• Journal of Radiation Protection and Research
• /
• v.17 no.1
• /
• pp.21-30
• /
• 1992

The frequencies of KCCH cyclotron neutron (30 cGy/min) or $^{60}Co\;{\gamma}-rays$ (210 cGy/min)-induced asymmetrical interchanges (dicentrics and centric rings) and acentric fragments (deletion) at several doses were measured in the normal human peripheral blood lymphocytes Chromosome aberrations were scored at the first nitosis after stimulation with phytohemagglutinin. The neutron and y-ray data were analysed on linear, power-law, quadratic and linear-quadratic model . When the dicentrics and centric rings of ${\gamma}-rays$ datas were pooled and fitted to these model, good fits were obtained to power-law $[Y=(5.81{\pm}1.96){\times}10^6D^{1.93+0.06},\; P=0.931]$, quadratic $[Y=(3.91{\pm}0.09){\times}10^{-6}D^2,\;P=0.972]$ an linear-Quadrati model $[Y=(6.55{\pm}6.83){\times}10^{-5}D+(3.72{\pm}0.22){\times}10^{-6}D^2\; P=0.922]$, except for linear model (P=0.067) As in the case of neutron data, the best fit was obtained to the linear model $(Y=(6.12{\pm}0.17){\times}10^{-3}\;D-0.22,\;P=0.987]$ and good fits were obtained to power-law$[Y=(5.36{\pm}3.02) {\times}10^{-4}D^{1.42+0.11},\; P=0.601]$ and linear-quadratic model$[Y=(2.43{\pm}0.70){\times}10^{-3}D+(1.21{\pm}0.39){\times}10^{-7}D^2$, \;P=0.415], except for quadratic model (P<0.005). The relative biological effectiveness (RBE) of neutron compared with y-ray was estimated by best fitting model. In the asymmetrical interchanges range between 0.1 and 1.5 per cell, the RBE was found to be $2.714{\pm}0.408$.

• Applied Microscopy
• /
• v.37 no.2
• /
• pp.83-91
• /
• 2007

The present study examined the epidermal changes of adhesive disks which occur during attachment in Parthenocissus tricuspidata using scanning and transmission electron microscopy. Several adhesive disks, each covered with a bract, develop from the shoot apical meristem during early development. In the initial stage, the adhesive disks are club-shaped and their upper and lower epidermis are indistinguishable. However, in the actively growing stage, they become spherical and both epidermis are clearly differentiated into the adventitious roots. Prior to wall attachment, the adhesive disks exhibit adaxial convex and abaxial concave shapes, and electron-dense substances are abundant in the vacuoles of epidermal cells. The peripheral area of the adhesive disk is adhered first to the wall surface, while the central area is drawn inward in a vacuum-like state during attachment. As the attachment progresses and the electron-dense substances continue to discharge, the upper and lower epidermis rapidly undergo deterioration and the disks shrink considerably. At this stage, structural changes of the lower epidermis occur much faster than in the upper one. The discharged substance is accumulated on the wall surface, and this aids the attachment of adhesive disks on the wall for long periods. In this manner, the shape and structure of the adhesive disk epidermis change drastically from initial growth to the mature stage. Further, the role of electron-dense substance and shrinkage of the disk during attachment has been discussed in Parthenocissus tricuspidata.

• Radiation Oncology Journal
• /
• v.24 no.1
• /
• pp.1-10
• /
• 2006

Puroose: To present preliminary results of intensity-modulated radiotherapy (IMRT) using the simultaneous modulated accelerated radiation therapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). Materials and Methods: Twenty patients who underwent IMRT for non-metastatic NPC at the Asan Medical Center between September 2001 and December 2003 were prospectively evaluated. IMRT was delivered using the 'step and shoot' SMART technique at prescribed doses of 72 Gy (2.4 Gy/day) to the gross tumor volume (GTV), 60 Gy (2 Gy/day) to the clinical target volume (CTV) and metastatic nodal station, and 46 Gy (2 Gy/day) to the clinically negative neck region. Eighteen patients also received concurrent chemotherapy using cisplatin once per week. Results: The median follow-up period was 27 months. Nineteen patients completed the treatment without interruption; the remaining patient interrupted treatment for 2 weeks owing to severe pharyngitis and malnutrition. Five patients (25%) had RTOG grade 3 mucositis, whereas nine (45%) had grade 3 pharyngitis. Seven patients (35%) lost more than 10% of their pretreatment weight, whereas 11 (55%) required intravenous fluids and/or tube feeding. There was no grade 3 or 4 chronic xerostomia. All patients showed complete response. Two patients had distant metastases and loco-regional recurrence, respectively. Conclusion: IMRT using the SMART boost technique allows parotid sparing, as shown clinically and by dosimetry, and may also be more effective biologically. A larger population of patients and a longer follow-up period are needed to evaluate ultimate tumor control and late toxicity.

