How would you approach dosing and constraints for a previously irradiated SNUC with a marginal recurrence with partial response after chemoradiation with disease currently involving the bilateral orbits?

I have considered hyperfractionation when I think an optic structure, particularly the nerves, will exceed mid-60s Gy. While the BID is not factored in and may be slightly influential, especially the tighter the gap, for an a/b of 3, 66/33 is eqd2-66 while 66/55 is eqd2-55. Granted, there is some lo...