Background and purpose: In CT-based adjuvant radiotherapy of the breast, virtual simulation techniques have been developed. This paper demonstrates a simple virtual simulation of a boost field.
Material and methods: 41 fields were planned virtually, 26 as electron beams, 15 as tangential photon beams.
Results: Depending on the user's expertise the geometric accuracy was high; possible sources of error are illustrated. Resulting field sizes tended to be slightly larger compared to conventional simulation when applying the same rules of field definition. Differences in focus-skin distances with consecutive divergence effects as well as partial volume effects were discussed to be causal.
Conclusion: Virtual simulation of a boost field has the potential to elegantly link the simplicity of a conventional simulation with the accurate tumor bed identification provided by a CT data set. It was shown to be feasible and favorable with regard to the patient, the medical staff, and the simulator time. Moreover, it offers a visualization of dose distributions, which was found helpful in some cases.