Introduction: The authors characterized the response of EBT3 radiochromic films to proton and carbon ion beams. EBT3 films are adopted routinely for dosimetry and for QA at linear accelerators used for conventional radiotherapy, and for QA in hadrontherapy. In contrast to sparsely ionizing radiations, irradiation by ions leads to a strongly inhomogeneous dose deposition. A quenching effect occurs in the film response consisting of an under-response of the EBT3 to ion beams with respect to MV-photon beams, likely due to the ion track structure. The authors investigated the response of EBT3 films to proton and carbon ion beams, and compared it with photon and electron beams' response, for assessment of a dose–response correction procedure. Method and materials: The EBT3 films were calibrated in the dose range of 0.4–20 Gy with proton (63, 150 and 230 MeV) and carbon ion (115 MeV/u and 400 MeV/u) beams as well as to radiotherapy photon (6, 18 MV and 60 Co) and electron (6 and 12 MeV) beams. The measurements were performed at ‘National Center for Oncological Hadrontherapy’ (CNAO Pavia, Italy) for proton and carbon ion beams and at ‘San Raffaele Hospital’ (HSR Milan, Italy) for photon and electron beams. Results: The dose–response curves were fitted to a quadratic-like function with a relative error of less than 3%. The EBT3 response to protons was found to be very similar to the response of photon and electron beams and no saturation occurred. The relative response of carbon ions was less than unity for all dose values and lower for low-energy ions. The carbon ion curves show an under-response, up to 25% for the lower investigated energy, in comparison with photon and electron curves. Conclusions: For proton beams, at all energies, the dose–response curves are statistically not different from photon and electron curves. For carbon ions an under-response was observed which is higher for lower energy (higher LET) beams
Characterization of the energy dependent response of EBT3 radiochromic film to proton and carbon ion beams / Castriconi, Roberta; Russo, Paolo; Mettivier, Giovanni; DI LILLO, Francesca; Sarno, Antonio; Ciocca, Mario; Mirandola, Alberto; Sini, C; Broggi, S.. - In: PHYSICA MEDICA. - ISSN 1120-1797. - 32:(2016), pp. 10-11. [10.1016/j.ejmp.2016.01.038]
Characterization of the energy dependent response of EBT3 radiochromic film to proton and carbon ion beams
RUSSO, PAOLO;METTIVIER, GIOVANNI;DI LILLO, FRANCESCA;SARNO, ANTONIO;
2016
Abstract
Introduction: The authors characterized the response of EBT3 radiochromic films to proton and carbon ion beams. EBT3 films are adopted routinely for dosimetry and for QA at linear accelerators used for conventional radiotherapy, and for QA in hadrontherapy. In contrast to sparsely ionizing radiations, irradiation by ions leads to a strongly inhomogeneous dose deposition. A quenching effect occurs in the film response consisting of an under-response of the EBT3 to ion beams with respect to MV-photon beams, likely due to the ion track structure. The authors investigated the response of EBT3 films to proton and carbon ion beams, and compared it with photon and electron beams' response, for assessment of a dose–response correction procedure. Method and materials: The EBT3 films were calibrated in the dose range of 0.4–20 Gy with proton (63, 150 and 230 MeV) and carbon ion (115 MeV/u and 400 MeV/u) beams as well as to radiotherapy photon (6, 18 MV and 60 Co) and electron (6 and 12 MeV) beams. The measurements were performed at ‘National Center for Oncological Hadrontherapy’ (CNAO Pavia, Italy) for proton and carbon ion beams and at ‘San Raffaele Hospital’ (HSR Milan, Italy) for photon and electron beams. Results: The dose–response curves were fitted to a quadratic-like function with a relative error of less than 3%. The EBT3 response to protons was found to be very similar to the response of photon and electron beams and no saturation occurred. The relative response of carbon ions was less than unity for all dose values and lower for low-energy ions. The carbon ion curves show an under-response, up to 25% for the lower investigated energy, in comparison with photon and electron curves. Conclusions: For proton beams, at all energies, the dose–response curves are statistically not different from photon and electron curves. For carbon ions an under-response was observed which is higher for lower energy (higher LET) beamsI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
