There is a difference between Radiation Therapy and RadioSurgery which from what you posted seems like the current cyberknife treatment which is very promising for all types of tumor resection.
You are intuitive and somewhat correct in noticing the difference between stereotactic radiation which sometimes involves more complicated patient immobilization and conventional conformal/imrt fractionated radiation. The cyberknife is an excellent tool for stereotactic radiation, but conventional linear accelerators which are the workhorse of radiation therapy can perform many stereotactic procedures. In the case of renal cell carcinoma, IMRT is suitable with daily IGRT (Image Guided Radiation Therapy) in which a volumetric CT scan is obtained with the linear accelerator, and then anatomy is matched to the original data set for targeting. If there is any discrepancy where the "crosshairs" are, the table upon which the patient is lying can be moved in the x,y,z direction to get things targeted properly. The most important variable in my view is the fractionation, or how the daily dose is given. With conventional radiation therapy, the amount given daily is 1.8-2.0 Gy (a unit of radiation dose-used to be called Rad). With hypofractionation, the daily dose may be 2.5-10 Gy, but the total dose is significantly less. I don't want to bore you with the details of radiobiology, but there are a number of different factors that interplay such as oxygen availability, tumor repopulation, DNA repair, etc.
It has been fun being in this discussion, and I am glad you have survived your cancer. Wish all my patients were that fortunate.