Fig. 2.

Screenshot obtained from GammaPlan version 11.1.1 treatment planning software containing volumetric T1-post contrast MRI brain images after upfront surgical debulking for a selected patient receiving fractionated radiosurgery with GammaKnife ICON. Outlined in red is the post-operative intended treatment volume as determined by fusion with pre-operative imaging as well as close collaboration with the neurosurgical team to determine residual disease versus post-operative changes (15.5 cc volume). Yellow and green represent the 50% and 20% isodose lines, respectively. Dose was prescribed to the 50% isodose line (yellow). As outlined, coverage of the treatment volume was 99% with a 58% selectivity and beam-on time of 12.1 min per fraction