Preliminary clinical results from U.S. fast neutron teletherapy studies.

Over 700 patients with cancer have been treated with fast neutron beams since 1972 in three U.S. programs at the M.D. Anderson-TAMVEC (Houston and College Station, Texas), University of Washington (Seattle, Washington), and MANTA (Naval Research Laboratory, Washington, D.C.). Clinical applications are about to start at the Fermilab (Batavia, Illinois) and Cleveland Clinic-NASA (Cleveland, Ohio). To date, studies have included: 1) effects of different treatment patterns and doses; 2) responses of several tumor types at many anatomic sites; and 3) acute and long-term normal tissue tolerances. Responses of several cancers, such as extensive epidermoid carcinoma of the cervix and "fixed" metastatic cervical adenopathy, have been encouraging. In patients with glioblastoma multiforme, good tumor responses have not lengthened survival compared with the following conventional radiation therapy. Both local tumor control and "cure" have been compromised by the inclusion of patients with very extensive cancers. In general, treatment has been well tolerated. These preliminary studies provide the basis for planned clinical trials.