Proton Beam funding refused by the NHS Funding board

When I received my results of my last MRI 3 weeks ago my oncologist recommended that I have proton beam treatment again
He felt that it was the correct retreatment and put me forward for funding via the NHS commissioning board
Three weeks later I hear that funding has been refused
I am awaiting the official letter but I am advised there is little likelihood of appeal

Also In the last week or so my oncologist has changed. He, ironically has gone to work at the UK proton centre in Manchester due to open in october 2018

My new oncologist was the one who called me and told me the news
She has suggested as an alternative treatment called gamma knife
She will see me in the new year to review the situation

I am now in limbo and unsure of the next steps - Are there grounds for appeal?
Can I look at private funding either in USA where I went before or cheaper but unknown alternatives like the proton centre in Prague

Lots to consider and agonise over

In the meantime I have a ticking time bomb tumor in my head