• Journal of Life Science
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• v.22 no.11
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• pp.1558-1570
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• 2012

In radiation biology, analysis of various mechanisms in response to radiation has been accomplished with the use of model organisms. These model organisms are powerful tools for providing a biologically intact in vivo environment to assess physiological and pathophysiological processes affected by radiation. Accumulated data using these models have been applied to human clinical studies (including the evaluation of radiotherapeutic efficacy) and discovery of radiotherapy reagents. However, there are few studies to provide overall integrated information about these useful model organisms. Thus, this review summarizes the results of radiation biology studies using four well-known model organisms: yeast, Caenorhabditis elegans, Drosophila melanogaster, and mice.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.199-204
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• 2001

Purpoe : To find the optimal values of total arc degree to protect the normal brain tissue from high dose radiation in stereotactic radiotherapy planning. Methods and Materials : With Xknife-3 planning system & 4 MV linear accelerator, the authors planned under various values of parameters. One isocenter, 12, 20, 30, 40, 50, and 60 mm of collimator diameters, $100^{\circ},\;200^{\circ},\;300^{\circ},\;400^{\circ}C,\;500^{\circ},\;600^{\circ}$ or total arc degrees, and $30^{\circ}\;or\;45^{\circ}$ or arc intervals were used. After the completion of planning, the plans were compared each other using $V_{50}$ (the volume of normal brain that is delivered high dose radiation) and integral biologically effective dose. Results : At $30^{\circ}$ of arc interval, the values of $V_{50}$ had the decreased pattern with the increase of total arc degree in any collimator diameter. At 45 arc interval, up to $400^{\circ}$ of total arc degree, the values of $ V_{50}$ decreased with the increase of total arc degree, but at $500^{\circ}\;and\;600^{\circ}$ of total arc degrees, the values increased. At $30^{\circ}$ of arc interval, integral biologically effective dose showed the decreased pattern with the increase of total arc degree in any collimator diameter. At $45^{\circ}$ arc interval with less than 40 mm collimator diameter, the integral biologically effective dose decreased with the increase of total arc degree, but with n and n mm or collimator diameters, up to $400^{\circ}$ or total arc degree, integral biologically effective dose decreased with the increase of total arc degree, but at $500^{\circ}\;and\;600^{\circ}$ of total arc degrees, the values increased. Conclusion : In the stereotactic radiotherapy planning for brain lesions, planning with $400^{\circ}$ of total arc degree is optimal. Especially, when the larger collimator more than 50 mm diameter should be used, the uses of $500^{\circ}\;and\;600^{\circ}$ of total arc degrees make the increase of$V_{50}$ and integral biologically effective dose. Therefore stereotactic radiotherapy planning using $400^{\circ}$ of total arc degree can increase the therapeutic ratio and produce the effective outcome in the management of personal and mechanical sources in radiotherapy department.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.141-145
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• 1999

Purpose : Granisetron is a potent, the most selective 5-HT3 receptor antagonist and is reported to b effective in treatment of radiation-induced emesis. The antiemetic efficacy and safety of oral granisteron was evaluated in patients with receiving highly emetogenic treatment by conventional fractionated irradiation. Materials and Methods : Patients with various cancers who were being treated with irradiation were accrued into the present study. The intensity of nausea was evaluated on first 24 hours and on day-7 by patients according to the degree of interference with normal daily life as followings; a) none; b) present but no interference with normal daily life (mild): c) interference with normal daily life (moderate): and d) bedridden because of nausea (severe). Non or mild state was considered to indicate successful treatment. The efficacy of antiemetic treatment was graded as follows; a) complete response; no vomiting, no worse than mild nausea and receive no rescue antiemetic therapy over the 24h period, b) major response; either one episode of vomiting or moderate/severe nausea or had received rescue medication over 24h period, or any combination of these, c) minor response; two to four episodes of vomiting over the 24h period, regardless of nausea and rescue medication, d) failure; more than four medication. The score of the most symptom was recorded and the total score over 24 hours was summarized. The complete or major response was considered to indicate successful treatment. Results : A total of 10 patients were enrolled into this study, and all were assessable for efficacy analysis. Total nausea control was achieved in 90$\%$ (9/10:none=60$\%$ plus mild=30$\%$) of total patients after 7 days. The control of vomiting by granisteron was noted in seven patients (70$\%$) of complete response and three (30$\%$) of major response with a hundred-percent successful treatment over 7 days. The minor response or treatment failure were not observed. No significant adverse events or toxicities from granisetron were recorded in patient receiving granisetron. Conclusion : We concluded that granisetron is a highly effective antiemetic agent in controlling radiotherapy-induced nausea or vomiting with a minimal toxicity profile.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.17-21
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• 2005

