Radiation therapy (RT) treatment planning systems (TPS) are commercially available for routine treatment planning for hospitals. However, cutting edge techniques constantly arise that are not immediately available or reflected in these TPSs. To this end, an TPS is required for experimental purposes that ideally can work in unison with the commercal TPSs. Also, low-cost treatment techniques exist - such as Co60 - that hospitals in developing countries can afford, but not necessarily the accompanying expensive TPS software. To encourage community involvement and ensure transparency, an open-source system is preferred, for which the SlicerRT toolkit is a natural host platform. The External Beam Planning (EBP) SlicerRT module has been developed to become this open-source treatment planning system.

The linear accelerator treatment planning machines are extremely complex pieces of machinery with many geometric parameters to set during a treatment planning process. Manual adjustment of these parameters (such as gantry angle) is already possible in the EBP module. However, it is extremely hard to
1. Understand the actual physical consequences of such a parameter change
2. Keep the internal geometry consistent with the standard IEC coordinate system structure
So a transformation logic is needed to correctly simulate the IEC standard, as well as a user interface that represents the parameters and their effects on the different components of a linac. This representation can be a 3D model of a stylistic linear accelator device that helps the user clearly understand geometric state of the linac.

Update: IEC modelling and user interface are in place. The project now is to generalize the treatment machine model handling to support arbitrary machines.