• Journal of Radiation Protection and Research
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• v.46 no.2
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• pp.39-47
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• 2021

Background: The National Institutes for Quantum and Radiological Science and Technology-National Institute of Radiological Sciences (QST-NIRS) has continuously investigated the undesired radiation exposure in ion beam radiotherapy mainly in carbon-ion radiotherapy (CIRT). This review introduces our investigations on the secondary neutron dose in CIRT with the broad and scanning beam methods. Materials and Methods: The neutron ambient dose equivalents in CIRT are evaluated based on rem meter (WENDI-II) measurements. The out-of-field organ doses assuming prostate cancer and pediatric brain tumor treatments are also evaluated through the Monte Carlo simulation. This evaluation of the out-of-field dose includes contributions from secondary neutrons and secondary charged particles. Results and Discussion: The measurements of the neutron ambient dose equivalents at a 90#x00B0; angle to the beam axis in CIRT with the broad beam method show that the neutron dose per treatment dose in CIRT is lower than that in proton radiotherapy (PRT). For the scanning beam with the energy scanning technique, the neutron dose per treatment dose in CIRT is lower than that in PRT. Moreover, the out-of-field organ doses in CIRT decreased with distance to the target and are less than the lower bound in intensity-modulated radiotherapy (IMRT) shown in AAPM TG-158 (American Association of Physicists in Medicine Task Group). Conclusion: The evaluation of the out-of-field doses is important from the viewpoint of secondary cancer risk after radiotherapy. Secondary neutrons are the major source in CIRT, especially in the distant area from the target volume. However, the dose level in CIRT is similar or lower than that in PRT and IMRT, even if the contributions from all radiation species are included in the evaluation.

• The Journal of Korean Society for Radiation Therapy
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• v.32
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• pp.17-29
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• 2020

Purpose: The purpose of this work was to investigate the dosimetric impact of mixed energy partial arc technique on prostate cancer VMAT. Materials and Methods: This study involved prostate only patients planned with 70Gy in 30 fractions to the planning target volume (PTV). Femoral heads, Bladder and Rectum were considered as oragan at risk (OARs). For this study, mixed energy partial arcs (MEPA) were generated with gantry angle set to 180°~230°, 310°~50° for 6MV arc and 130°~50°, 310°~230° for 15MV arc. Each arc set the avoidance sector which is gantry angle 230°~310°, 50°~130° at first arc and 50°~310° at second arc. After that, two plans were summed and were analyzed the dosimetry parameter of each structure such as Maximum dose, Mean dose, D2%, Homogeneity index (HI) and Conformity Index (CI) for PTV and Maximum dose, Mean dose, V70Gy, V50Gy, V30Gy, and V20Gy for OARs and Monitor Unit (MU) with 6MV 1 ARC, 6MV, 10MV, 15MV 2 ARC plan. Results: In MEPA, the maximum dose, mean dose and D2% were lower than 6MV 1 ARC plan(p<0.0005). However, the average difference of maximum dose was 0.24%, 0.39%, 0.60% (p<0.450, 0.321, 0.139) higher than 6MV, 10MV, 15MV 2 ARC plan, respectively and D2% was 0.42%, 0.49%, 0.59% (p<0.073, 0.087, 0.033) higher than compared plans. The average difference of mean dose was 0.09% lower than 10MV 2 ARC plan, but it is 0.27%, 0.12% (p<0.184, 0.521) higher than 6MV 2 ARC, 15MV 2 ARC plan, respectively. HI was 0.064±0.006 which is the lowest value (p<0.005, 0.357, 0.273, 0.801) among the all plans. For CI, there was no significant differences which were 1.12±0.038 in MEPA, 1.12±0.036, 1.11±0.024, 1.11±0.030, 1.12±0.027 in 6MV 1 ARC, 6MV, 10MV, 15MV 2 ARC, respectively. MEPA produced significantly lower rectum dose. Especially, V70Gy, V50Gy, V30Gy, V20Gy were 3.40, 16.79, 37.86, 48.09 that were lower than other plans. For bladder dose, V30Gy, V20Gy were lower than other plans. However, the mean dose of both femoral head were 9.69±2.93, 9.88±2.5 which were 2.8Gy~3.28Gy higher than other plans. The mean MU of MEPA were 19.53% lower than 6MV 1 ARC, 5.7% lower than 10MV 2 ARC respectively. Conclusion: This study for prostate radiotherapy demonstrated that a choice of MEPA VMAT has the potential to minimize doses to OARs and improve homogeneity to PTV at the expense of a moderate increase in maximum and mean dose to the femoral heads.

