Review and evolution of clinical results in the EORTC Heavy-Particle Therapy Group.

Part of the clinical results from the "EORTC Heavy-Particle Therapy Group" are reviewed (September 1984). Fast neutrons can bring a significant benefit, compared to conventional photon (or electron) techniques, in well defined patient series. A benefit for neutrons is observed, in Hammersmith and in Amsterdam, for locally extended salivary gland tumours. Soft tissue sarcomas can also be considered as a good indication for neutron therapy, especially when they are slowly growing and well differentiated, as shown in Essen, Hammersmith and Louvain-la-Neuve. Neutrons can bring an advantage in the treatment of some melanoma patients as shown in Hammersmith. For locally advanced prostatic carcinoma, better results for neutrons are shown in Hamburg and Louvain-la-Neuve. These data are similar to those observed in the United States from the RTOG studies. Due to a reduced differential effect between tissues after neutron treatment, irradiation of large volumes of normal tissues, at high neutron dose, should be avoided. Different possible combinations between neutrons and photons (boost, mixed schedule) are discussed.