Sorry to hear Damien. Not sure of the options either being IMRT radiation was just given, but a blogger here said he was doing something like 20 IMRT, and then 15 Protons, so it may be possible. I'm currently doing 25 Proton treatments at Procure in Somerset, NJ, and just finished my 15th treatment today, and hardly have redness. As mentioned previously, MSKCC, and five other top NYC hospitals, Beth Israel (Continium Health Care), Mt Sinai, NYU, NY Presbeterian, Montifiore are part of Procure center since October, and send patients there where each hospital has a RO there every Monday for patients like myself, but I'm at Beth Israel, so would be a different doctor than from MSKCC, but other doctors from Procure may see you in their absence, and did. I know you like MSKCC, they are not the only top ones in NYC, and I highly recommend seeing Dr. Harrison, at least for a consultation at Beth Israel. He worked at MSKCC for over ten years, and is world renowned. He is also a head and neck expert, an otoloaryncologist, and did my surgery for IORT, twice, with my ENT who did the dissections, IMRT, removed my carotid artery, and now sent me to Protons. There is no quit in this guy. MSKCC wouldn't even meet with me last year, but he did, and treated me.
Good luck with everything, and I hope for the best and best options.