• Journal of Preventive Medicine and Public Health
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• v.55 no.5
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• pp.464-474
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• 2022

Objectives: We introduced the cohort studies included in the Korean Cohort Consortium (KCC), focusing on large-scale cohort studies established in Korea with a prolonged follow-up period. Moreover, we also provided projections of the follow-up and estimates of the sample size that would be necessary for big-data analyses based on pooling established cohort studies, including population-based genomic studies. Methods: We mainly focused on the characteristics of individual cohort studies from the KCC. We developed "PROFAN", a Shiny application for projecting the follow-up period to achieve a certain number of cases when pooling established cohort studies. As examples, we projected the follow-up periods for 5000 cases of gastric cancer, 2500 cases of prostate and breast cancer, and 500 cases of non-Hodgkin lymphoma. The sample sizes for sequencing-based analyses based on a 1:1 case-control study were also calculated. Results: The KCC consisted of 8 individual cohort studies, of which 3 were community-based and 5 were health screening-based cohorts. The population-based cohort studies were mainly organized by Korean government agencies and research institutes. The projected follow-up period was at least 10 years to achieve 5000 cases based on a cohort of 0.5 million participants. The mean of the minimum to maximum sample sizes for performing sequencing analyses was 5917-72 102. Conclusions: We propose an approach to establish a large-scale consortium based on the standardization and harmonization of existing cohort studies to obtain adequate statistical power with a sufficient sample size to analyze high-risk groups or rare cancer subtypes.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.151-158
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• 2007

The possibility of inadvertent introduction of therapeutic gene expressing viral vectors has raised safety concerns about germ-line infection. Particularly, for indications such as prostate cancer and ovarian cancer, the proximity of the point of viral administration to organs of the reproductive system raises concerns regarding inadvertent germ-line transmission of genes carried by the virus vector. To evaluate the safety of in vivo adenovirus mediated gene transfer, we explored the biodistribution, persistance and potential germ-line transmission of p53-expressing adenovirus (Ad-CMV-p53). Both male and female Balb/c mice were injected with $1{\times}10^9$ PFU of Ad-CMV-p53. The PCR analysis showed that there were detectable vector sequences in liver, kidney, spleen, seminal vesicle, epididymis, prostate, ovary, and uterus. The RT-PCR analysis for detecting inserted gene, p53 showed that Ad-CMV-p53 viral RNA were present in spleen, prostate and ovary. Direct injected male and female mice of adenovirus vector into testis and ovary were mated and their of offspring were evaluated for germ-line transmission of the adenoviral vector. The PCR and RT-PCR analysis showed no evidence of germline transmission, although vector sequences were detected in DNA extracted from gonadal tissues. Real-time PCR result confirmed a significant decrease of adenovirus in gonad tissues 1 week after injection. We have also analysed the cell specific localization of viral DNA in gonad tissues by using in-situ PCR. Positive signals were detected in interstitial tissue but not in seminiferous tubule in sperm. In the case of ovary, adenovirus signal were localized to the stromal tissue, but no follicular signals were observed. Together, these data provide strong evidence that the risk of the Inadvertent germ-line transmission of vector sequences following intraperitoneal or direct injection into genito-urinary system of adenovirus is extremely low.

