OC-0387: the UK HeartSpare Study (stage II): Multicentre Evaluation of a Voluntary Breath-Hold Technique

S1863rd ESTRO Forum 2015 being performed in low dose rates.The MU used for the FFF plans are higher in the Varian/Novalis-Eclipse combination; this is not seen for Elekta -Pinnacle.In general Eclipse used more MU than Pinnacle.The beam-on times are significantly reduced and the largest gain is seen for Elekta-Pinnacle.Conclusions: FFF can be used for SBRT planning and delivery of accurate dose, independent of the specific combination of accelerator vendor and treatment planning system.The different combinations have different specific issues.Future perspective is to add the TomoTherapy-Hi Art combination to the study.