To be honest I wouldn't be worried about lessening radiation. radiation totally sucks - it's not easy - even for the best case scenario with rads it is bad (not gonna lie) however, I'm a do what you can person - I would rather dig in and deal with it all now (hit it with everything you've got right out of the gate) rather than try and take it easy with the treatment and face a potential (highly likely - and possibly fatal) recurrence 1-2 years down the road.
The treatment is scary as crap - but I've seen it happen far too many times that the patient is ambivalent about the full course of treatment - drs. sense this btw - so the drs back off and don't follow through with what they really think should be done, and literally within a year or two they are chasing the cancer again.

To me if a surgery is recommended - that removes what should be the bulk or all of the cancer -it's worth it. That leaves the rads to do its job - as a clean up man. the surgery of the two treatments is the most recoverable try not to worry. Hugs.