The value of 18F-fluorodeoxyglucose positron emission tomography for prediction of treatment response in gastrointestinal stromal tumors: a systematic review and metaanalysis

Background: Early detection of response to treatment is critically important in gastrointestinal stromal tumors (GIST). Therefore, the present systematic review and meta-analysis assessed the value of 18f-fluorodeoxyglucose positron emission tomography (18FDG– PET) on prediction of therapeutic response of GIST patients to systemic treatments. Methods: The literature search was conducted using PubMed, SCOPUS, Cochrane, and Google Scholar databases, and review article references. Eligible articles were defined as studies included confirmed GIST patients who underwent 18FDG–PET as well as assessing the screening role of it. Results: Finally, 21 relevant articles were included. The analysis showed the pooled sensitivity and specificity of 18FDG–PET in evaluation of response to treatment of GIST patient were 0.90 (95% CI: 0.85–0.94; I 2 = 52.59, P = 0.001) and 0.62 (95% CI: 0.49–0.75; I 2 = 69.7, P = 0.001), respectively. In addition, the pooled prognostic odds ratio of 18FDG–PET for was 14.99 (95% CI, 6.42–34.99; I 2 = 100.0, P < 0.001). The Meta regression showed that sensitivity of 18FDG-PET was higher if the sample size of study was equal or more than 30 cases (sensitivity = 0.93; 95% CI: 0.89–0.97), when using PET/CT (sensitivity = 0.92; 95% CI: 0.89–0.97), and self-design criteria (sensitivity = 0.93; 95% CI: 0.87–1.0). Conclusion: The present meta-analysis showed 18FDG–PET has a significant value in predicting treatment response in GIST patients

A simple way to distinguish bed clothing contamination in a whole body bone scan: a case report

Whole body bone scan with Technetium-99m MDP (methylene diphosphate) can detect bony lesions due to altered osteoblastic activity

Frequency and severity of myocardial perfusion abnormalities using Tc-99m MIBI SPECT in cardiac syndrome X

BACKGROUND: Cardiac syndrome X is defined by a typical angina pectoris with normal or near normal (stenosis <40%) coronary angiogram with or without electrocardiogram (ECG) change or atypical angina pectoris with normal or near normal coronary angiogram plus a positive none-invasive test (exercise tolerance test or myocardial perfusion scan) with or without ECG change. Studies with myocardial perfusion imaging on this syndrome have indicated some abnormal perfusion scan. We evaluated the role of myocardial perfusion imaging (MPI) and also the severity and extent of perfusion abnormality using Tc-99m MIBI Single Photon Emission Computed Tomography (SPECT) in these patients. METHODS: The study group consisted of 36 patients with cardiac syndrome X. The semiquantitative perfusion analysis was performed using exercise Tc-99m MIBI SPECT. The MPI results were analyzed by the number, location and severity of perfusion defects. RESULTS: Abnormal perfusion defects were detected in 13 (36.10%) cases, while the remaining 23 (63.90%) had normal cardiac imaging. Five of 13 (38.4%) abnormal studies showed multiple perfusion defects. The defects were localized in the apex in 3, apical segments in 4, midventricular segments in 12 and basal segments in 6 cases. Fourteen (56%) of all abnormal segments revealed mild, 7(28%) moderate and 4 (16%) severe reduction of tracer uptake. No fixed defects were identified. The vessel territories were approximately the same in all subjects. The Exercise treadmill test (ETT) was positive in 25(69%) and negative in 11(30%) patients. There was no consistent pattern as related to the extent of MPI defects or exercise test results. CONCLUSION: Our study suggests that multiple perfusion abnormalities with different levels of severity are common in cardiac syndrome X, with more than 30 % of these patients having at least one abnormal perfusion segment. Our findings suggest that in these patients microvascular angina is probably more common than is generally believed

Assessment of genetic mutations in the XRCC2 coding region by high resolution melting curve analysis and the risk of differentiated thyroid carcinoma in Iran

