The design of clinical trials comparing pi-meson therapy with conventional radiotherapy.

Comparative clinical trials of pi-meson therapy for several tumor sites will be performed in Vancouver using the TRIUMF facility. The design of these trials poses some particular problems related to the limited numbers of patients available. In this paper, some principles of study design are set forth and applied to the issue of randomised and non-randomised designs in general, and to the pi-meson trials in particular.