(32)P measurements of urine samples and internal dose assessments were conducted for workers in life science laboratories. A procedure for sample pre-treatment was established and validation was performed to exclude interference and to detect (32)P levels accurately. The detection conditions for Cherenkov radiation were evaluated and the accuracy of Cherenkov radiation measurements validated. The analytical and measurement procedures were applied to urine samples collected from 11 workers from life sciences laboratories. The results of the measurements generally indicated very low background radiation levels, but daily urine samples from two workers were above the minimum detectable activity. The (32)P concentrations for two of the workers were 29.3  ±  10.4 Bq•d(-1) and 24.1  ±  11.8 Bq•d(-1), respectively, at intake levels of 4.12 kBq and 2.61 kBq. The effective doses for these two workers were 4.6 μSv and 2.9 μSv. Overall, the results indicate very low levels of radioactivity, except for cases related to specific working conditions.

Purpose: We developed Graphic User Interface (GUI) to evaluate and verify whether Dose Volume Histogram (DVH) parameters meet clinical protocol criteria. Methods: A graphical application to import and evaluate DVH parameters was developed by using Matlab (version R2012a, Mathworks). Two DVH text files which were exported from Eclipse treatment planning system (Varian, USA) could be imported, and it automatically depicts DVH values and arranges dose statistics in Eclipse manner (Figure 1). Additionally, it is possible to evaluate not only KIRAMS dose constraint protocol but also currently well‐known normal tissue constraint protocol such as American Association of Physicists in Medicine (AAPM), Radiation Therapy Oncology Group (RTOG) and Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC). Those protocols were able to be simultaneously depicted on the DVH so that dose constraints were easily distinguishable. Results: DVH data analyzed for all organ parameters with the application was faster than manually looking for points using the treatment planning system. Also, since a protocol‐specific marker used for evaluating dose constraint, the software was easily able to verify each depicted DVH for different types of patient plans whether under the protocol suggested dose or not (Figure 2). Conclusion: This software can help the planner to easily decide how much computer‐calculated DVH was over/under estimated on the basis of the dose constraints that clinical protocols suggested. Acknowledgement : This research was supported by the Ministry of education, Science and Technology(MEST)

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:This study evaluated usability of Multileaf collimator (MLC) for diagnostic radiation in cephalometric exposure using optical stimulated luminance dosimeters (OSLDs)Methods:The MLC material was made alloy tool steel (SKD‐11) and the density of it is 7.89g/m3 that is similar to it of steel (Fe, 7.85 g/m3) and the MLC was attached to general radiography unit (Rex‐650R, Listem Inc, Korea) for cephalometric exposure. The OSLDs that used were nanoDotTM Dosimeter (Landauer Inc, Glenwood, USA) and we read out OSLDs with micro star system (Landauer Inc, Glenwood, USA). The Optical annealing system contained fluorescent lamps (Osram lumilux, 24 W, 280 ∼780 nm). To measure absorbed dose using OSLDs, was carried out dosimetric characteristics of OSLDs. Based on these, we evaluated dose reduction of critical organ (Eyes, Thyroids) with MLC in cephalometric exposureResults:The dosimetric characteristics were following that batch homogeneity was 1.21% and reproducibility was 0.96% of the coefficient of variation The linearity was that the correlation of between dose and count was fitted by linear function (dose,mGy = 0.00029 × Count, R2 =0.997). The range of angular dependence was from −3.6% to 3.7% variation when each degree was normalized by zero degree. The organ dose of Rt. eye, Lt eye, thyroids were 77.8 μGy, 337.0 μGy, 323.1μGy, respectively in open field and the dose reduction of organ dose was 10.6%(8.3μGy), 12.4 %(42 μGy), 87.1%(281.4μGy) with MLCConclusion:We certified dose reduction of organ dose in cephalometric exposure. The dose reduction of Eye was 11% because of reduction of field size and it of thyroids was 87% by primary beam shielding