Absorbed dose measurements in the build-up region of flattened versus unflattened megavoltage photon beams.

This study evaluated absorbed dose measurements in the build-up region of conventional (FF) versus flattening filter-free (FFF) photon beams. The absorbed dose in the build-up region of static 6 and 10MV FF and FFF beams was measured using radiochromic film and extrapolation chamber dosimetry for single beams with a variety of field sizes, shapes and positions relative to the central axis. Removing the flattening filter generally resulted in slightly higher relative build-up doses.

Hair-sparing whole brain radiotherapy with volumetric arc therapy in patients treated for brain metastases: dosimetric and clinical results of a phase II trial.

Purpose: To report the dosimetric results and impact of volumetric arc therapy (VMAT) on temporary alopecia and hair-loss related quality of life (QOL) in whole brain radiotherapy (WBRT).

Methods: The potential of VMAT-WBRT to reduce the dose to the hair follicles was assessed. A human cadaver was treated with both VMAT-WBRT and conventional opposed field (OF) WBRT, while the subcutaneously absorbed dose was measured by radiochromic films and calculated by the planning system.

Optimizing image acquisition settings for cone-beam computed tomography in supine and prone breast radiotherapy.

Volumetric discrepancies between cone-beam computed tomography (CBCT) and planning CT image sets were investigated for both prone and supine breast radiotherapy. A phantom study was performed in order to examine the artefacts' dependency on CBCT acquisition parameters and to minimize their effect on patient set-up accuracy.