Naslov
Dosimetric verification of compensated beams using radiographic film

Autori
Jurković, Slaven ; Žauhar, Gordana ; Faj, Dario ; Radojčić Smilović, Djeni ; Švabić, Manda ; Kasabašić, Mladen ; Diklić, Ana

Izvornik
Radiology and oncology (1318-2099) 45 (2011), 4; 310-314

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
radiotherapy ; dosimetry ; compensators

Sažetak
External photon beam modulation using compensators in order to achieve a desired dose distribution when brachytherapy treatment is followed by external beam radiation is a well-established technique. A compensator modulates the central part of the beam, and the dose beneath the thickest part of the compensator is delivered mostly by scattered, low energy photons. A two-dimensional detector with a good spatial resolution is needed for the verification of those beams. In this work, the influence of different types of detectors on the measured modulated dose distributions was examined. Dosimetric verification was performed using X-Omat V, Eastman Kodak radiographic films at different depths in a solid water phantom. The film measurements were compared with those made by ionization chambers. Photon beams were also modelled using EGSnrc Monte Carlo algorithm to explain the measured results. Monte Carlo calculated over-response of the film under the thickest part of the compensator was over 15%, which was confirmed by measurements. The magnitude of over-response could be associated with changes in the spectra of photon energy in the beam. The radiographic film can be used for the dosimetry of compensated high energy photon beams, with limitations in volumes where photon spectra are hardly degraded.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Temeljne medicinske znanosti

POVEZANOST RADA