• Radiation Oncology Journal
• /
• v.29 no.1
• /
• pp.36-43
• /
• 2011

Purpose: To evaluate the effectiveness of radiation therapy (RT) for hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) and to analyze the prognostic factors. Materials and Methods: From December 2004 to April 2009, 70 patients who had HCC with PVTT were treated with RT at Keimyung University Dongsan Medical Center. Nineteen patients whose total dose was below 30 Gy and one patient who underwent liver transplantation were excluded. The remaining 50 patients (45 males, 5 females; median age 55 years) were analyzed. According to the LCSGJ TNM stage, there were 27 patients (54.0%) with stage III and 23 (46.0%) with stage IV. Total dose of 30~54 Gy was administered (median 45). Thirty patients (60.0%) were treated with concurrent chemoradiation therapy (CCRT). The median follow-up duration was from 13.5 months (range, 3 to 70 months). Results: The median survival time from the start of RT was 9 months. One-year and 2-year overall survival rates were 24.9% and 11.2%, respectively. At the follow-up time, three patients (6.0%) displayed no evidence of disease. Seven patients (14.0%) were alive with disease, and 40 (80.0%) patients had expired due to disease progression. CCRT was associated with worse survival than RT alone (p=0.034), Response to RT (p=0.037), CLIP stage (p=0.017), and TNM stage (p=0.041) were statistically significant prognostic factors. There was no radiation-induced liver disease. Conclusion: RT is an effective and safe modality for HCC with PVTT. Further studies such as prospective randomized trials are needed to confirm the role of RT for HCC with PVTT.

• Food Science of Animal Resources
• /
• v.29 no.6
• /
• pp.709-718
• /
• 2009

The purpose of this study was to search for physical treatments to reduce allergenicity of pork. Physical treatments such as heating, autoclave, microwave, sonication, and irradiation have been used for food processing or reduction of allergenicity. The porcine serum albumin (PSA), known as a major allergen in pork, was extracted after physical treatments. The antigenicity of pork extracts by heating (80 and $100^{\circ}C$ for 20 min), autoclave ($121^{\circ}C$ for 5, 10, and 30 min), and microwave (for 5 and 10 min) was significantly decreased. Especially, the binding ability of p-IgG to pork extracts by autoclave for 30 min showed the greatest decrease (about 3%) in physical treatments. However, the antigenicity of pork was unaffected by sonication and irradiation treatment. These results indicated that the autoclave treatment was the most effective method to reduce the antigenicity of pork.

• Radiation Oncology Journal
• /
• v.24 no.4
• /
• pp.230-236
• /
• 2006

$\underline{Purpose}$: To analyze the response, toxicity, patterns of failure and survival rate of patients with locally advanced non-small cell lung cancer who were treated with concurrent chemoradiotherapy with weekly paclitaxel. $\underline{Materials\;and\;Methods}$: Twenty-three patients with locally advanced non-small cell lung cancer patients who received radical chemoradiotherapy from October 1999 to September 2004 were included in this retrospective study. Patients received total $55.4{\sim}64.8$ (median 64.8) Gy (daily 1.8 Gy per fraction, 5 days per weeks) over $7{\sim}8$ weeks. 50 or $60\;mg/m^2$ of paclitaxel was administered on day 1, 8, 15, 22, 29 and 36 of radiotherapy. Four weeks after the concurrent chemoradiotherapy, three cycles of consolidation chemotherapy consisted of paclitaxel $135\;mg/m^2$ and cisplatin $75\;mg/m^2$ was administered every 3 weeks. $\underline{Results}$: Of the 23 patients, 3 patients refused to receive the treatment during the concurrent chemoradiotherapy. One patient died of bacterial pneumonia during the concurrent chemoradiotherapy. Grade 2 radiation esophagitis was observed in 4 patients (17%). Sixteen patients received consolidation chemotherapy. During the consolidation chemotherapy, 8 patients (50%) experienced grade 3 or 4 neutropenia and one of those patients died of neutropenic sepsis. Overall response rate for 20 evaluable patients was 90% including 4 complete responses (20%) and 14 partial responses (70%). Among 18 responders, 9 had local failure, 3 had local and distant failure and 2 had distant failure only. Median progression-free survival time was 9.5 months and 2-year progression-free survival rate was 19%. Eleven patients received second-line or third-line chemotherapy after the treatment failure. The median overall survival time was 21 months. 2-year and 5-year survival rate were 43% and 33%, respectively. Age, performance status, tumor size were significant prognostic factors for progression-free survival. $\underline{Conclusion}$: Concurrent chemoradiotherapy with weekly paclitaxel revealed high response rate and low toxicity rate. But local failure occurred frequently after the remission and large tumor size was a poor prognostic factor. Further investigations are needed to improve the local control.