• Korean Journal of Adult Nursing
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• v.25 no.2
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• pp.219-230
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• 2013

Purpose: This study is reviewed of the available literature to identify the evidence of the value of Kegel exercise programs as an intervention to decrease urinary incontinence and the improvement of the quality of life following a radical prostatectomy in localized prostate cancer. Methods: We searched studies of randomized controlled trials that utilized the Kegel exercise programs with patient with a radical prostatectomy. The review was conducted electronic bibliographic database of Ovid-Medline, Embase, Scopus, KoreaMed and NDSL, etc. Of 630 publications identified, seven studies that met the inclusion criteria, and all studies analyzed by meta-analysis. To ensure the quality of the studies, we used Cochrane's Risk of Bias. Results: Kegel exercise helped patient to achieve continence more quickly (after 1, 3, 6, 12 months) than men not using Kegel exercises. Especially, Kegel exercise significantly reduced the development of urinary incontinence at one month after prostatectomy. The effectiveness of Kegel exercise after prostatectomy was found to improve the quality of life at a significant level. Conclusion: Based on available evidence, Kegel exercise that nurses can teach improved the return to continence more than usual care in men with prostatectomy urinary incontinence.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.177-183
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• 2018

Purpose : Volumetric Modulated Arc Therapy(VMAT) has the advantage of uniformly and precisely irradiating the tumor to the shape of the tumor while reducing the risk of radiation damage to normal tissues. such as brain cancer, head and neck cancer and prostate cancer, It is being used for treatment. The purpose of this study is to evaluate the usefulness of the Jaw-Tracking technique(JTT) in VMAT for brain and head and neck cancer. Materials and Methods : We selected eight patients with brain and head and neck cancer(4 Brain, 4 head and neck) who were treated with the VMAT treatment technique. Contouring information of the patient's tumor and normal organ was fused to the Rando phantom using the deformable registration of Velocity(Varian, USA). A treatment plan was developed using the Varian Eclipse(ver 15.5, Varian, USA) with the same patient actual beam parameters except for the use of jaw-tracking. As the evaluation index, the maximum dose and mean dose of target and OAR were compared and a portal dosimetry was performed for the treatment plan verification. Results : When using JTT, the relative dose of OAR decreased by 5.24 % and the maximum dose by 7.05 %, respectively, compared with the Static-Jaw technique(SJT). In the various OARs, the mean dose and maximum dose reduction ranges ranged from 0.01 to 3.16 Gy and from 0.12 to 6.27 Gy, respectively. In the case of the target, the maximum dose of GTV, CTV, PTV decreased by 0.17 %, 0.43 %, and 0.37 % in JTT, and the mean dose decreased by 0.24 %, 0.47 % and 0.47 %, respectively. Gamma analysis The JTT and SJT passing rates were $98{\pm}1.73%$ and $97{\pm}1.83%$ on the basis of 3 % / 3 mm, respectively. Comparing the doses of all OARs applied to the experiment, it was found that the use of JTT resulted in a significant decrease in dose due to additional jaw shielding besides MLC than SJT. Conclusion : In radiation therapy using VMAT treatment plan, we can apply JTT in the case of adjacent tumor and normal organs such as brain cancer and head and neck cancer, and in radiotherapy required large field and high energy caused increase leakage dose through MLC. It is considered that the target dose of PTV can be increased by lowering the dose of normal tissue surrounding the tumor.

