Radiation therapy is usually using linear accelerator and used X-ray energy is also getting higher. Recently linear accelerators has been developed 3F mode and tracking jaw technology and that was applied for patient therapy. This study aims at measuring photoneutrons depending on the use of 3F and tracking jaw system when radiation is irradiated using a linear accelerator. The generation of photoneutrons of 3F system was 70% smaller than 2F system and that of tracking jaw system was 83% higher than static jaw system. Photoneutron value is relatively low. However, it must be minimized for Photoneutron exposure during radiation therapy.

In this study, we analyzed the effects of radiation exposure, as compared to the hematological parameters change of medical radiation workers and the public. The mean value of all hematological parameters were in the normal range. Eosin mean value of the radiation workers(2.52 ± 1.79%) showed that a significantly lower than the control group(2.92 ± 1.39%). In the comparison of the results depending on the occupation period, it showed high value that the mean of the radiation workers group WBC, platelet, Lymph, Mono, Baso. Over 20 years of radiation workers WBC, Mono showed low values and less than 10 years of radiation workers mean value of Baso showed low values, there was no statistical significance. In the comparison of the results depending on the 4 years cumulative radiation dose, Over 5.0 m㏜ of Radiation works RBC(4.61 ± 0.53 vs 4.91 ± 0.38), Hct(41.51 ± 4.07 vs 43.97 ± 3.40), Eosin(1.74 ± 1.14 vs 2.92 ± 1.39) showed low value, it was statistical significance. 0.5∼1.0 m㏜ radiation exposure workers Hb (13.93 ± 1.75) showed a significantly lower value than that of the control group (14.90 ± 1.29).