Introduction to the use of negative pi-mesons in radiation therapy: Rutherford 1964, revisited

The existence of negative pi-mesons was predicted from considerations of infra-nuclear binding forces by Yukawa in 1935. Direct evidence for these unique particles was discovered during cosmic ray research by Lattes, Occhialini and Powell in 1947. I understand that the possibility that pions might be useful in radiation therapy was discussed by Drs. Chaim Richman and Cornelius Tobias here in Berkeley in about 1952. The fist detailed easy on this possibility, by P. H. Fowler and D. H. Perkins, appeared is Nature in 1961 and predicted many of the pertinent characteristics of the potential therapeutic usefulness of negative pi-mesons. Fowler described these in further detail in the 1964 Rutherford Memorial Lecture, entitled "Pi Mesons Versus Cancer." These articles stimulated a search for appropriate methods for production of pi-mesons in sufficient quantity for consideration of human therapy. Unfortunately, as the requirements for such a device are severe, it was not until recently that particle accelerators with sufficiently high beam currents became available. Thus, clinically useful pion channels have been added to proton accelerators at Los Alamos and Vancouver. In addition, a high-yield pion concentrator has been constructed at Stanford for use with a high-intensity electron beam, and this is being adapted in Zurich for use with a proton beam. Preliminary treatment planning, using the known characteristics of pion beams, has yielded interesting and apparently unique treatment plans which promise higher biological dose to the target volume and greater protection to normal tissues. This combination may offer greater opportunity for control of neoplasms at the primary site and also control of such neoplasms as carcinoma of the pancreas and osteosarcoma, known poor responders to conventional high-energy X-irradiation.