Background and purposeIntroducing into practice a new carbon-fibre couch necessitates its evaluation with regard to the present clinical situation.Materials and methods
In this study, a geometric and dosimetric evaluation has been made for the Sinmed Mastercouch® as a replacement for the Elekta C-arm couch with Mylar®–tennis racket combination. Geometrically, feasible gantry angles with regard to collision and beam intersection were discriminated as function of isocentric table rotation for 10 treatment isocentres. Dosimetrically, the build-up distortion and attenuation by the aforementioned tabletops and a carbon-fibre tabletop of an Elekta Precise simulator was measured. Finally, the clinical implications of these influences were assessed for a 3-field prostate treatment in three configurations: Mastercouch®, C-arm couch and no-intersection situation.
Results
With regard to collision, the largest advantages are observed for the Mastercouch® with the Ω-shaped treatment module compared to the C-arm couch for isocentres located in the upper part of the body, thanks to its shape and the absence of any metal. Dosimetrically, one has to take into account the build-up loss and attenuation by beam intersection with Mastercouch® and the carbon-fibre edges of the tennis racket (C-arm couch). The clinical relevance of these dosimetric aspects depends on the dose delivered by the compromised beams.