An appraisal of particle radiation therapy research

Abstract

Biomedical particle radiation research was made possible by the development of the cyclotron by Lawrence and Livingstone2’ nearly simultaneously with the identification of the neutron by Chadwick’ in 1932. Studies of the biological effects of neutrons began immediately and by 1938 a clinical trial of the treatment of humans with cancer began in Berkeley, California, under the direction of Robert Stone. 3o This trial was doomed to fail for, as later noted by Sheline et af.,” unacceptable late-damage to normal tissues resulted from inadvertant overdosage because of: a lack of understanding that the relative biologic effects of neutrons compared to x and gamma rays increase with decreasing dose increment size: primitive dosimetry; unawareness of the contributions of exitdoses; and failure to comprehend the importance of residual damage from previous radiation treatment. Thus, in the Janeway Lecture of 1947, Stone29 concluded that “neutron therapy, as administered by us, has resulted in such bad late sequelae in proportion to the few good results that it should not be continued” and so deterred further clinical application for over 20 years. The re-birth of biomedical particle radiation research was based on radiobiology and physics studies made possible by Medical Research Council sponsorship of a dedicated cyclotron installed in the Hammersmith Hospital, London, in 1955.”