To spare normal tissues ( such as skin or organs which radiation must pass through to treat the tumor ) , shaped radiation beams are aimed from several angles of exposure to intersect at the tumor , providing a much larger absorbed dose there than in the surrounding , healthy tissue .
To spare normal tissues ( such as skin or organs which radiation must pass through in order to treat the tumor ) , doctors aim weaker radiation beams from several angles of exposure to intersect at the tumor , providing a much larger absorbed dose there than in the surrounding , healthy tissue .