Accelerators for Hadron Therapy

摘要

Table 1 reproduces a recent update of the statistics presented in a recent paper by Scharf and Wieszczycka. It is seen that about half of all the particle accelerators are used in biomedicine, 80% of them as sources of X rays. Electrons and photons (X rays) produce different spatial distributions in matter. In spite of the roughly exponential decrease in the dose with depth, X-ray beams from a linear accelerator are suitable for an efficient treatment of even "deep-seated" tumour targets. To irradiate such targets selectively, radiotherapists use multiple beam entry ports. Conformity with intensity modulated radiotherapy is thus the main recent development in cancer therapy with conventional radiations (Figure 1).