• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.409-414
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• 2013

In this study, we evaluated to the superiority of treatment techniques on prostate cancer, apply to each other treatment techniques-3D conformal therapy versus IMRT-using dose distribution and dose coverages. Obtained 10 patients CT simulation, divided tumor volume and critical organs. Prescription dose was 80 Gy on tumor volume and Each of plans was set by two different plans. As a result, Dose coverage was superior to IMRT. The IMRT's tumor absorbed dose(100.2%) was close to prescription doses. Normal tissue(bladder, rectal, bowel Lt Rt fumoral head) absorbed dose rate was superior. In other words, the radiation therapy of prostate cancer with intensity modulated radiation therapy was better than conformal radiation therapy on dose.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.471-476
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• 2022

The purpose of this study was to study the probability of cancer occurrence due to photoneutron dose exposure of the colon and thyroid gland, which are normal organs, in 3D CRT, IMRT 5 portals, and IMRT 9 portals, which are radiotherapy methods for prostate cancer. The total prescribed dose for prostate cancer was 6600 cGy, 220 cGy per dose, and 30 divided irradiations were applied for the total number of times. After setting up the Rando phantom on the treatment table (couch) of the medical linear accelerator used in the experiment, an optically stimulated luminescence albedo neutron dosimeter was placed on the corresponding area of the large intestine and thyroid gland of the phantom for measurement. During 3D CRT of prostate cancer, the probability of secondary cancer due to photoneutron dose to the colon and thyroid gland, which are normal organs, was 1.8 per 10,000 people. And IMRT 5 portals were 8.7 per 10,000 people, which was about 5 times larger than 3D CRT. IMRT 9 portals derived the result that there is a probability that 1.2 people per 1,000 people will develop cancer. Based on this study, the risk of secondary radiation exposure due to the dose of photoneutrons generated during radiation therapy is studied, and it is thought that it will be used as useful data for radiation protection in relation to the stochastic effect of radiation in the future.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.473-479
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• 2023

In this study, the dose of photoneutrons generated during radiotherapy of prostate cancer using high energy was measured using a photo-stimulated luminescence dosimeter. In addition, this study was intended to study the probability of side effects occurring in the abdomen. A medical linear accelerator capable of generating 15 MV energy, True Beam STx (Varian Medical Systems, USA) and a radiation treatment planning system (Eclipse, Varian Medical Systems, USA) were used. A human body phantom was installed on the couch of the linear accelerator, and an Albedo Neutron Optical Stimulation Luminescence Neutron Detector (Landauer Inc., IL, USA) was used to measure the photoneutron dose. The photoneutron dose value in the abdomen of VMAT and 3C-CRT was 52.8 mSv, more than twice as high as VMAT compared to 3D-CRT. During radiotherapy of prostate cancer, the probability of causing side effects in the abdomen due to light neutron dose was calculated to be 3.2 per 1,000 for VMAT and 1.4 for 3D-CRT. By studying the abdomen, which has a major side effect that can occur during radiotherapy of prostate cancer, it is expected that it will be used as a meaningful study to study the quality of life and stochastic effect of prostate cancer patients

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.481-487
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• 2023

In this study, we analyzed the incidence of side effects of photoneutron dose according to the number of beams during intensity-modulated radiotherapy of prostate cancer using 15 MV. The radiation treatment plan design for intensity-modulated radiation therapy for prostate cancer was established with a prescription dose of 220 cGy per dose and a total of 7260 cGy for 33 treatments. The linear accelerator used in the experiment is Varian's True Beam STx (Varian, USA). Photoneutron dose was generated by using 15 MV energy in the planning target volume (PTV). The treatment plan was designed with IMRT 5, 7, and 9 portals using the Eclipse System (Varian Ver 10.0, USA). An optically stimulated luminescence albedo neutron dosimeter (Landauer Inc., USA) was used to measure photoneutron dose. IMRT 5 portals, 1.7 per 1,000, 7 portals, 1.8 per 1,000, 9 portals, 2.0 per 1,000 were calculated as the probability of experiencing side effects on the thyroid gland due to photoneutron dose. This study studies the risk of secondary radiation exposure dose that can occur during intensity-modulated radiation therapy, and it is considered that it will be used as useful data in relation to stochastic effects in the future.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.53-60
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• 2015