• Radiation Oncology Journal
• /
• v.17 no.1
• /
• pp.9-15
• /
• 1999

Purpose : This is a retrospective study to evaluate the response rate, acute toxicity, and survival rate of a combined chemotherapy and radiation therapy in limited disease small cell lung cancer, Materials and Methods : Firty-six patients with limited disease small-cell lung cancer who underwent combined chemotherapy and radiation therapy between October 1994 and April 1998 were evaluated. Six cycles of chemotherapy were planned either using a VIP regimen etoposide, ifosfamide, and cis-platin) or a EP regimen (etoposide and cis-platin). Thoracic radiation therapy was planned to deli- ver 44 Gy using 1 OMV X-ray, starting concurrently with chemotherapy. Response was evaluated 4 weeks after the completion of the planned chemotherapy and radiation therapy, and the prophylaetic cranial irradiation was planned only for the patients with complete responses. Acute toxicity was evaluated using the SWOG toxicity criteria, and the overall survival and disease-free survival were calculated using the Kaplan-Meier Method. Results : The median follow-up period was 16 months (range:2 to 41 months). Complete response was achieved En 30 (65$\%$) patients, of which 22 patients received prophylactic cranial irradiations. Acute toxicities over grade III were granulocytopenia in 23 (50$\%$), anemia in 17 (37$\%$), thrombo- cytopenia in nine (20$\%$), alopecia in nine (20$\%$), nausea/vomiting in five (11$\%$), and peripheral neuropathy in one (2$\%$). Chemotherapy was delayed in one patient, and the chemotherapy doses were reduced in 58 (24$\%$) out of the total 246 cycles. No radiation esophagitis over grade 111 was observed, while interruption during radiation therapy for a mean of 8.3 days occurred in 21 patients. The local recurrences were observed in 8 patients and local progressions were in 6 patients, and the distant metastases in 17 patients. Among these, four patients had both the local relapse and the distant metastasis. Brain was the most common metastatic site (10 patients), followed by the liver as the next common site (4 patients). The overall and progression-free survival rates were 79$\%$ and 55$\%$ in 1 year, and 45'/) and 32% in 2 years, respectively, and the median survival was 23 months. Conclusion : Relatively satisfactory local control and suwival rates were achieved after the combined chemotherapy and radiation therapy with mild to moderate acute morbidities in limited disease small cell lung cancer.

• Radiation Oncology Journal
• /
• v.22 no.3
• /
• pp.200-207
• /
• 2004

Purpose: An analysis was to compare the results of radiation alone with those of radiation with dally low dose cisplatin as a radiation sensitizer in locally advanced cervical cancer. Materials and Methods: A retrospective analysis of 59 patients diagnosed with locally advanced uterine cervix cancer between December 1996 and March 2001 was peformed. Thirty one patients received radiation alone and 28 patients received dally low dose cisplatin, as a radiation sensitizer, and radiation therapy. The median follow-up period was 34 months, ranging from 2.5 to 73 months. The radiation therapy consisted of 4500 cGy external beam irradiation to the whole pelvis (midline block after 3060 cGy), a 900$\~$l,000 cGy boost to the involved parametrium and high dose-rate intracavitary brachytherapy (a total dose of 3,000$\~$3,500 cGy/500 cGy per fraction to point A, twice per week). In the chemoradiation group, 10 mg of daily intravenous cisplatin was given daily from the 1st day of radiation therapy to the 20th day of radiation therapy. According to the FIGO classification, the patients were subdivided into 51 (86.4$\%$) and 8 (13.6$\%$) stages IIB and stage IIIB, respectively. Results: The overall 5 year survival rate was 65.65$\%$ and according to treatment modality were 56.75$\%$ and 73.42$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.180). The 5 year disease-free survival rates were 49.39$\%$ and 63.34$\%$ in the radiation alone and chemoradiatoin groups, respectively (p=0.053), The 5 year locoregional control rates were 52.34$\%$ and 73.58$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.013). The 5 year distant disease-free survival rates were 59.29$\%$ and 81.46$\%$ in the radiation alone and chemoradiation groups, respectively (p=0.477), Treatment related hematologic toxicity were prominent in the chemoradiation group. Leukopenia $\geq$grade) occurred in 3.2$\%$and 28.5$\%$ of the radiation alone and chemoradiation groups, respectively (p=0.02). There were no statistical differences in the incidences of vesical, rectal and small bowel complications between two groups. Conclusion: Radiation therapy with low dose cisplatin did not improve the rates of survival and response rates, but did improve the rate of disease free survival and locoregional control rates In locally advanced cervical cancer. The incidence of bone marrow suppression was higher in the chemoradiation group.

