Glioblastoma (GBM) is the most common primary malignant type of brain neoplasm in adults and carries a dismal prognosis. The current standard of care for GBM is surgical excision followed by radiation therapy (RT) with concurrent and adjuvant temozolomide-based chemotherapy (TMZ) by six additional cycles. In addition, antiangiogenic therapy with an antivascular endothelial growth factor (VEGF) agent has been used for recurrent glioblastoma. Over the last years, new posttreatment entities such as pseudoprogression and pseudoresponse have been recognized, apart from radiation necrosis. This review article focuses on the role of different imaging techniques such as conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), dynamic contrast enhancement (DCE-MRI) and dynamic susceptibility contrast (DSE-MRI) perfusion, magnetic resonance spectroscopy (MRS), and PET/SPECT in differentiation of such treatment-related changes from tumor recurrence.
Treatment for brain gliomas is a combined approach of surgery, radiation therapy and chemotherapy. Nevertheless, high-grade gliomas usually recur despite treatment. Ionizing radiation therapy to the central nervous system may cause post-radiation damage. Differentiation between post-irradiation necrosis and recurrent glioma on the basis of clinical signs and symptomatology has not been possible. Computed tomography (CT) and magnetic resonance imaging (MRI) suffer from significant limitations when applied to differentiate recurrent brain tumor from radiation necrosis. We reviewed the contribution of recent MRI techniques, single-photon emission CT and positron emission tomography to discriminate necrosis for glioma recurrence. We concluded that despite the progress being made, further research is needed to establish reliable imaging modalities that distinguish between true tumour progression and treatment-related necrosis.
Octreotide does not improve systemic hemodynamics in nonazotemic cirrhotic patients with ascites while it impairs renal function. On the other hand, the addition of midodrine can ameliorate the hyperdynamic circulation without inducing renal dysfunction in these patients.
Purpose
Gliomas constitute the most frequent primary brain tumors. Glioblastoma, the most common and malignant glioma in adults, has dismal prognosis with any current therapy. On the other hand, low-grade gliomas, the second most common type of gliomas, are potentially curative with appropriate treatment.
Methods
We conducted a meta-analysis to assess the performance of PET tracers with the best available evidence, namely, fluorodeoxyglucose (FDG), 11C-methionine (MET), and 18F-fluoroethyltyrosine (FET), in differentiating low- from high-grade gliomas.
Results
Twenty-three studies with a total of 994 participants were included in this meta-analysis. The pooled sensitivities of both MET PET and FET PET were found to be significantly higher than of FDG PET (94%, 88%, and 63% respectively, P < 0.001). The pooled specificity of FDG PET was found to be significantly greater compared with both MET PET and FET PET (89%, 55%, and 57%, respectively; P = 0.002). Fluorodeoxyglucose PET was superior in terms of higher positive likelihood ratio values compared with both FET PET and MET PET.
Conclusions
This meta-analysis indicated that both MET and FET were superior to FDG in terms of sensitivity for identifying glioma grade.
BackgroundPolymorphisms of the vitamin D receptor (VDR) gene have been linked to both multiple sclerosis (MS) and osteoporosis. We examined the frequency of the Taq-I and Bsm-I polymorphisms of the vitamin D receptor (VDR) gene in 69 patients with MS and 81 age and sex-matched healthy individuals. Genotyping of Taq-I (rs731236) and Bsm-I (rs1544410) was performed using TaqMan® SNP Genotyping Assay. All patients and controls had determination of body mass index (BMI), bone mineral density (BMD) and smoking history.ResultsThe mean age of patients was 39 ± 10.5 years compared to 38.7 ± 10.7 years of the controls (p = 0.86), the BMI was 24.8 ± 4.2 kg/m2 compared to 25.7 ± 4.8 kg/m2 of the controls (p = 0.23), the BMD in the lumbar spine 0.981 ± 0.15 compared to 1.025 ± 013 of the controls (p = 0.06) and the total hip BMD was 0.875 ± 0.14 compared to 0.969 ± 0.12 of the controls (p < 0.001). There were no differences of the Taq-I (TT, CT, CC) and Bsm-I genotypes (GG, GA, AA) and allelic frequencies between MS and control individuals. Multivariate analysis also failed to show any association of the Taq-I and Bsm-I polymorphisms and MS or sex, BMI, BMD and smoking history.ConclusionsThis study suggests that the Taq-I and Bsm-I polymorphisms of the VDR gene are not associated with MS risk, BMI or BMD in the Greek population studied.
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