Radiobiology's Contribution to Radiotherapy: Promise or Mirage? Failla Memorial Lecture

KAPLAN, HENRY S. Radiobiology's Contribution to Radiotherapy: Promise or Mirage? Failla Memorial Lecture. Radiat. Res. 43, 460-476 (1970). Each year the Radiation Research Society honors the memory of its principal founder, Gino Failla. I count myself deeply privileged to have known him and to join the group of distinguished scientists who have been invited, through the medium of this lecture, to pay tribute to his many achievements. Failla was trained as a physicist and devoted many years of his life to the solution of physical problems of clinical radiotherapy. Yet this remarkable man had the wisdom to foresee many years ago the need for a society that could weld together the many diverse disciplines that contribute to radiation research. He was also one of the very first radiologic physicists to become aware of the potential significance of radiobiologic research for clinical radiotherapy, a subject which therefore seems altogether fitting for this lecture in his memory. The historical development of radiation therapy has, of necessity, been extensively based on empiricism. As Fowler (1) aptly put it: If therapists had waited for a fully scientific basis before treating the first patient, radiotherapy would not have started yet. But it is sometimes forgotten that, in the first three decades of this century, long before the emergence of radiologic physics as a discipline, radiobiologists worked closely with radiotherapists in attempting to describe and understand the many fascinating new phenomena produced in biological systems by ionizing radiations. As early as 1906, Bergonie and Tribondeau (2) enunciated their famous laws of cellular radiosensitivity; and by 1909, Schwarz (3) had demonstrated that compression of the skin to diminish capillary blood flow reduced the severity of cutaneous radiation reactions, a phenomenon which we now recognize as perhaps the first demonstration of the oxygen effect. Regaud and his colleagues (4, 5) demonstrated that, whereas single doses of radiation directed at the testis always