Purpose : To evaluate the voices of irradiated patients with early glottic carcinoma and to compare these with the voices of healthy volunteers. Materials and Methods : The voice samples (sustained vowel) of seventeen male patients who had been irradiated for T1a glottic squamous carcinoma at least 1 year prior to the study were analyzed with objective voice analyzer (acoustic voice analysis, aerodynamic test, and videostroboscopic analysis) and compared with those of a normal group of twenty age- and sex-matched volunteers. Average fundamental frequency, jitter, shimmer, and noise-to-harmonic ratio were obtained for acoustic voice analysis. Maximal phonation time, mean flow rate, intensity, subglottic pressure, glottal resistance, glottal efficiency, and glottal power were obtained for aerodynamic test. Results : The irradiated group presented higher values of shimmer in acoustic voice analysis. There was no significant difference between two groups in other parameters. Conclusion : In this study all the objective voice parameters except shimmer were no4 significantly different between the irradiated group and the control group. These results suggest that the voice quality is minimally affected by radiation therapy for 71 a glottic carcinoma.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.565-570
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• 2016

Radioactive iodine($^{131}I$) treatment reduces recurrence and increases survival in patients with differentiated thyroid cancer. However, it is important in terms of radiation safety management to measure the radiation dose rate generated from the patient because the radiation emitted from the patient may cause the exposure. Research methods, it measured radiation dose-rate according to the elapsed time from 1 m from the upper abdomen of the patient by intake of radioactive iodine. Directly comparing the changes over time, high dose rate sensitivity and efficiency is statistically significant, and higher chamber than GM counter(p<0.05). Low dose rate sensitivity and efficiency in the chamber had lower levels than gm counter, but not statistically significant(p>0.05). In this study confirmed the characteristics of calibrated ionization chamber and GM counter according to the radiation intensity during high-dose radioactive iodine therapy by measuring the accurate and rapid radiation dose rate to the patient explains, discharged patients will be reduced to worry about radiation hazard of family and others person.

• Radiation Oncology Journal
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• v.15 no.4
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• pp.315-319
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• 1997

Purpose : To evaluate the role of curative radiotherapy and salvage surgery in Patients with T1 T2 glottic canter. Materials and Method : Between June 1989 and December 1994, 23 patients with early glottic cancer, 18 with T1N0M0 and 5 with T2N0M0, were treated with radiotherapy at Gyeongsang National University Hospital All Patients were male. Median follow-up period was 46 months, and $100\%$ were observed for at least 3 years. Results : Actuarial survival rates at 5 years were $84.3\%$ for 23 patients. The 5-year actuarial survival rates were $94.4\%$ for T1 and $53.3\%$ for 72(P=0.05) The 5-rear local control rates was $70.0\%$ for T1 and $60.0\%$ for T2 (P=0.44). Of 8 Patients with treatment failure, 6 patients $(75.0\%)$ were salvaged with surgery. After surgical salvage, the 5-year local control rates were $87.2\%$ for T1 and $80.0\%$ for T2(p=0.55). Conclusion : In early stage (Stage I and II) glottic cancer, curative radiotherapy can be a treatment of choice and surgery reserved for salvage of radiotherapy failure.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.23-30
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• 2015

Purpose : External markers respiratory movement measuring device (RPM; Real-time Position Management, Varian Medical System, USA) Liver Cancer Radiation Therapy Respiratory gated with respiratory signal with irradiation time and the actual research by analyzing the respiratory phase with the breathing motion measurement device respiratory tuning evaluate the accuracy of radiation therapy Materials and Methods : May-September 2014 Novalis Tx. (Varian Medical System, USA) and liver cancer radiotherapy using respiratory gated RPM (Duty Cycle 20%, Gating window 40% ~ 60%) of 16 patients who underwent total when recording the analyzed respiratory movement. After the breathing motion of the external markers recorded on the RPM was reconstructed by breathing through the acts phase analysis, for Beam-on Time and Duty Cycle recorded by using the reconstructed phase breathing breathing with RPM gated the prediction accuracy of the radiation treatment analysis and analyzed the correlation between prediction accuracy and Duty Cycle in accordance with the reproducibility of the respiratory movement. Results : Treatment of 16 patients with respiratory cycle during the actual treatment plan was analyzed with an average difference -0.03 seconds (range -0.50 seconds to 0.09 seconds) could not be confirmed statistically significant difference between the two breathing (p = 0.472). The average respiratory period when treatment is 4.02 sec (${\pm}0.71sec$), the average value of the respiratory cycle of the treatment was characterized by a standard deviation 7.43% (range 2.57 to 19.20%). Duty Cycle is that the actual average 16.05% (range 13.78 to 17.41%), average 56.05 got through the acts of the show and then analyzed% (range 39.23 to 75.10%) is planned in respiratory research phase (40% to 60%) in was confirmed. The investigation on the correlation between the ratio Duty Cycle and planned respiratory phase and the standard deviation of the respiratory cycle was analyzed in each -0.156 (p = 0.282) and -0.385 (p = 0.070). Conclusion : This study is to analyze the acts after the breathing motion of the external markers recorded during the actual treatment was confirmed in a reproducible ratios of actual treatment of breathing motion during treatment, and Duty Cycle, planned respiratory gated window. Minimizing an error of the treatment plan using 4DCT and enhance the respiratory training and respiratory signal monitoring for effective treatment it is determined to be necessary.

