Reducing the dose of gadolinium-based contrast agents for DCE-MRI guided SBRT: The effects on inter and intra observer variability for preoperative target volume delineation in early stage breast cancer patients.

BACKGROUND AND PURPOSE: This study aimed to determine the effects of reducing the dose of contrast agent (CA) in a DCE-MRI scan on inter- and intra-observer variability in the context of MRI-guided target volume delineation for stereotactic body radiation therapy of early stage breast cancer patients. This is in hopes of reducing risks to patients due to findings of residual CA in brain and bone. MATERIALS AND METHODS: Twenty-three patients receiving neoadjuvant radiation therapy were enrolled. Five observers delineated the gross target volume (GTV) using DCE-MRI for guidance. 14/23 patients received the full clinical dose of CA and 9/23 received half. Clinical target volumes (CTV) were created through a 0.5 cm uniform expansion. Several metrics were used to quantify the inter and intra-observer reliability including differences in delineation volume and the reliability coefficient. RESULTS: There were no significant differences in the volume, though half contrast patients had a lower median for both the GTV and CTV (difference of 0.26 cm3 and 1.27 cm3, respectively). All indicated a high degree of agreement between and within observers for both dose groups. However, the full dose group had a greater inter-observer variability, most likely due to the full CA causing more pronounced enhancement in the periphery. CONCLUSIONS: Reducing the dose of contrast agent did not significantly alter inter- or intra-observer variability. These results have prompted our centre to reduce the dose of gadolinium in all patients enrolled in the SIGNAL trial.

Research for universal health coverage: World health report 2013

 

Universal health coverage ensures everyone has access to the health services they need without suffering financial hardship as a result. In December 2012, a UN resolution was passed encouraging governments to move towards providing universal access to affordable and quality health care services. As countries move towards it, common challenges are emerging - challenges to which research can help provide answers.

The World health report: research for universal health coverage focuses on the importance of research in advancing progress towards universal health coverage. In addition, it identifies the benefits of increased investment in health research by low- and middle-income countries using case studies from around the world, and proposes ways to further strengthen this type of research.

Long-term magnetic resonance imaging/spectroscopy study of cariporide in a canine cardiac ischemia/reperfusion model.

Using both 31P and 1H cardiac magnetic resonance techniques, it is possible to monitor the functional (ejection fraction [EF]) and biochemical (pH) status of the heart following a reperfused ischemic insult. This study assessed the effects of Na+/H+ exchange inhibition with cariporide in a closed-chest canine ischemia/reperfusion model. Dogs received 1-mg/kg cariporide treatments for 3 days after occlusion, but were monitored for 10 days. Baseline intracellular pH (+/-SEM) for the control and treated groups were 7.10 +/- 0.03 and 7.14 +/- 0.04, respectively, and dropped to 6.25 +/- 0.08 and 6.38 +/- 0.08 during occlusion. There was a significant increase in pH from occlusion to early reperfusion in the control group (P = 0.03) but, during the same time period, this increase was not seen in the cariporide group. There was a significant (P = 0.01) drug interaction in recovery of EF over the 10-day protocol. Individual time-point analysis revealed significant differences at immediate reperfusion through day 3 (73.9% +/- 2.5%, 84.5% +/- 3.1%; baseline normalized EF controls and cariporide, respectively). Neither pH nor EF measurements were significantly different between the groups at day 10. Despite early functional and metabolic benefits, infarct size, as measured at day 10, was 13.2% +/- 2.2% for the controls and 11.8% +/- 2.3% for the cariporide group (NS). Thus there were no long-term cariporide functional or biochemical benefits.