Optimization, Realization and Quality Assessment of Arc-Modulated Cone Beam Therapy

Advanced radiation therapy techniques rely on a modulation of the fluence fields to optimize the clinical benefit of the treatment. This increased flexibility for intensity-modulated radiation therapy (IMRT) in comparison to conventional techniques allows the realization of excellent dose distributions. However, the advantage of superior dose distributions for IMRT usually requires an increased treatment time. A dose delivery technique with the potential to overcome this problem without impairing the treatment quality is dynamic rotation therapy in a single arc. This technique uses dynamic field shaping with a multileaf collimator (MLC) and a variable dose rate of the linac during irradiation to conform the dose distribution to the target volume. This thesis introduces an optimization concept for dynamic rotation therapy with variable dose rate, called arc-modulated cone beam therapy (AMCBT), that also accounts for all practical limitations of this approach imposed by the dose delivery hardware. This optimization algorithm is applied to assess the clinical potential of AMCBT via comparative treatment planning studies. Finally, a first realization of AMCBT based on a Siemens ArtisteTM linac equipped with a dynamic MLC was developed and investigated