Orbital masses: the usefulness of diffusion-weighted imaging in lesion categorization.

INTRODUCTION: Diffusion-weighted imaging (DWI) produces contrast among different kinds of tissues according to their diffusibility characteristics. The purpose of our study was to evaluate the role of DWI including measurement of apparent diffusion coefficient (ADC) values in recognizing benignancy or malignancy of orbital masses. METHODS: A total of 39 orbital masses were evaluated visually for signal characteristics on DWI and ADC maps. ADC values were calculated for each lesion. Visual signal characteristics were compared using the Fisher exact test. Receiver operating characteristic (ROC) analysis was carried out to determine sensitivity and specificity for distinguishing malignant from benign lesions using ADC values. The Mann-Whitney U test was applied to compare the ADC values between orbital lymphomas and idiopathic orbital inflammatory (IOI) lesions, and between optic nerve sheath meningiomas and gliomas. RESULTS: Visual assessment revealed no significant difference between benign and malignant lesions on DWI (p-value = 0.66). However, visual assessment of ADC maps revealed a statistically significant (p-value ≤ 0.0001) between benign and malignant lesions. ROC analysis showed a sensitivity of 83.33 % and a specificity of 85.71 % when using an optimal cut off ADC value of 0.84 × 10(-3) mm(2)/s for differentiating malignant from benign lesions. Significant differences in mean ADC values were observed between lymphomas and IOI lesions (p-value = 0.05), and between optic nerve sheath meningiomas and gliomas (p-value = 0.03). CONCLUSION: DWI is useful for differentiating malignant and benign orbital tumors if accompanied by visual assessment of ADC maps and ADC value calculations.

Treatment with peginterferon plus ribavirin vs. interferon plus ribavirin for 48 weeks in Chinese patients with chronic hepatitis C.

INTRODUCTION: Virological responses to interferon (IFN) treatment for chronic hepatitis C (CHC) have been found to be correlated with racial differences. Furthermore, higher sustained virological response (SVR) rates were obtained in many randomised clinical trials (RCT) in Caucasian patients with CHC after treating with peg-IFN than those with IFN. However, it is not clear whether this conclusion can be adapted to patients of Chinese descent. METHODS: A search of MEDLINE and China National Knowledge Infrastructure between 1966 and 2008 was performed. Trials comparing the use of peg-IFN plus ribavirin vs. IFN plus ribavirin in treating Chinese patients with CHC were assessed. RESULTS: Of the 94 studies screened, seven RCTs including 398 patients (peg-IFN therapy 232, IFN therapy 166) were analysed. The SVRs obtained in patients treated with peg-IFN plus ribavirin were significantly higher than in patients treated with IFN plus ribavirin [70% vs. 35%, relative risk, 1.76; 95% confidence interval: 1.21-2.56; p (0.01)]. Withdrawal rates were similar between patients treated with peg-IFN plus ribavirin and IFN plus ribavirin. CONCLUSION: Chinese patients with CHC also have a greater likelihood of achieving an SVR with peg-IFN plus ribavirin.