2014/10/01 by L. Grzanka, Grzanka, Leszek
Agricultural and Biological Sciences · Medicine · Physics and Astronomy · #Advanced Radiotherapy Techniques #Atomic and Molecular Physics #FOS: Physical sciences #Medical Physics (physics.med-ph) #Radiation Effects and Dosimetry #Radiation Therapy and Dosimetry
paper · pdf · doi:10.48550/arxiv.1410.1378
openalex publication_date 2014/10/01 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
Radiation therapy with carbon ions is a novel technique of cancer\nradiotherapy, applicable in particular to treating radioresistant tumours at\ndifficult localisations. Therapy planning, where the medical physicist,\nfollowing the medical prescription, finds the optimum distribution of cancer\ncells to be inactivated by their irradiation over the tumour volume, is a basic\nprocedure of cancer radiotherapy. The main difficulty encountered in therapy\nplanning for ion radiotherapy is to correctly account for the enhanced\nradiobiological effectiveness of ions in the Spread Out Bragg Peak (SOBP)\nregion over the tumour volume. In this case, unlike in conventional\nradiotherapy with photon beams, achieving a uniform dose distribution over the\ntumour volume does not imply achieving uniform cancer cell inactivation.\n In this thesis, an algorithm of the basic element (kernel) of a treatment\nplanning system (TPS) for carbon ion therapy is developed. The algorithm\nconsists of a radiobiological part which suitably corrects for the enhanced\nbiological effect of ion irradiation of cancer cells, and of a physical beam\ntransport model. In the radiobiological component, Katz's track structure model\nof cellular survival is applied, after validating its physical assumptions and\nimproving some aspects of this model. The Katz model offers fast and accurate\npredictions of cell survival in mixed fields of the primary carbon ions and of\ntheir secondary fragments. The physical beam model was based on available\ntabularized data, prepared earlier by Monte Carlo simulations. Both components\nof the developed TPS kernel are combined within an optimization tool, allowing\nthe entrance energy-fluence spectra of the carbon ion beam to be selected in\norder to achieve a pre-assumed uniform (flat) depth-survival profile over the\nSOBP region, assuring uniform cancer cell inactivation over the tumour depth.\n