Αδρονική Θεραπεία: Επιδημιολογική Μελέτη για τον Kαρκίνο στην Ελλάδα και Σχεδιασμός Ιατρικού Επιταχυντή για Αδρονική Θεραπεία

Abstract

Over the past decades, the constantly increasing mortality rates due to cancer are apposing cancer one of the leading causes of death worldwide. Despite the fact that over the years, there has been a significant improve- ment concerning the treatments applied, cancer continues to constitute an important, complex and unsolved medical issue. Tumor irradiation with protons or ions (Hadron Therapy) constitutes one of the most promising treatments available, using cyclotrons or synchrotrons to accelerate the particles. The present thesis, carried out at CERN, consists of two parts: Part I, includes an epidemiologic study in the framework of descriptive epidemiology, concerning cancer in Greece and an analysis of cancer treat- ment with a focus on Hadron Therapy. Statistical data is acquired from cancer registries and information concerning the situation in Greece is obtained from meetings with oncologists and physicians from Greek hos- pitals specializing in cancer. Incidence and mortality rates for each type of cancer based on age and sex, as well as predictions for the next years are presented. Next, the basic types of treatment - chemotherapy, surgery and radiation therapy - are demonstrated along with the side-effects caused by each one. The physics of conventional radiation therapy is introduced, and more importantly, the physical and biological basis of Hadron Ther- apy is analyzed. Moreover, the benefits of Hadron therapy as well as the cases where it is preferably used are presented. Finally, the necessity for Hadron Therapy in Greece is discussed. Part II, focuses on the design of a proton accelerator intended for cancer treatment. The objective is to design a very compact medical synchrotron with a 50 m circumference, smaller than most of the medical synchrotrons under construction or operating in Europe. To begin with, the acceler- ator optics, the particle motion and the beam circulation in a circular accelerator are examined while the concepts of phase advance, tune and emittance are introduced. Necessary parameters such as the strength, size and number of the different type of magnets used in the accelerator ring are defined. Moreover, the magnetic rigidity (Bρ) is calculated, based on the values mentioned above. Next, methods to eliminate the dispersion at the exit of the ring are demonstrated. In addition to this, the tunability of the lattice is examined while a summary of the lattice characteristics is presented. Finally, the stability of the lattice is studied, taking into account the strength of the magnets and the phase advance while a sum- mary of the lattice characteristics is presented. The above study is based on linear beam optics, while the non-linear analysis exceeds the scope of this thesis. This thesis has been performed in the context of a dissertation for a bach- elor degree and as it may be easily understood, the time restrictions could not allow the nessecary investigations which might conclude in more re- alistic results. The reader should bear in mind that the current study aims at providing only the first steps of this very complex field of studies and of course a more thorough investigation is needed. Also, as it is well known worldwide, prestigious medical companies that design medical ac- celerators are working professionally on providing new and more practical technological solutions for a hadron therapy facility.