Purpose: To estimate the three dimensional dose distributions in a polymer gel and a radiochromic gel by comparing with the virtual water phantom exposed to proton beams by applying Monte Carlo simulation. Methods: The polymer gel dosimeter is the compositeness material of gelatin, methacrylic acid, hydroquinone, tetrakis, and distilled water. The radiochromic gel is PRESAGE product. The densities of polymer and radiochromic gel were 1.040 and 1.0005 g/cm3, respectively. The shape of water phantom was a hexahedron with the size of 13 × 13 × 15 cm3. The proton beam energies of 72 and 116 MeV were used in the simulation. Proton beam was directed to the top of the phantom with Z‐axis and the shape of beam was quadrangle with 10 × 10 cm2 dimension. The Percent depth dose and the dose distribution were evaluated for estimating the dose distribution of proton particle in two gel dosimeters, and compared with the virtual water phantom. Results: The Bragg‐peak for proton particles in two gel dosimeters was similar to the virtual water phantom. Bragg‐peak regions of polymer gel, radiochromic gel, and virtual water phantom were represented in the identical region (4.3 cm) for 72 MeV proton beam. For 116 MeV proton beam, the Bragg‐peak regions of polymer gel, radiochromic gel, and virtual water phantom were represented in 9.9, 9.9 and 9.7 cm, respectively. The dose distribution of proton particles in polymer gel, radiochromic gel, and virtual water phantom was approximately identical in the case of 72 and 116 MeV energies. The errors for the simulation were under 10%. Conclusion: This work indicates the evaluation of three dimensional dose distributions by exposing proton particles to polymer and radiochromic gel dosimeter by comparing with the water phantom. The polymer gel and the radiochromic gel dosimeter show similar dose distributions for the proton beams.

This article does not require IRB/IACUC approval because there are no human and animal participants.

It is confirmed that high correlations between the movements of external marker and the targetassigned in diaphragm in the experimental case for the mini pig were existed. Therefore, it is possible to predict the locations of internal target from the movement of the external marker. These results show the possibility to use the DTTRT (Dynamic Tumor Tracking Radiation Therapy) system of Korea Institute of Radiological and Medical Science (KIRAMS) to clinical application of animals.

Purpose: We aimed to evaluate optical stimulated luminance dosimeters (OSLD) to estimate high dose in 60Co unit and to compare to advanced study about OSLDMethods: OSLDs were grouped into three groups by radiation sensitivity (serial No.) and each groups consisted of dosimeters with variation of radiation sensitivity within ± 1.5% among them by sampling. When we evaluated dosimetric characteristics of OSLD, indicated used OSLD groups in list of evaluation of the dosimetric characteristics of them. OSLD had supra‐linear response from more than 3 Gy. So the correlation of between dose delivered from 60Co and count was fitted by quadratic function. We compared to calculation dose and delivery dose in more than 3 GyResults: The reproducibility was 0.76% of the coefficient of variation, the batch homogeneity was within 1.5 % of the coefficient of variation and the depletion by repeat reading was 0.04% per reading. The half time of count decay curve after irradiation according to reading time was 0.68 min. (1 Gy), 1.04 min. (5 Gy), and 1.10 min. (10 Gy), respectively and the count decay was stable after 11 min, After stability, coefficient of variation was within 0.4%.The removal rate of count by optical annealing time (30min.) after OSLD reading was 88% (1 Gy), 90% (5 Gy), and 92% (10 Gy), respectively and was 99% when they were annealed for 4hour. The diff. % of between delivery dose form 60Co unit and calculated dose from fitting model was within ± 4.0%. But the OSLDs irradiated dose above 20 Gy changed their radiation sensitivity. So it is necessary to use carefully them and to calibrate radiation sensitivity of themConclusion: Considering to uncertainty of count for procedure, if delivery dose was calculated, it is feasible to use OSLD for evaluation of high dose in 60Co unit. Acknowledgement:This research was supported by the Ministry of education, Science and Technology(MEST)

Purpose: To estimate the three dimensional dose distributions for proton, proton induced gamma rays and proton induced neutron particles, in case of exposing the proton beam to a polymer gel dosimeter and a water phantom. Methods: The polymer gel dosimeter was compositeness material of gelatin, methacrylic acid, hydroquinone, tetrakis and distilled water. The density of the gel dosimeter was 1.04g/cm3 which density was similar to water. The proton beam energies of 72 and 116 MeV were used in the simulation. Proton beam was directed to the top of a cylindrical phantom which radius was 5 cm and height was 12.2 cm for covering the proton Bragg‐peak (on X‐axis). The proton beam interacted with the nuclei of the phantom and the nuclei in excited states emitted prompt gamma rays and proton induced neutron particles during the process of de‐excitation. The proton particles, gamma prays and induced neutron were detected by the gel dosimeter and water phantom, respectively. The gap of the X‐axis was 2 mm. Results: The Bragg‐peak for proton particles in the gel dosimeter was similar to water phantom. The dose distribution for proton and prompt gamma rays in the gel dosimeter and water phantom was approximately identical in case of 72 and 116 MeV for proton beam. However, in case of proton induced neutron particles for 72 and 116 MeV proton beam, particles were not detected in the gel dosimeter, while the water phantom absorbed neutron. Conclusion: For the evaluation of proton dose distribution, the gel dosimeter was valuable tools for three dimensional measurements. This work indicates the evaluation for dose distribution of proton, induced gamma, and neutron in the gel dosimeter compared with the water phantom. Considering the Result data, the gel dosimeter which was developed in the normoxic state attentively detected the dose distribution for proton beam exposure except neutron particles.