• Progress in Medical Physics
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• v.24 no.4
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• pp.295-302
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• 2013

We estimated secondary scattered and leakage doses for intensity-modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and tomotherapy (TOMO) in patients with liver cancer. Five liver patients were planned by IMRT, VMAT and TOMO. Secondary scatter (and leakage) dose and organ equivalent doses (OEDs) are measured and estimated at various points 20 to 80 cm from the iso-center by using radiophotoluminescence glass dosimeter (RPLGD). The secondary dose per Gy from IMRT, VMAT and TOMO for liver cancer, measured 20 to 80 cm from the iso-center, are 0.01~3.13, 0.03~2.34 and 0.04~1.29 cGy, respectively. The mean values of relative OED of secondary dose of VMAT and TOMO for five patients, which is normalized by IMRT, measured as 75.24% and 50.92% for thyroid, 75.14% and 40.61% for bowel, 72.30% and 47.77% for rectum, 76.21% and 49.93% for prostate. The secondary dose and OED from TOMO is relatively low to those from IMRT and VMAT. OED based estimation suggests that the secondary cancer risk from TOMO is less than or comparable to the risks from conventional IMRT and VMAT.

• Journal of Nutrition and Health
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• v.55 no.2
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• pp.211-226
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• 2022

Choline, an essential nutrient for humans, is required for the structural integrity of the cell membranes, methyl-group metabolism, synthesis of the neurotransmitter acetylcholine, synthesis of the membrane phospholipid components of the cell membranes, and the transport of lipids and cholesterol. Choline can be synthesized in the body, but it is insufficient to meet the daily requirements and hence it must be obtained through the diet. In the United States/Canada, Australia/New Zealand, Europe, China, and Taiwan, the adequate intake (AI) and tolerable upper intake level (UL) of choline have been established, while the establishment of the 2020 Dietary Reference Intakes for Koreans (KDRI) for choline was postponed due to the lack of a choline database for Korean foods and studies on the choline intake of Koreans. However, as part of the preparation work for the 2020 DRI revision and finalization, choline intake and the possibility of disease occurrence were verified through analysis of published data. The groundwork for the subsequent establishment of a choline DRI was laid through a literature search, evaluation, and review of the literature reported from 1949 up to 2019. This can be regarded as the culmination of this project. According to the results of randomized controlled trials (RCTs), cohort studies, case-control studies, and cross-sectional observational studies in humans, approximately 400-500 mg/day of choline intake was effective in preventing liver function damage (fatty liver), neural tube damage, cardiovascular disease, breast cancer, and cognitive function improvement. The same amount of choline intake, however, also correlated with the risk of prostate and colorectal cancer. At present, there is limited information available on choline intake and health outcomes, particularly for the Korean population. More human studies, including clinical trials on the requirements and the physiological benefits associated with dietary intake, are needed to establish the KDRI for choline.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.363-368
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• 2014

Purpose : The aim of this study was to appraise properties for radiation therapy techniques and effectiveness of time and economy to a patient in the case of applying flattening filter-free (3F) and flattening filter (2F) beam to the radiation therapy. Materials and Methods : Alderson rando phantom was scanned for computed tomography image. Treatment plans for intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT) and stereotactic body radiation therapy (SBRT) with 3F and 2F beam were designed for prostate cancer. To evaluate the differences between the 3F and 2F beam, total monitor units (MUs), beam on time (BOT) and gantry rotation time (GRT) were used and measured with $TrueBeam^{TM}$ STx and Surveillance And Measurement (SAM) 940 detector was used for photoneutron emitted by using 3F and 2F. To assess temporal and economical aspect for a patient, total treatment periods and medical fees were estimated. Results : In using 3F beam, total MUs in IMRT plan increased the highest up to 34.0% and in the test of BOT, GRT and photoneutron, the values in SBRT plan decreased the lowest 39.8, 38.6 and 48.1%, respectively. In the temporal and economical aspect, there were no differences between 3F and 2F beam in all of plans and the results showed that 10 days and 169,560 won was lowest in SBRT plan. Conclusion : According as the results, total MUs increased by using 3F beam than 2F beam but BOT, GRT and photoneutron decreased. From above the results, using 3F beam can decrease intra-fraction setup error and risk of radiation-induced secondary malignancy. But, using 3F beam did not make the benefits of temporal and economical aspect for a patient with the radiation therapy.