• Radiation Oncology Journal
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• v.20 no.2
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• pp.172-178
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• 2002

Purpose : X-ray film over responds to low-energy photons in relative photon beam dosimetry because its sensor is based on silver bromide crystals, which are high-Z molecules. This over-response becomes a significant problem in clinical photon beam dosimetry particularly in regions outside the penumbra. In intensity modulated radiation therapy (IMRT), the radiation field is characterized by multiple small fields and their outside-penumbra regions. Therefore, in order to use film dosimetry for IMRT, the nature the source of the over-response in its radiation field need to be known. This study is aimed to verify and possibly improve film dosimetry for IMRT. Materials and Method : Modulated beams were constructed by a combination of five or seven different static radiation fields using 6 MeV X-rays. In order to verify film dosimetry, we used X-ray film and an ion chamber were used to measure the dose profiles at various depths in a phantom. In addition, in order to reduce the over-response, 0.01 inch thick lead filters were placed on both sides of the film. Results : The measured dose profiles showed a film over-response at the outside-penumbra and low dose regions. The error increased with depths and approached 15% at a maximum for the field size of $15{\times}15cm^2$ at 10 cm depth. The use of filters reduced the error to 3%, but caused an under-response of the dose in a perpendicular set-up. Conclusion : This study demonstrated that film dosimetry for IMRT involves sources of error due to its over-response to low-energy Photons. The use of filers can enhance the accuracy in film dosimetry for IMRT. In this regard, the use of optimal filter conditions is recommended.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.410-414
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• 1995

Adaptive response induced by low dese .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray (1-cGy) followed by high doses of r-ray irradiation (0,1,2,3,5,7 and 9Gy for chlnogenic assay or 1.5Gy for micronucleus assay) with various time intervals. Survival fractions of cells in both low dose-irradiated and unirrated groups were analyzed by clonogenic assay. Surviva fractions of low dose-irradiated in cell survival was maximum when low and high dose irradiation time interval was 4 hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enutained from survival fractions analyzed by clonogenic assay, maximum when low and high dose irradiation time interval was 4hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enumerated in both low dose-irradiated and unirradiated groups. In consiststent with the result obtained from survival fractions analyzed by clonogenic assay, maximum reduction in frquencies of micronuclei was observed when low dose radiation was given 4 hr prior to high response to subsequent high dose .gamma.-ray irradiation in human cervical carcinomal cells. Our data suggest that one of the possible mechanisms of adaptive response induced by low dose rediation is the increase in repair of DNA double strand breaks in low dose radiation-adapted cells.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3945-3948
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• 2013

Background: Lung cancer is the leading cause of cancer death, late diagnosis being the main obstacle to improving the outcomes with stage at diagnosis as an important prognostic factor. Relationships between ABO blood groups and risk of benign or malignant diseases have been observed and in this study, we aimed to investigate whether they might affect prognosis and response to chemoradiotherapy in patients with local advanced non-small cell lung cancer (NSCLC). Materials and Methods: Eighty-one patients with non-metastatic local advanced NSCLC were included in the study. ABO blood groups were A in 45 (55.6%), B in 7 (8.6%), AB in 8 (9.9%), and O in 21 (25.9%) patients. The patients were also divided two groups according to blood group A (45 patients) and non-A (B, AB and O; 36 patients). Response to chemoradiotherapy was complete remission in 10 (12.3%), disease regression in 42 (51.9%), stable disease in 12 (14.8%), and disease progression in 17 (21.0%) patients. Results: There was no significant difference among ABO blood group categories or between patients with A blood group and those with non-A blood group in terms of responses to chemoradiotherapy (p>0.05). There were also no significant differences regarding overall and disease-free survival rates. Conclusion: The ABO blood group system has no significant effect on prognosis and response to chemoradiotherapy in patients with non-metastatic NSCLC.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.63-70
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• 2011

