Analysis of dosimetric characteristicts of high-energy therapeutic beams in radiotherapy

Ionizacijsko zračenje ima vrlo važnu upotrebu u dijagnostici i tretmanu malignih bolesti u radioterapiji. Doza zračenja isporučena pacijentu mora bit precizna i s visokom numeričkom točnošću. Da bismo bili sigurni da propisana i isporučena doza zračenja imaju minimalnu razliku rade se testovi sigurnosti i ispravnosti linearnog akceleratora korištenjem fantomskog sustava. U ovom radu riječ je o analizi dozimetrijskih karakteristika fotonskih i elektronskih snopova generiranih modernim linearnim akceleratorom Elekta. Mjerenja su izvršena u suradnji s Odjelom medicinske fizike na Klinici za onkologiju i radioterapiju, KBC-a Split. Uz pomoć vodenog fantomskog sustava, snimljeni su i analizirani fotonski snopovi energija 6 MV i 18 MV za polje veličine 10 cm x 10 cm, te elektronski snopovi energija 6 MeV, 10 MeV, 12 MeV i 16 MeV za polje veličine 20 cm x 20 cm. Dobiveni rezultati odstupanja u skladu su s odstupanjima koji su propisani Pravilnikom od strane Sektora za radiološku i nuklearnu sigurnost Ravnateljstva civilne zaštite Republike Hrvatske.Ionizing radiation has a very important utilization in diagnostics and treatment of malignant diseases in radiotherapy. The radiation dosage given to the patient has to be precise and with high numerical accuracy. In order to be certain that prescribed and delivered radiation dosage have a minimal difference, some tests are done. Those tests are tests of safety and correctness of linear accelerator by using phantom system. The topic of this research paper is the analysis of dosimetric characteristics of photonic and electronic beams, which are generated with modern linear accelerator Elekta. Measurements are done in a collaboration with the Department of medical physics at Oncology and Radiotherapy Clinic, KBC Split. With the help of water phantom system, some analysed photonic beams are recorded with the energy of 6 MV and 18 MV for the 10 cm x 10 cm sized field, and electronic beams of 6 MeV, 10 MeV, 12 MeV and 16 MeV for the 20 cm x 20 cm sized field. Obtained deviation results are in accordance with deviations which are regulated by the Regulation set by the Sector for radiological and nuclear safety of Civil protection department of Republic Croatia