Contributions to new challenges in radiotherapy. From small field dosimetry to stereotactic body radiation therapy

• Autores: Josep Puxeu Vaqué
• Directores de la Tesis: Mercè Ginjaume Egido (dir. tes.), M. Amor Duch Guillen (codir. tes.)
• Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2015
• Idioma: español
• Tribunal Calificador de la Tesis: W. Philip Mayles (presid.), Josep Sempau Roma (secret.), Alberto Sánchez-Reyes Fernández (voc.)
• Materias:
  • Ciencias de la vida
    • Biofísica
      • Física médica
  • Ciencias médicas
    • Ciencias clínicas
      • Sifilografía
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • The use of small Fields has substantially increased in radiotherapy during recent years mainly due to expansion in the use of modulated techniques which are also used at some institutions for Stereotactic Body Radiotherapy (SBRT). The use of modulated techniques in lung SBRT is controversial due to the interplay effect. At the same time, small-volume dosemeters have appeared on the market in an attempt to try to cover new dosimetry necessities.

    This PhD deals with different features related to small-field dosimetry. It first analyzes the influence of differences between ionization chambers of the same type on dosimetry factors determining 0.5% as the upper limit on the possible influence. Correction factors for PTW-31016 are also proposed and the effect of a particular chamber of this model has been found to be up to 2.8% for 0.5 cm square. These correction factors have been determined by Monte Carlo calculations and have been validated with measurements on fattened and unflattened beams by analyzing the main sources of influence. The last chapter is devoted to SBRT, and suggests a fast and accurate plan set-up together with PUMA, a method to evaluate the interplay effect in lung SBRT.