Purpose: To evaluate the extent of pain response and objective response to palliative radiotherapy (RT) for bone metastases from hepatocellular carcinoma according to RT dose. Materials and Methods: From January 2007 to June 2010, palliative RT was conducted for 103 patients (223 sites) with bone metastases from hepatocellular carcinoma. Treatment sites were divided into the high RT dose and low RT dose groups by biologically effective dose (BED) of 39 $Gy_{10}$. Pain responses were evaluated using the numeric rating scale. Pain scores before and after RT were compared and categorized into 'Decreased', 'No change' and 'Increased'. Radiological objective responses were categorized into complete response, partial response, stable disease and progression using modified RECIST (Response Evaluation Criteria In Solid Tumors) criteria; the factors predicting patients' survival were analyzed. Results: The median follow-up period was 6 months (range, 0 to 46 months), and the radiologic responses existed in 67 RT sites (66.3%) and 44 sites (89.8%) in the high and low RT dose group, respectively. A dose-response relationship was found in relation to RT dose (p=0.02). Pain responses were 75% and 65% in the high and low RT dose groups, respectively. However, no statistical difference in pain response was found between the two groups (p=0.24). There were no differences in the toxicity profiles between the high and low RT dose groups. Median survival from the time of bone metastases diagnosis was 11 months (range, 0 to 46 months). The Child-Pugh classification at the time of palliative RT was the only significant predictive factor for patient survival after RT. Median survival time was 14 months under Child-Pugh A and 2 months under Child-Pugh B and C. Conclusion: The rate of radiologic objective response was higher in the high RT dose group. Palliative AT with a high dose would provide an improvement in patient quality of life through enhanced tumor response, especially in patients with proper liver function.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.287-291
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• 2016

Cervical cancer is one of the most common gynecological cancers in Iranian women. This study was initiated to assess whether the combination of paclitaxel and cisplatin with radiation might feasible for these patients. The aim was to assess tumor response and toxicity of weekly cisplatin and paclitaxel along with radiotherapy in the treatment of cervical cancer. Women with primary untreated squamous cell carcinoma of the cervix with FIGO stages IB2 to IIIB were treated with weekly injections of cisplatin 30 mg/m2 and paclitaxel 35 mg/m2 for 5-6 weeks along with radiotherapy. A total of 25 patients were enrolled in this study who completed the intended treatment. Disease was assessed prior to treatment by pelvic examination and contrast enhanced MRI of the abdomen and pelvis. Response was assessed 1 month after completion of treatment by physical examination and 3 months after also by MRI.Toxicity was assessed and was graded using RTOG grading. There was a complete response rate of 84% after 3 months. The major toxicity was grade 1 and 2 anemia (92%). The mean duration of treatment was 58 days. In conclusion, combination chemotherapy with cisplatin and paclitaxel along with radiotherapy in patients with locally advanced squamous cell carcinoma of cervixwas well tolerated, in contrast to other studies, but it seems that there was no increase in tumor response and progression free survival with this treatment regimen.

• Radiation Oncology Journal
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• v.8 no.1
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• pp.73-77
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• 1990

From January 1981 to December 1989, total 42 patients with atelectasis from lung cancer were treated with radiation therapy at the Department of Therapeutic Radiology in Kyung Hee University Hospital. The reexpansion of atelectasis after radiotherapy of the lung was evaluated retrospectively, utillzing treatment records and follow-up chest radiographs. Of the patients with non-small cell carcinoma of the lung, the response rate was $62\%$ (21/34). Patient with small cell carcinoma showed a $75\%$ (6/8) response rate. There appears to be some evidence of a relationship of total tumor dose versus response of atelectasis; radiation dose over 40 Gy (1337 ret), had a favorable effect on the rate of response compared with that below 40 Gy (1297 ret), $70\%$(21/30) and $50\%$ (6/12), respectively (p<0.01). Total response rate (partial and complete responses) of all patients was $64\%$ (27/42). Franction size was not contributed to the difference of response rates between small fraction ($180\~200$ cGy) and large fraction (300 cGy), $53\%$ (14/22) and $65\%$ (13/20), respectively. The results of this study suggest that radiation therapy has a definite positive role in management of atelectasis caused by lung cancer, especially in inoperable non-small cell carcinoma.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.10-15
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• 2001

Purpose : This is a retrospective study to evaluate the results of radiation therapy in nasopharyngeal carcinoma. Materials and Methods : From September 1989 to October 1996, 19 patients with nasopharyngeal carcinoma completed planned radiation therapy course. Stages were 1 in 2 patients, II in 6, III in 2 IV in 9 patients, respectively. Pathology was squamous cell carcinoma in 5 patients, undifferentiated cell carcinoma in 14 patients. Fourteen patients were treated with radiation therapy only. Five patients received chemotherapy. The follow-up period ranged from 5 months to 115 months with a median of 33 months. Follow-up was possible in all patients. Results : Responses to radiation therapy were complete response in 15 patients, partial response in 2, and no response in 2, respectively. Patterns of failure were as follows : locoregional recurrence in 6 patients and distant metastasis in 4 patients. The sites of distant metastasis were bone, liver and lung. Five year survival rate was $47.8\%$ and five year disease free survival rate was $48.1\%$. Stage, T-stage, N-stage, central nervous system involvement, pathology type, performance status, response, radiation dose, chemotherapy were not significant prognostic factors. Conclusion : 5-year survival rate was $47.8\%$ and 5-year disease free survival rate was $48.1\%$. The advances in radiation therapy techniques and chemotherapy are needed.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.35-43
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• 2020

