A system for treating a diseased region of a blood vessel to a desired tissue treatment temperature range, the diseased region of the blood vessel having occlusive material between a vessel lumen and a vessel wall, the system comprising:a balloon for positioning within the vessel adjacent the occlusive materiala cooling fluid supply systema catheter body having a cooling fluid supply lumen, the cooling fluid supply lumen disposed along a cooling fluid path extending distally from the cooling fluid supply system to an interior of the balloon and proximally from the balloon along an exhaust lumen anda controller coupled to the cryogenic fluid supply system and adapted to control cryogenic cooling by modulating a cooling fluid supply rate and/or a cooling exhaust gas port pressure and/or by cycling of the cooling fluid flow in response to a measured thickness of the occlusive material so as to cool the balloon to have an outer surface temperature below the desired tissue temperature range, the outer surface temperature selected to compensate for the measured thickness of the occlusive material.
