Patient's cranial position monitoring and controlling device for controlling an MR-guided radiation source module via an MR-guided radiation controlling device to be connected to the patient's cranial position monitoring and controlling device, the patient's cranial position monitoring and controlling device comprises: an MR-guided radiation controlling module, a patient's cranial position monitoring module, and an interface module (150, 155, 160); wherein the patient's cranial position monitoring module is communicatively connected to the MR-guided radiation controlling module; wherein the interface module (150, 155, 160) has an inward side (151, 156, 161) and an outward side (152, 157, 162), wherein the inward side (151, 156, 161) is communicatively connected to the MR-guided radiation controlling module and the outward side (152, 157, 162) is connectable to the MR-guided radiation controlling device; wherein the patient's cranial position monitoring module is adapted for receiving a signal indication for a patient's cranial position during MR-guided radiation treatment by the MR-guided radiation source module; wherein the interface module (150, 155, 160) is adapted for separating an inward communication of the patient's cranial position monitoring and controlling device from an outward communication of the patient's cranial position monitoring and controlling device with respect to MR-imaging relevant noise produced within the patient's cranial position monitoring and controlling device; wherein the MR-guided radiation controlling module is adapted for controlling the MR-guided radiation source module via the MR-guided radiation controlling device to be connected to the outward side (152, 157, 162) of the interface module (150, 155, 160) based on an output of the patient's cranial position monitoring module. an MR-guided radiation controlling module, a patient's cranial position monitoring module, and an interface module (150, 155, 160); wherein the patient's cranial position monitoring module is communicatively connected to the MR-guided radiation controlling module; wherein the interface module (150, 155, 160) has an inward side (151, 156, 161) and an outward side (152, 157, 162), wherein the inward side (151, 156, 161) is communicatively connected to the MR-guided radiation controlling module and the outward side (152, 157, 162) is connectable to the MR-guided radiation controlling device; wherein the patient's cranial position monitoring module is adapted for receiving a signal indication for a patient's cranial position during MR-guided radiation treatment by the MR-guided radiation source module; wherein the interface module (150, 155, 160) is adapted for separating an inward communication of the patient's cranial position monitoring and controlling device from an outward communication of the patient's cranial position monitoring and controlling device with respect to MR-imaging relevant noise produced within the patient's cranial position monitoring and controlling device; wherein the MR-guided radiation controlling module is adapted for controlling the MR-guided radiation source module via the MR-guided radiation controlling device to be connected to the outward side (152, 157, 162) of the interface module (150, 155, 160) based on an output of the patient's cranial position monitoring module.