• Radiation Oncology Journal
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• v.27 no.1
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• pp.10-14
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• 2009

Purpose: This study was designed to evaluate the effectiveness and prognostic factors for patients treated with postoperative radiation therapy following surgery or with radiation therapy alone for squamous cell carcinoma of the esophagus. Materials and Methods: We retrospectively analyzed 132 esophageal cancer patients treated with postoperative radiation therapy following surgery or patients who were treated with radiation therapy alone at our institution from 1989 to 2006. Thirty-five patients had stage II disease, 88 patients had stage III disease and nine patients had stage IV disease. Tumors were located at the upper esophagus in 18 patients, the mid esophagus in 81 patients and the distal esophagus in 33 patients. Sixty patients were treated with radiation therapy alone and 72 patients were treated with postoperative radiation therapy following surgery. Eight patients received a dose less than 40 Gy and 78 patients received a dose of 40 to 50 Gy. The remaining 46 patients received a dose of 50 to 60 Gy. The majority of patients who underwent postoperative radiation therapy received a dose of 45 Gy. Results: Actuarial survival rates for all of the patients at two years and five years were 24% and 5%, respectively. The median survival time was 11 months. Survival rates for patients who underwent postoperative RT at two years and five years were 29% and 8%, respectively. The corresponding survival rates for patients who received radiation alone were 18% and 2%, respectively. Survival rates at two years and five years were 43% and 15% for stage II disease, 22% and 2% for stage III disease and 0% and 0% for stage IV disease, respectively; these findings were statistically significant. Two-year survival rates for patients with upper, middle and distal esophageal cancer were 19, 29% and 22%, respectively. Although there was a trend of slightly better survival for middle esophageal tumors, this finding was not statistically significant. Complete response to radiation was achieved in 13 patients (22%) and partial response to radiation was achieved in 40 patients (67%) who received radiation alone. No response to radiation was noted in seven patients (12%). A statistically significant difference in survival rates was seen between patients that had a complete response and patients that had a partial response. Two-year survival rates for patients that had a complete response versus patients that had a partial response were 31% and 17%, respectively. There were no survivors for patients with no response as determined at two-year follow-up. Conclusion: We conclude that radiation therapy is an effective treatment for esophageal cancer. Stage and response to radiation therapy were noted to be prognostic factors. A more effective treatment modality is needed to improve long term survival because of the relatively dismal prognosis for this tumor.

• Korean Journal of Head & Neck Oncology
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• v.8 no.1
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• pp.37-43
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• 1992

In order to improve the control of large unresectable(>6cm) and fixed N3(TNM-UICC) metastatic neck nodes, local hyperthermia(HT) has been combined with radiation therapty (RT) in Yonsei cancer center. From April 1985 to april 1988, a total of 18 patients of head and neck cancer with metastatic large unresectable and fixed cervical neck nodes who underwent combined RT and HT were analyzed. Of 18 patients, complete response rate was 39% (7 pt.) partial response 39% (7 pt.) and overall response rate was 78%. Acute side effects of these combined modalities were found in 8 patients and which were mainly cutaneous reaction such as erythema, dry and moist desquamation but recovered spontaneously in all patients after treatment. Factors of maximum tumor temperature above $43^{\circ}\C$ and MDF(multiple daily fractionation) showed more favorable response rate but not statistically sinificant. Two year actuarial survival rate of all patients was 35.4%.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.166-167
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• 2009

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• Radiation Oncology Journal
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• v.2 no.2
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• pp.237-243
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• 1984

Thirty Patients with loco-regional recurrence following curative surgery for adenocarcinoma of the rectum were retrospectively evaluated to determine factors influencing survival and the efficacy of radiation therapy. In this review of 30 patients undergoing radiation therapy, more than 50 percent(17/30) had definite symptomatic and objective response. Ninety percent of patients(27/30) received significant palliation. Over all 2 year survival rate was $7.4\%$ and their median survival was 13.0 months. Grade of response and Sex were statistically related to survival.