Purpose: This retrospective study compares higher-dose whole-brain radiotherapy (hdWBRT) with reduced-dose WBRT (rdWBRT) in terms of clinical efficacy and toxicity profile in patients treated for primary central nervous system lymphoma (PCNSL). Materials and Methods: Radiotherapy followed by high-dose methotrexate (HD-MTX)-based chemotherapy was administered to immunocompetent patients with histologically confirmed PCNSL between 2000 and 2016. Response to chemotherapy was taken into account when prescribing the radiation dose to the whole brain and primary tumor bed. The whole brain dose was ≤23.4 Gy for rdWBRT (n = 20) and >23.4 Gy for hdWBRT (n = 68). Patients manifesting cognitive disturbance, memory impairment and dysarthria were considered to have neurotoxicity. A median follow-up was 3.62 years. Results: The 3-year overall survival (OS) and progression-free survival (PFS) were 70.0% and 48.9% with rdWBRT, and 63.2% and 43.2% with hdWBRT. The 3-year OS and PFS among patients with partial response (n = 45) after chemotherapy were 77.8% and 53.3% with rdWBRT, and 58.3% and 45.8% with hdWBRT (p > 0.05). Among patients with complete response achieved during follow-up, the 3-year freedom from neurotoxicity (FFNT) rate was 94.1% with rdWBRT and 62.4% with hdWBRT. Among patients aged ≥60 years, the 3-year FFNT rate was 87.5% with rdWBRT and 39.1% with hdWBRT (p = 0.49). Neurotoxicity was not observed after rdWBRT in patients aged below 60 years. Conclusion: rdWBRT with tumor bed boost combined with upfront HD-MTX is less neurotoxic and results in effective survival as higher-dose radiotherapy even in partial response after chemotherapy.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.58-62
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• 2003

Purpose: To evaluate the efficacy of positron emission tomography with 2-[F-18] fluoro-2-deoxy-D-glucose in discrimination of response in the nasopharyngeal carcinoma patients who treated with radiotherapy. Methods and Materials: Twenty-four patients who underwent FDG-PET scan before and after radiotherapy for no disseminated head and neck carcinoma at the Asan Medical Center between August 2001 and September 2002 were evaluate by prospective analysis. First FDG-PET scan performed before radiotherapy within 1 month, and second FDG-PET scan performed 1 month after radiotherapy. FDG-PET images were analyzed by standard uptake value (SUV). Follow-up period was more than 6 months. Results: The pretreatment SUV was 3.4-14.0 (median: 6.0) and posttreatment SUV was ground level-7.7 (median: 2.0). The overall sensitivity and specicity of FDG-PET to evaluate residual tumors in the nasopharyngeal carcinoma patients were 94% and 94%. Conclusion: FDG-PET is effective in evaluation of radiation response in the nasopharyngeal carcinoma. We think that the timing of one month after finished radiotherapy FDG-PET scan was not too fast to evaluation of radiation response.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.35-39
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• 1988

From Jan.1984 to Dec. 1986, 90 patients with lung cancer were treated at the Department of Radiation Therapy in Hanyang University Hospital. Histopathologically, 67 cases of them were the squamous cell carcinoma,7 cases were the adenocarcinoma, 4 cases were the large cell undiffe rentiated carcinoma and 12 cases were the small cell carcinoma. Among the 78 patients with non small cell carcinoma, 50 patients had received radiation dosage above 4000 cGy.40 patient had follow up from 17 months to 53 months. The complete response rate was $7.3\%$ and partial response rate was $68.3\%$. Overall survival at 1, 2 and 3 years were $47.5\%,\;23.5\%\;and\;6.3\%$ respectively. None was survived longer than 38 months. Median survival was 12.2 month for 40 patient and 9 month for stage III, M1 group and 9.5 month for stage III, MO group. In M1 patient no survival was seen after 2 years while in M0 patient $23.3\%$ survival was seen.