As promised, I have now received the requested info from Mr J. Palmer, Consultant Neurosurgeon, Derriford Hospital, Plymouth, England who is the only practitioner offering the 'BrainLAB M3' treatment within the UK albeit it is apparently offered at approx 70 medical centres worldwide.
In brief, 'BrainLAB M3' is the name of a device (also known as 'shaped beam radiosurgery) that changes the radiation beam from a linear accelerator to focus onto a tumour target to the shape of the beam. In essence the 'shaped beam radiosurgery' delivers equivalent treatment to that provided by GK and is a straightforward alternative. The main difference between the two options is that.'BrainLAB M3' shapes the beam of radiosurgery to that of the tumour whereas GK builds up a number of overlapping spheres of radiation to map the tumour.
In the UK the cost of the treatment is £10,000 ($18.810.96) and has been offered for only 1 year to a total of 60 patients and therefore there is no data available on the overall success rate but apparently, worldwide, growth arrest of 90% is anticipated and of the remaining 10%, half (5%) are expected to undergo subsequent surgical removal of the AN.
The long term results are believed to be similar to GK and as there is apparently no evidence to indicate any distinct benefit applicable to the 'BrainLAB M3' process I would personally opt for any proposed stereotactic radiosurgery to be undertaken with the tried and tested GK system.
Regards
Derek