A system and method for fluid control in a thermal therapy system is disclosed. A fluid circuit permits passage of a fluid through a fluid circuit, including into and out of a treatment zone so as to cool or heat or maintain a temperature in said treatment zone at or near a desired temperature. The temperature is sensed at a point in the circuit between a discharge of a fluid pump and the treatment zone. MRI based thermometry of tissue in the treatment zone is accomplished in some aspects. Furthermore, a desired temperature may be programmably set to a given value or within a band of values using a processor and a temperature controller. In some aspects, leakage of fluid from a patient or from the fluid control system is captured by a leak-proof member to protect imaging and treatment equipment from damage.