CLINICAL-APPLICATIONS OF PROTON THERAPY - EXPERIENCES AND ONGOING STUDIES

Proton therapy offers potentially considerable advantages in the manag ement of slow-growing, poorly resectable or non-resectable tumors resi stant to x-rays and located close to critical radiosensitive anatomica l structures, such as the brain stem of the spinal cord. Among over 13 000 irradiated patients in the USA, Europe, and Japan, two major clin ical indications have been documented: 1. The conservative management of choroidal melanomas, in which 98% 5-year local control can be expec ted at the price of low toxicity and visual preservation in approximat ely half of them. 2. The curative management of low-grade chondrosarco mas and chordomas of the base of the skull and cervical spine, leading to, in combination with maximal tumor resection, 84%-94% long-term su rvival. Other ongoing studies concern prostate, head and neck car cino mas as well as various intracranial tumors. Radiosurgical programs are being conducted generally with single fractions and under stereotacti c conditions.