Learning from those who do it and exchanging ideas with colleagues is a very important way to gain expertise. For many PTCOG Members who do not have the advantage of sabbatical benefits, but would wish to interact on a more detailed level than what can be accomplished at professional meetings, we start a PTCOG Exchange Program. The list attached shall help to enable exchange of professionals in the field of particle therapy with the goal of reaching highest therapy standards worldwide by exchanging our practical knowledge and experience.