SGRT Forum

With a tattoo workflow, the treatment planning process generally generates 'shifts' indicating the delta from the tattoos to the plan isocentre. Also sometimes called set up offsets. These offsets are exported with the plan to the OIS eg. MOSAIQ. In a tattooless workflow where using SGRT to move directly to the plan iso, these offsets are not used (I believe). Are these values still exported with the plan and if so, why? Thanks

Hi Clare, in our centre we still generate shifts in TPS even although we are tattooless. Our tattooless workflow in CT is exactly the same as the tattoo workflow other than not actually tattooing at the end. We record references where we would normally have put the tattoos and record that in Mosaiq. The TPS then generates shifts from here and we record them in mosaiq also. We never use them but it forms our contingency plan in case an SGRT system went down, we would set the linac lasers to the recorded reference points, perform the offset shifts generated by the TPS, image and then treat. It would be very unusual to have to do this but it formed part of our governance around going tattooless. Thanks

Thanks Amy

Hello Amy
We recently started using an SGRT system but are still very reluctant to remove the tatoos, just in case the
system fails. I wanted to ask you which anatomical references you use to set the origin point that you would use.
Thank you