• Radiation Oncology Journal
• /
• v.26 no.4
• /
• pp.247-256
• /
• 2008

Purpose: The purpose of this study is to evaluate anal sphincter preservation rates, survival rates, and prognostic factors in patients with rectal cancer treated with preoperative chemoradiotherapy. Materials and Methods: One hundred fifty patients with pathologic confirmed rectal cancer and treated by preoperative chemoradiotherapy between January 1999 and June 2007. Of the 150 patients, the 82 who completed the scheduled chemoradiotherapy, received definitive surgery at our hospital, and did not have distant metastasis upon initial diagnosis were enrolled in this study. The radiation dose delivered to the whole pelvis ranged from 41.4 to 46.0 Gy (median 44.0 Gy) using daily fractions of $1.8{\sim}2.0\;Gy$ at 5 days per week and a boost dose to the primary tumor and high risk area up to a total of $43.2{\sim}54\;Gy$ (median 50.4 Gy). Sixty patients (80.5%) received 5-fluorouracil, leucovorin, and cisplatin, while 16 patients (19.5%) were administered 5-fluorouracil and leucovorin every 4 weeks concurrently during radiotherapy. Surgery was performed for 3 to 45 weeks (median 7 weeks) after completion of chemoradiotherapy. Results: The sphincter preservation rates for all patients were 73.2% (60/82). Of the 48 patients whose tumor was located at less than 5 cm away from the anal verge, 31 (64.6%) underwent sphincter-saving surgery. Moreover, of the 34 patients whose tumor was located at greater than or equal to 5 cm away from the anal verge, 29 (85.3%) were able to preserve their anal sphincter. A pathologic complete response was achieved in 14.6% (12/82) of all patients. The downstaging rates were 42.7% (35/82) for the T stage, 75.5% (37/49) for the N stage, and 67.1% (55/82) for the overall stages. The median follow-up period was 38 months (range $11{\sim}107$ months). The overall 5-year survival, disease-free survival, and locoregional control rates were 67.4%, 58.9% and 84.4%, respectively. The 5-year overall survival rates based on the pathologic stage were 100% for stage 0 (n=12), 59.1% for stage I (n=16), 78.6% for stage II (n=30), 36.9% for stage III (n=23), and one patient with pathologic stage IV was alive for 43 months (p=0.02). The 5-year disease-free survival rates were 77.8% for stage 0, 63.6% for stage I, 58.9% for stage II, 51.1% for stage III, and 0% for stage IV (p<0.001). The 5-year locoregional control rates were 88.9% for stage 0, 93.8% for stage I, 91.1% for stage II, 68.2% for stage III, and one patient with pathologic stage IV was alive without local recurrence (p=0.01). The results of a multivariate analysis with age (${\leq}55$ vs. >55), clinical stage (I+II vs. III), radiotherapy to surgery interval (${\leq}6$ weeks vs. >6 weeks), operation type (sphincter preservation vs. no preservation), pathologic T stage, pathologic N stage, pathologic overall stage (0 vs. I+II vs. III+IV), and pathologic response (complete vs. non-CR), only age and pathologic N stage were significant predictors of overall survival, pathologic overall stage for disease-free survival, and pathologic N stage for locoregional control rates, respectively. Recurrence was observed in 25 patients (local recurrence in 10 patients, distant metastasis in 13 patients, and both in 2 patients). Acute hematologic toxicity ($\geq$grade 3) during chemoradiotherapy was observed in 2 patients, while skin toxicity was observed in 1 patient. Complications developing within 60 days after surgery and required admission or surgical intervention, were observed in 11 patients: anastomotic leakage in 5 patients, pelvic abscess in 2 patients, and others in 4 patients. Conclusion: Preoperative chemoradiotherapy was an effective modality to achieve downstaging and sphincter preservation in rectal cancer cases with a relatively low toxicity. Pathologic N stage was a statistically significant prognostic factor for survival and locoregional control and so, more intensified postoperative adjuvant chemotherapy should be considered in these patients.