• Progress in Medical Physics
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• v.18 no.4
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• pp.202-208
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• 2007

Various techniques were evaluated to determine the best method for reducing small bowel involvement in pelvic irradiation. Fourteen patients receiving radiation in pelvic area were enrolled for this study. Five sets of small bowel images were obtained. Patients were positioned on a simulation couch with full bladder in prone and supine positions and 2 sets of images were taken. Then they were asked to empty their bladder and 2 sets of images were taken in prone and supine positions. A belly board device (BBD) was placed and one set of images was obtained. Using a software, the area of small bowel inside treatment field was contoured, measured, and analyzed. In both full and empty bladder cases, small bowel area reduction was observed in prone position as compared to supine position. Especially statistically significant reduction is noted in lateral film. An average decreases of 13% in PA and 26% in lateral direction were noted with bladder distention as compared to empty bladder. With the use of BBD for empty bladder, a significant reduction of $62.8{\pm}27.1%$ and $63.1{\pm}32.9%$ in PA and lateral directions were observed as compared to without BBD in prone position, respectively. In conclusion, the best sparing of small bowel concerning the area included in the treatment fields was achieved with BBD in prone position with empty bladder. However, further reduction is expected if the bladder was filled fully because the analysed data with empty vs full bladder study shows increased sparing of small bowel with distended bladder.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.225-232
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• 2014

Underwent on modified radical mastectomy(MRM) and radiation therapy, it affects increasing rates of chronic morbidity, because of including chest wall and internal mammary nodes(IMNs). It causes the high absorbed dose on heart and ipsilateral lung. Thus in this study, we compared dose distributions through utilizing the intensity modulated radiation therapy(IMRT) and the volumetric modulated arc therapy(VMAT). We selected 10 breast cancer patients at random who took MRM and radiation therapy. Treatment plannings were done by using IMRT and VMAT from each patient ranging supraclavicular lymphnodes(SCL) and IMNs. After that we analysed the planning target volume(PTV)'s conformity and absorbed doses on heart and lungs. As a results, PTV conformities were indicated the same patten(p<0.05) in both plans. In case of Lt breast cancer patients, the dose maximum regions of the heart were more lesser in VMAT technique rather than the IMRT(p<0.05). Also, the maximum dose areas of lungs were lesser in VMAT technique rather than the IMRT(p<0.05). Therefore, it would be safe to say that it is more effective way to adapt the VMAT technique than IMRT in such cases like involve IMNs in breast cancer patients.

• Progress in Medical Physics
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• v.21 no.2
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• pp.183-191
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• 2010

In this study, the patient with localized prostate cancer who had previously been treated at Ajou University Hospital was randomly selected since March, 2009. we performed IMRT and 2RA plans and the same dose objectives were used for CTVs, PTVs, rectum, bladder, and femoral head of the respective plans. Arc optimizations and dose calculations were performed using Eclipse versions 8.6. In this paper, we evaluated the performance of IMRT and RA plans to investigate the clinical effect of RA for prostate cancer case. In our comparison of treatment techniques, RA was found to be superior to IMRT being better dose conformity of target volume. As for the rectum and bladder, RA was better than IMRT at decreasing the volume irradiated. RA has the ability to avoid critical organs selectively through applied same dose constraints while maximally treating the target dose. Therefore, this result suggests that there should be less rectal toxicity with RA compared with IMRT, with no compromise in tumor margin. These findings, which show more favorable rectal, bladder, and femoral head DVHs with RA, imply that should not result in excess risk of toxicity when this technique is used. Many experiences with RA have shown not only dosimetric advantage, but also improved clinical toxicity when comparing with IMRT. The main drawbacks of RA are the more complex and time-consuming treatment planning process and the need for more exact physics quality assurance (QA).