I had my RT done privately at the Clatterbridge Private Clinic, part of the NHS Clatterbridge Cancer Centre on the Wirral. Paid for by work medical insurance. To be honest, the only real difference is that I got to sit each day in a nicer waiting room with leather armchairs and newspapers, and a nurse brought me my pre-treatment water to drink in a cut-glass jug with a frilly doily, whereas the NHS waiting room had plastic chairs and a water machine. I then went through a different entrance to the same treatment machines used for NHS patients. The actual treatment was identical.
My insurers approved Space-Oar treatment (I asked them) but I couldn't actually find anywhere to have it done. A hospital which used to do it no longer did. I didn't want to delay my treatment in a more extensive search for it.
All the best,
Chris