yes, we perform CT for breast patients to be treated in DIBH with AlignRT and we do not have GateCT but we are using RGSC (RPM) for monitoring the patient. We take two CT scans, one in free breathing with a low dose protocol for patient positioning and a scan in DIBH. We are using RGSC first for “training” the patient and then to check the stability of the breathing level during the scan. This it all you need and it works just fine.
Hope this helps, Daniel