Functional Magnetic Resonance Imaging in the Diagnosis of Locally Recurrent Prostate Cancer: Are All Pulse Sequences Helpful?

OBJECTIVE: To perform a meta-analysis to quantitatively assess functional magnetic resonance imaging (MRI) in the diagnosis of locally recurrent prostate cancer. MATERIALS AND METHODS: A comprehensive search of the PubMed, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews was conducted from January 1, 1995 to December 31, 2016. Diagnostic accuracy was quantitatively pooled for all studies by using hierarchical logistic regression modeling, including bivariate modeling and hierarchical summary receiver operating characteristic (HSROC) curves (AUCs). The Z test was used to determine whether adding functional MRI to T2-weighted imaging (T2WI) results in significantly increased diagnostic sensitivity and specificity. RESULTS: Meta-analysis of 13 studies involving 826 patients who underwent radical prostatectomy showed a pooled sensitivity and specificity of 91%, and the AUC was 0.96. Meta-analysis of 7 studies involving 329 patients who underwent radiotherapy showed a pooled sensitivity of 80% and specificity of 81%, and the AUC was 0.88. Meta-analysis of 11 studies reporting 1669 sextant biopsies from patients who underwent radiotherapy showed a pooled sensitivity of 54% and specificity of 91%, and the AUC was 0.85. Sensitivity after radiotherapy was significantly higher when diffusion-weighted MRI data were combined with T2WI than when only T2WI results were used. This was true when meta-analysis was performed on a per-patient basis (p = 0.027) or per sextant biopsy (p = 0.046). A similar result was found when ¹H-magnetic resonance spectroscopy (¹H-MRS) data were combined with T2WI and sextant biopsy was the unit of analysis (p = 0.036). CONCLUSION: Functional MRI data may not strengthen the ability of T2WI to detect locally recurrent prostate cancer in patients who have undergone radical prostatectomy. By contrast, diffusion-weight MRI and ¹H-MRS data may improve the sensitivity of T2WI for patients who have undergone radiotherapy.

Exhaled hydrogen sulfide in patients with chronic obstructive pulmonary disease and its correlation with exhaled nitric oxide / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Exhaled nitric oxide (NO) is a noninvasive biomarker of airway inflammation in pulmonary diseases. Hydrogen sulfide (H2S), as the third member of the gasotransmitter family, is involved in the pathophysiological process in lung diseases. H2S also exists in exhaled breath and can be sampled non-invasively. The study investigated the level of exhaled H2S in patients with chronic obstructive pulmonary disease (COPD) and its correlation with exhaled NO.</p><p><b>METHODS</b>Levels of exhaled NO and H2S, lung function, and cell differential counts in induced sputum were studied in 19 patients with acute exacerbation of COPD (AECOPD), 19 patients with stable COPD and seven healthy smoke controls.</p><p><b>RESULTS</b>Exhaled H2S levels were similar in patients with AECOPD (10.0 parts per billion (ppb), 8.0-13.0 ppb), stable COPD (10.0 ppb, 9.0-12.0 ppb), and healthy controls (9.0 ppb, 8.0-16.0 ppb) (P > 0.05). Exhaled NO levels were similar in patients with AECOPD (155.0 ppb, 129.0-190.0 ppb), stable COPD (154.0 ppb, 133.0-175.0 ppb) and healthy controls (165.0 ppb, 112.0-188.0 ppb) (P > 0.05). Exhaled H2S levels correlated positively with exhaled NO in all healthy controls and patients with COPD (r=0.467, P < 0.01). No significant correlation was found between the exhaled H2S level and percentage of predicted FEV1 (P > 0.05) and proportion of different cell types in induced sputum (P > 0.05).</p><p><b>CONCLUSIONS</b>There is a correlation between exhaled H2S and exhaled NO. The role of exhaled H2S in airway inflammation in COPD still needs further investigation.</p>