Michael Tallhamer, MSC, DABR
We would have to know what your planning system is before we could give you specific instructions but it is possible. We use Eclipse at my institution and as in anything within RO there are multiple ways to skin that cat.
If you scan the patient FB then immediately in BH during CT sim you have a couple options. The best one is in the TPS the two scans are co-registered based on sharing the same DICOM coordinates so all you have to do is contour and copy the FB body structure into the BH plan. We name the Free Breathing Body “FB BODY” and the Breath Hold body “BH BODY” so the therapists importing can easily identify the structures when importing into the correct setup fields in AlignRT. This process is easy in Eclipse and allows the dosimetrist to only have to export 1 plan to AlignRT.
A second option is to copy the whole plan to the FB CT scan recontour the body structure to represent the FB body and push both the FB plan and the BH plan but this can cause confusion at the machine when importing if the therapists aren’t careful.
If you have another TPS like Pinnacle or RayStation there may be a similar process but I don’t know what that would be right off the top of my head at the moment. If there isn’t a similar process and you have something like MIM or Velocity the process described above for Eclipse is very easy and very similar in both of those systems but does require and extra step of pushing it back to the TPS.