Purpose : The purpose of this study is to evaluate the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. Materials and Methods : The phantom is produced to equally describe prostate and rectum based on a 3D volume contour of an actual prostate cancer patient who is treated in Asan Medical Center by using a 3D printer (3D EDISON+, Lokit, Korea). CT(Computed tomography) images of phantom are aquired by computed tomography (Lightspeed CT, GE, USA). By using treatment planning system (Eclipse version 10.0, Varian, USA), treatment planning is established after volume of a prostate cancer patient is compared with volume of the phantom. MOSFET(Metal OXIDE Silicon Field Effect Transistor) is estimated to identify precision and is located in 4 measuring points (bladder, prostate, rectal anterior wall and rectal posterior wall) to analyzed treatment planning and measured value. Results : Prostate volume and rectum volume of prostate cancer patient represent 30.61 cc and 51.19 cc respectively. In case of a phantom, prostate volume and rectum volume represent 31.12 cc and 53.52 cc respectively. A variation of volume between a prostate cancer patient and a phantom is less than 3%. Precision of MOSFET represents less than 3%. It indicates linearity and correlation coefficient indicates from 0.99 ~ 1.00 depending on dose variation. Each accuracy of bladder, prostate, rectal anterior wall and rectal posterior wall represent 1.4%, 2.6%, 3.7% and 1.5% respectively. In- vivo dosimetry represents entirely less than 5% considering precision of MOSFET. Conclusion : By using a 3D printer, possibility of phantom production based on prostate is verified precision within 3%. effectiveness of In-vivo dosimetry is confirmed from a phantom which is produced by a 3D printer. In-vivo dosimetry is evaluated entirely less than 5% considering precision of MOSFET. Therefore, This study is confirmed the usefulness of a 3D printed phantom for in-vivo dosimetry of a prostate cancer patient. It is necessary to additional phantom production by a 3D printer and In-vivo dosimetry for other organs of patient.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.218-227
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• 2009

Purpose: To investigate the radiobiologic effects of neutron and X-ray irradiation on DU-145 prostate carcinoma cells by identifying the differences of HIF-$1\alpha$ expression and apoptosis. Materials and Methods: Nude mice were injected with the human prostate cancer cell line, DU-145, and then irradiated with 2 Gy and 10 Gy X-rays, or 0.6 Gy and 3.3 Gy neutrons, respectively. The mice were sacrificed at 24 hours and 120 hours after irradiation. The expression levels of HIF-$1\alpha$, Bcl-2 and Bax were compared with immunohistochemical staining and western blotting. The apoptotic indexes were compared with the Terminal deoxynucleotidyl biotin-dUTP nick and labeling (TUNEL) assay. Results: At day 1, HIF-$1\alpha$ and Bcl-2 expression decreased, while Bax expression and the number of TUNEL positive cells increased in neutron irradiated groups for the control and X-ray irradiated groups. The Bcl-2/Bax ratio was significantly lower in the neutron irradiated groups regardless of dose (p=0.001). The same pattern of the differences in the expressions of the HIF-$1\alpha$, Bcl-2, Bax, Bcl-2/Bax ratio, and apoptotic indexes were indentified at day 5. HIF-$1\alpha$ expression was related with Bcl-2 (p=0.031), Bax (p=0.037) expressions and the apoptotic indexes (p=0.016) at day 5. Conclusion: Neutron irradiation showed a decrease in HIF-$1\alpha$, Bcl-2 expression, and Bcl-2/Bax ratio, but increased Bax expression regardless of dose. This study suggests that the differences radiobiological responses between photon and neutron irradiation may be related to different HIF-$1\alpha$ expression and subsequent apoptotic protein expressions.

• Journal of agricultural medicine and community health
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• v.39 no.1
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• pp.46-58
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• 2014

Objectives: This study was aimed to analyze the trends of cancer incidence and evaluate the quality control of cancer registration data in Jeollabuk-do from 2001 to 2010. Methods: Incidence data of all cancers and indices of quality of cancer registration data in Jeollabuk-do for the 10-year period were obtained from the Population-based Regional Cancer Registry in the Jeonbuk Regional Cancer Center. Trends in crude incidence rate (CR) and age-standardized incidence rate (ASR) for all cancers and incidence rates for major cancer sites by gender were analyzed. Joinpoint regression tool was used to describe and quantify trends. And the completeness and validity of cancer registration data were analyzed. Results: The major cancer sites in males were the stomach (22.2%), lung (16.6%), colorectum (12.8%), liver (12.3%) and prostate (6.2%), and in females were the thyroid (17.8%), stomach (14.7%), breast (11.6%), colorectum (11.5%) and lung (7.7%). Between 2001 to 2010, ASR for all cancers increased 13.7% in men, 68% in women, and 36.5% overall. ASR for all cancers increased by 1.2% per year in males and by 6.7% per year in females from 2001 to 2010. In the quality control of the cancer registration data between 2001 and 2010, death certificate only (DCO%) for men was decreased from 5.6% to 1.3% and DCO% for women decreased from 6.1% to 1.8%. Microscopic verification (MV%) increased in both men and women. And mortality/incidence ratio (MI%) declined in both men and women. Conclusions: The cancer incidence during the 10 years (2001-2010) in Jeollabuk-do was increasing especially for the colorectum and prostate in men, and for the thyroid and breast in women. The overall quality control of the cancer registry was gradually improving.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.167-174
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• 2015

Purpose : The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Materials and Methods : Test was used for TrueBeam STx$^{TM}$ (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). Results : The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Conclusion : Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.