medical linear accelerators are one of the most widespread methods for cancer treatment. despite their advantages, unwanted photoneutrons are produced by high energy linacs. this photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. photoneutrons radiological risk must be evaluated because of their high let and range.in o...

The role of radiation therapy in cancer management is first defined: today among the cancer patients who are cured (≅ 45 %) about one half are cured by radiation therapy applied alone or in combination with surgery or chemotherapy. The experience accumulated in decades shows that, to be efficient, the radiation treatment must be delivered with a high physical selectivity. At present, electron l...

For the medical linear accelerators (linac) that utilize more than 10 MV of photon energy, components inside linac head become radioactivate during 10–15-year operating cycle. Prior to disposal, radioactive waste must be evaluated for activity, and same procedure should followed linacs. In Republic Korea, regulation methodology radioactivity evaluation is not established yet. this study, we emp...

Medical linear accelerators are one of the most widespread methods for cancer treatment. Despite their advantages, unwanted photoneutrons are produced by high energy linacs. This photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. Photoneutrons radiological risk must be evaluated because of their high LET and range.in o...

Simulation software for medical linear accelerators that can be used in a teaching environment was developed. The components of linear accelerators were modeled to first order accuracy using analytical expressions taken from the literature. The expressions used constants that were empirically set such that realistic response could be expected. These expressions were programmed in a MATLAB envir...

Medical linear accelerators are one of the most widespread methods for cancer treatment. Despite their advantages, unwanted photoneutrons are produced by high energy linacs. This photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. Photoneutrons radiological risk must be evaluated because of their high LET and range.in o...

Activation products have been identified by in situ gamma spectroscopy at the isocenter of a medical linear accelerators shortly after termination of a high energy photon beam irradiation with 15 x 15 cm field size. Spectra have been recorded either with open or with closed collimator. Whilst some activation products disappear from the spectrum with closed collimator or exhibit reduced count ra...

In order to promote consensus building on decommissioning operation rules for medical linear accelerators in Japan, we carried out a risk communication (RC) approach mainly providing knowledge for maintenance staff regarding induced radioactivity. In February 2012, we created a booklet (26 pages) to present an overview of the amended law, the mechanism and the distribution of induced radioactiv...