1. A method for thermal monitoring of tissue during a thermal therapy, comprising: identifying, by processing circuitry, an imaging plane bisection axis, wherein the imaging plane bisection axis lies along at least one of a) a longitudinal axis of a thermal therapy instrument for performing thermal therapy in a patient, and b) a vector through a region of interest within a volume in the patient; identifying, by the processing circuitry, at least a first thermal monitoring plane and a second thermal monitoring plane used in monitoring thermal therapy of the volume, wherein each of the first thermal monitoring plane and the second thermal monitoring plane intersects the region of interest, the first thermal monitoring plane intersects the second thermal monitoring plane at the imaging plane bisection axis, and the first thermal monitoring plane is offset from the second thermal monitoring plane by an angle of intersection; and performing, by the processing circuitry, thermal monitoring of the thermal therapy, wherein the thermal monitoring comprises: obtaining, in real time or near real time from a magnetic resonance (MR) imaging apparatus, a current magnetic resonance (MR) image obtained from the first monitoring plane and a current MR image obtained from the second monitoring plane, calculating, based on the current MR image obtained from the first monitoring plane and the current MR image obtained from the second monitoring plane, temperature data of the volume, and analyzing at least one of the temperature data and a thermal dose that is based on a temperature history of the region of interest over a specified time period to identify completion of thermal therapy of a portion of the region of interest.