• Journal of Radiation Protection and Research
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• v.44 no.3
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• pp.97-102
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• 2019

Background: Dose rate meters are the most widely used, and perhaps one of the most important tools for the measurement of ionising radiation. They are often the first, or only, device available to a user for an instant check of radiation dose at a certain location. Throughout the world, radiation safety practices rely strongly on the output of these dose rate meters. But how well do we know the quality of their output? Materials and Methods: This review is based on the measurements 1,158 commercially available dose rate meters of 116 different makes and models. Expected versus the displayed dose patterns and consistency was checked at various dose rates between $5{\mu}Gy{\cdot}h^{-1}$ and $2mGy{\cdot}h^{-1}$. Samples of these meters were then selected for further investigation and were exposed to radiation sources covering photon energies from 50 keV to 1.5 MeV. The effect of detector orientation on its reading was also investigated. Rather than focusing on the angular response distribution that is often reported by the manufacturer of the device, this study focussed on the design ergonomics i.e. the angles that the operator will realistically use to measure a dose rate. Results and Discussion: This review shows the scope and boundaries of the ionising radiation dose rate estimations that are made using commonly available meters. Observations showed both inter and intra make and model variations, occasional cases of instrument failure, instrument walk away, and erroneous response. Conclusion: The results indicate the significance of selecting and maintaining suitable monitors for specific applications in radiation safety.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.1008-1009
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• 2005

In order to screen ionizing radiation induced early-response genes, we employed subtractive hybridization method and isolated a metabolism associated gene. The gene expression was very sensitive to ionizing radiation as revealed by a rapid induction of its messenger RNA. We characterized the function of this gene in radiation response. This gene activated p53 and enhanced cell killing effect of ionizing radiation. This effect was attributable to p53 phosphorylation and transcriptional activation.

• Journal of Radiation Protection and Research
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• v.22 no.2
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• pp.127-133
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• 1997

In this study an EGS4 simulation code was used to calculate real energy spectrum from measured ${\gamma}$-ray energy spectrum obtained using 2-dimensional radiation monitoring system. As a result, the $39{\times}39$ response matrix was calculated the energy range of 0.1 to 2 MeV which energy interval of 50 keV The real energy spectrum for Co-60 radioisotope was calculated using inverse of response matrix. It was confirmed that the calculated response matrix was useful to the analysis of the measured energy spectrum for the radiation monitoring system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.516-523
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• 1998

Radiation efficiency of a cylindrical shell whose surface vibrates under harmonic distribution is investigated by theoretical solutions and Boundary Element Method. The vibration modes of a cylindrical shell is determined from experiment and is compared with the result of Finite Element Method. Harmonic vibration response of the cylindrical shell under the point excitation and the radiation phenomena from its response is analyzed by Finite Element Method and Boundary Element Method.

• Radiation Oncology Journal
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• v.34 no.4
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• pp.305-312
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• 2016

Purpose: The objective of this prospective study was to evaluate the relationship between the circulating lymphocyte subpopulation counts during preoperative chemoradiotherapy (CRT) and tumor response in locally advanced rectal cancer. Materials and Methods: From August 2015 to June 2016, 10 patients treated with preoperative CRT followed by surgery were enrolled. Patients received conventional fractionated radiotherapy (50.4 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. The absolute blood lymphocyte subpopulation was obtained prior to and after 4 weeks of CRT. We analyzed the association between a tumor response and change in the lymphocyte subpopulation during CRT. Results: Among 10 patients, 2 (20%) had evidence of pathologic complete response. In 8 patients with clinically node positive, 4 (50%) had nodal tumor response. All lymphocyte subpopulation counts at 4 weeks after CRT were significantly lower than those observed during pretreatment (p < 0.01). A high decrease in natural killer (NK) cell, count during CRT (baseline cell count - cell count at 4 weeks) was associated with node down staging (p = 0.034). Conclusion: Our results suggest that the change of lymphocyte subset to preoperative CRT may be a predictive factor for tumor response in rectal cancer.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.212-217
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• 1997

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of ${\gamma}$-rays (0.01 Gy) 4 or 20 hrs prior to high dose ${\gamma}$-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose .gamma.-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-.betha.-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose ${\gamma}$-ray irradiation to high dose ${\gamma}$-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.