First, I'm sorry it didn't work out for you as planned, it sucks.
Last year there were three programs in the scramble. The University of Louisville filled their spot the first or second day of the scramble. The other two U. of Kentucky and U. of Kansas just took in applications and sent out interview invites after the scramble period and signed candidates like a month after match day. Basically there is not a lot you can do just submit to the open programs via ERAS and if you have a rad onc faculty member willing to call the open programs on your behalf that always helps. I don't know if this will happen this year but over the past 8 months maybe 9 spots opened up outside the match to start this July (Maryland, Cincinnati, San Dieago, Mississippi, Baylor, Nebraska, Methodist come to mind).