Assessment of Mechanical Properties of Tissue in Breast Cancer-Related Lymphedema Using Ultrasound Elastography.

Breast cancer-related lymphedema is a consequence of a malfunctioning lymphatic drainage system resulting from surgery or some other form of treatment. In the initial stages, minor and reversible increases in the fluid volume of the arm are evident. As the stages progress over time, the underlying pathophysiology dramatically changes with an irreversible increase in arm volume most likely due to a chronic local inflammation leading to adipose tissue hypertrophy and fibrosis. Clinicians have subjective ways to stage the degree and severity such as the pitting test which entails manually comparing the elasticity of the affected and unaffected arms. Several imaging modalities can be used but ultrasound appears to be the most preferred because it is affordable, safe, and portable. Unfortunately, ultrasonography is not typically used for staging lymphedema, because the appearance of the affected and unaffected arms is similar in B-mode ultrasound images. However, novel ultrasound techniques have emerged, such as elastography, which may be able to identify changes in mechanical properties of the tissue related to detection and staging of lymphedema. This paper presents a novel technique to compare the mechanical properties of the affected and unaffected arms using quasi-static ultrasound elastography to provide an objective alternative to the current subjective assessment. Elastography is based on time delay estimation (TDE) from ultrasound images to infer displacement and mechanical properties of the tissue. We further introduce a novel method for TDE by incorporating higher order derivatives of the ultrasound data into a cost function and propose a novel optimization approach to efficiently minimize the cost function. This method works reliably with our challenging patient data. We collected radio frequency ultrasound data from both arms of seven patients with stage 2 lymphedema, at six different locations in each arm. The ratio of strain in skin, subcutaneous fat, and skeletal muscle divided by strain in the standoff gel pad was calculated in the unaffected and affected arms. The p -values using a Wilcoxon sign-rank test for the skin, subcutaneous fat, and skeletal muscle were 1.24×10-5 , 1.77×10-8 , and 8.11×10-7 respectively, showing differences between the unaffected and affected arms with a very high level of significance.

Prolonged treatment duration is required for successful Helicobacter pylori eradication with proton pump inhibitor triple therapy in Canada.

BACKGROUND: Traditional seven-day proton pump inhibitor triple therapy for Helicobacter pylori eradication has recently shown disappointing results outside of Canada. Prolonging therapy may be associated with poorer compliance and, hence, may not have a better outcome in a real-world setting. OBJECTIVE: To compare the outcomes of seven- and 14-day triple therapy for first-line treatment of H pylori infection in an effectiveness setting in Canada. METHODS: A total of 314 consecutive treatment-naive, adult H pylori-infected patients were allocated to either a seven- or 14-day triple therapy regimen, with a subgroup of 172 consecutive patients quasi-randomized to treatment according to date of visit. Eradication was confirmed using either urea breath test or gastric biopsies. Analysis was by intention to treat. RESULTS: Eradication was achieved in a higher proportion of patients who underwent 14-day versus seven-day treatment regimens (overall: 85% versus 70% [P≤0.001]; subgroup: 83% versus 64% [P≤0.01]). Although successful eradication was also associated with older age and a diagnosis of ulcer disease, multivariate analysis revealed only longer treatment duration and lack of yogurt ingestion as independent predictors of successful eradication. There was a trend toward reduced success in the latter years of the study. Side effects were similar in both groups and were not prevented by yogurt ingestion. CONCLUSIONS: The currently recommended duration of proton pump inhibitor triple therapy in Canada should be increased from seven to 14 days, the latter having achieved an excellent result in this particular real-world setting. Yogurt added no benefit. Further study is required to compare 10-day with 14-day treatment regimens.