Mitigating Respiratory Motion in Radiation Therapy: Rapid, Shallow, Non-invasive Mechanical Ventilation for Internal Thoracic Targets.

Purpose: Reducing respiratory motion during the delivery of radiation therapy reduces the volume of healthy tissues irradiated and may decrease radiation-induced toxicity. The purpose of this study was to assess the potential for rapid shallow non-invasive mechanical ventilation to reduce internal anatomy motion for radiation therapy purposes.

Methods And Materials: Ten healthy volunteers (mean age, 38 years; range, 22-54 years; 6 female and 4 male) were scanned using magnetic resonance imaging during normal breathing and at 2 ventilator-induced frequencies: 20 and 25 breaths per minute for 3 minutes.

Investigating the generalisation of an atlas-based synthetic-CT algorithm to another centre and MR scanner for prostate MR-only radiotherapy.

There is increasing interest in MR-only radiotherapy planning since it provides superb soft-tissue contrast without the registration uncertainties inherent in a CT-MR registration. However, MR images cannot readily provide the electron density information necessary for radiotherapy dose calculation. An algorithm which generates synthetic CTs for dose calculations from MR images of the prostate using an atlas of 3 T MR images has been previously reported by two of the authors.

The effect of variability in the powder/liquid ratio on the strength of zinc phosphate cement.

Aim. To investigate (a) variability in powder/liquid proportioning and (b) effect of variability on diametral tensile strength (DTS), in a zinc phosphate cement. Statistical analyses (α = 0.