuclear medicine specialists (a consensus) applying a visual semiquantitative method. Coronary angiography findings were used as a reference for the analysis of diagnostic performance of myocardial perfusion study protocols. AC increased the specificity of detection of CAD in the whole group of patients from 63% to 86% (p = 0.0005), with a slight reduction in sensitivity (from 83% to 79%). The improved specificity was also noted in subgroups of male and female patients. Accuracy in the whole group of patients increased from 71% to 83% (p = 0.01). AC improved the specificity and accuracy of the method in the detection of perfusion defects in the right coronary artery (RCA) area from 73% to 88% (p = 0.005) and from 74% to 83% (p = 0.04), respectively, and the accuracy of the method in the left anterior descending (LAD) artery area from 79% to 87% (p = 0.043). It also reduced the number of ambiguous results of the study. AC improved the diagnostic performance of myocardial perfusion study in the detection of CAD and identification of critically stenosed LAD and RCA vessels, with enhanced comfort of study interpretation.

Use of Autoleukocyte, Labelled with &lt;sup&gt;99m&lt;/sup&gt;Tc-Exametazine for Evaluation of Inflammatory Changes in Myocardium

Our purpose was to study possibilities of autoleukocyte, labelled in vitro with 99m Tc-exametazine (99m Tc-HMPAO), in evaluation of inflammatory changes of myocardium at patients with persistent form of atrial fibrillation (AF).We examined 30 patients with idiopathic persistent form of AF. For identification of the inflammatory areas in a myocardium before ablation scintigraphy (SPECT) 99mTc-HMPAO – leucocytes was carried out. Upon completion of scanning a perfusion scintigraphy of a myocardium with a 99mTc-methoxyisobutyl isonitrile (99mTc-MIBI) (‘Tehnetril, 99mTc’, JSC Diamed, Russia) in rest under the standard protocol was carried out. Pathologic accumulation of 99mTc-HMPAO-leukocytes in a myocardium was revealed at 6 (20%) of the examined patients. Sensitivity of SPECT with 99mTc-HMPAO-leukocytes in diagnostics of inflammatory changes of a myocardium, according to our data, was - 80%, specificity - 92%, diagnostic accuracy - 90%.

Longitudinal time-dependent effects of irradiation on multidrug resistance in a non-small lung cancer cell line.

Multidrug resistance (MDR) in cancer is known to decrease the therapeutic efficacy of chemotherapy. The effects of irradiation on MDR in cancer cells remain unclear. Tc-99m methoxyisobutylisonitrile (MIBI) exhibits the same ATP-binding cassette (ABC) transporter kinetics as the chemotherapeutic compound doxorubicin. In this study, we investigated the synergistic effects of chemotherapeutics and irradiation [0 Gy: C (control) group; 3, 6, 9, 12 Gy: I (irradiation) group] in the human non-small lung cancer cell line H1299 exhibiting MDR, on MIBI and doxorubicin ABC transporter kinetics, in vitro and in vivo, respectively. In vitro, inhibition of H1299 cell proliferation by irradiation was found to be irradiation dose dependent. The degree and duration of MDR inhibition in vitro in H1299 were also dose dependent. In the cells of both the C group and 3-Gy I group, no significant difference of MIBI accumulation was observed. In the 6-Gy I group, a higher MIBI accumulation was observed at only 7 days after irradiation relative to the C group. A higher MIBI accumulation in the 9- and 12-Gy I groups with a significant difference from the C group was observed at 4 to 14 days after irradiation. A significant negative correlation between intracellular MIBI accumulation and cell replication was found. In vivo, high accumulation and retention of doxorubicin were observed in irradiated tumors in the H1299 xenograft mice group at 4 to 14 days after 9-Gy irradiation compared with the control mice group. These results provide evidence for a synergistic effect of concurrent chemotherapy and radiotherapy.