Homologous recombination (HR) is the major pathway for repairing double strand breaks (DSBs) in eukaryotes and XRCC2 is an essential component of the HR repair machinery. To evaluate the potential role of mutations in gene repair by HR in individuals susceptible to differentiated thyroid carcinoma (DTC) we used high resolution melting (HRM) analysis, a recently introduced method for detecting mutations, to examine the entire XRCC2 coding region in an Iranian population. HRM analysis was used to screen for mutations in three XRCC2 coding regions in 50 patients and 50 controls. There was no variation in the HRM curves obtained from the analysis of exons 1 and 2 in the case and control groups. In exon 3, an Arg188His polymorphism (rs3218536) was detected as a new melting curve group (OR: 1.46; 95%CI: 0.432-4.969; p = 0.38) compared with the normal melting curve. We also found a new Ser150Arg polymorphism in exon 3 of the control group. These findings suggest that genetic variations in the XRCC2 coding region have no potential effects on susceptibility to DTC. However, further studies with larger populations are required to confirm this conclusion

Changes in salivary gland function following radioiodine therapy of thyroid diseases: A comparison of high-dose therapy for thyroid cancer and low-dose therapy for benign thyroid disease

ABSTRACT Introduction: High-dose radioactive iodine therapy in differentiated thyroid cancer (DTC) may adversely affect the salivary gland function. This study is aimed to evaluate the effect of radioactive iodine (RAI) with dose of 100 mCi in DTC patients compared to lower doses of less than 30 mCi in hyperthyroid cases. Methods: Fifty four patients (13 men and 41 women) age: 42.3±14.3 (21-71) years were enrolled in the study. Twenty seven hyperthyroid cases received less than 30 mCi of I-131 for the treatment, and 27 DTC patients were treated with 100 mCi of I-131. All patients underwent Tc-99m pertechnetate scintigraphy before and three months after radioiodine therapy. Salivary gland excretion fractions (EF) were compared between groups. A decrease of more than 5% in EF was considered significant. Results: The total frequency of salivary dysfunction was 41.7%. In patients received a dosage of 100 mCi of I-131, this frequency was 49.1%, while with less than 30 mCi, it was 34.3% (p&lt;0.01). The right parotid gland was affected more than the left following 100 mCi treatment. Risk ratio of salivary gland involvement in high-dose versus low-dose group was significant (risk ratio=1.04-1.98, CI (95%); p=0.019). However, there was no significant difference in symptom presentation, i.e. xerostomia between two groups. Conclusion: RAI therapy may cause salivary gland dysfunction and this effect is more frequent in DTC patients with higher dose of 100 mCi compared to hyperthyroid cases with lower doses of less than 30 mCi

CT and PET Image Registration: Application to Thorax Area

Accurate attenuation correction of emission data is mandatory for quantitative analysis of PET images. One of the main concerns in CT-based attenuation correction (CTAC) of PET data in multimodality PET/CT imaging is misalignment occurred due to respiratory artifact between PET and CT images. In this paper a combined method which is simple and fast is proposed for registration of PET and CT data to correct the effect of this artifact. The algorithm is composed of two step: First step is meant to reduce the noise by applying an adaptive gradient anistropic diffusion filter then using Iterative closest point (ICP) registration method in order to obtain initial estimation to ensure fast and accurate convergence of the algorithm. At the second step, the respiratory related artifact of PET images is greatly reduced by employing Free Form Deformation algorithm based on B-spline which provides more accurate adaptive transformation to align the imagesGodkänd; 2013; 20140217 (davkho

99m tc-Ubiquicidin [29-41], a Promising Radiopharmaceutical to Differentiate Orthopedic Implant Infections from Sterile Inflammation

Abstract Ubiquicidin (UBI) [29][30][31][32][33][34][35][36][37][38][39][40][41] is a synthetic cationic antimicrobial peptide that preferentially binds to bacterial cell membrane at the site of infection. We aimed to assess diagnostic value of Tc-UBI [29-41] was injected intravenously. A dynamic study followed by static whole body imaging at 30, 60 and 120 min post-radiotracer injection was acquired. Periprosthetic tissue culture was considered the closest test to a gold standard for diagnosing infections and scintigraphic scans were categorized as true-or false-positive and true-or false-negative, considering the bacterial culture as the gold standard. No adverse reaction was observed during or after the radiotracer injection days. There were five true positive, four true negative and no false positive and false negative scans. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were all calculated as 100%. We found a high diagnostic accuracy for 99m scintigraphy in differentiation of bacterial infection from sterile inflammation in suspected orthopedic implants. Therefore, Tc-UBI [29][30][31][32][33][34][35][36][37][38][39][40][41] scintigraphy might be potentially recommended as a safe and promising imaging modality in these settings. However, further studies on a larger number of patients and different pathologies are still needed