Is imrt more precise n less harmful to the skin than crt and thus the cost difference ?

IMRT: Imrt is a more precise method of radiation therapy that is more precisely directed to the organ or area being treated and that way less harmful to surrounding tissues including skin.

More Focused: Imrt (intensity modulated radiotherapy) can often focus treatment more precisely than 3dcrt (3d conformal radiation). It is more expensive due more costly machines and the extra work the radiation oncologist and her/his team (dosimetrist, physicist, etc.) put in to prepare and deliver the treatment. In many, but not all cases, imrt may decrease the side effects of therapy including skin effects.

The target dose may: Be more precise. The total body dose (aka integral dose) is actually higher, albeit quite low doses. But these very low doses may be quite dangerous. Physician, physics, safety time to verify modulating leaflets are costly. Imrt has been used excessively, and needs to be used only for clear patient benefit.