• Radiation Oncology Journal
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• v.23 no.2
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• pp.71-77
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• 2005

Purpose: This retrospective study was conduced to analyze the treatment results and to evaluate the prognostic factors affecting the survival of nasopharyngeal carcinoma patients. Materials and Methods: From 1987 to 2002, we analyzed 43 patients who had nasopharyngeal carcinomas that were histologically confirmed and who had also completed the planned radiation therapy course at Keimyung University Dongsan Medical Center According to the 6th edition of American Joint Committee on Cancer staging system, 12 patients ($27.9\%$) were at Stage 11, 13 ($30.2\%$) were at Stage III and 18 ($41.9\%$) were at Stage IV Histopathologically, there were 15 ($34.9\%$) squamous cell carcinomas, 8 ($18.5\%$) nonkeratinizing carcinomas, 17 ($39.5\%$) undifferentiated carcinomas, and 3 ($7.0\%$) lymphoepitheliomas. Among the total 43 patients, 31 patients ($72.1\%$) were treated with only radiation therapy. Neoadjuvant chemotherapy was peformed on 7 patients ($16.3\%$) and concurrent chemoradiotherapy was performed on S patients ($11.6\%$). Cisplatin and 5-Fluorouracil were administered to 11 patients for 4 cycles, and Cisplatin and Taxotere were administered to 1 patient for 6 cycles. The range of the total radiation dose delivered to the primary tumor was from 61.2 to 84 Gy (median 70.4 Gy), The follow-up period ranged from 2 to 197 months with median follow-up of 84 months. Results: The local control rate at 6 months after radiation therapy was $90.7\%$. The five year overall survival and disease free survival rates were $50.7\%$ and $48.9\%$, respectively. On the multivariate analysis, the age, T-stage ($T_{1-3}\;vs\;T_4$), N-stage and AJCC stage were the statistically significant prognostic factors affecting survival (p<0.05). The patterns of failure were as follows: local failure only in 3 patients ($7.0\%$), local and systemic failure in 1 patient ($2.3\%$), and distant metastasis only in 11 patients ($25.6\%$). Conclusion: The prognostic factors affecting the outcome of nasopharyngeal carcinoma were age, T-stage (7$T_{1-3}\;vs\;T_4$), N-stage and stage. Because systemic metastasis was the main failure pattern noted for nasopharyngeal carcinoma, systemic chemotherapy is needed to decrease the rate of distant metastasis for nasopharyngeal carcinoma. In audition, research for more effective chemotherapeutical regimens and schedules is also needed.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.230-236
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• 2001

Purpose : To evaluate treatment results in terms of local control, complications and survival after reirraidiation in recurrent cervical cancer following definite radiation therapy. Material and methods : From November 1987 through March 1998, eighteen patients with recurrent cervical cancer following definite radiation therapy were subsequently treated with reirradiation at Keimyung University Dongsan Medical Center. In regard to the initial FIGO stage, one patient was stage la, five were stage IIa, three were IIb, two were IIb and two were IVa. The age range was 37 to 79 years old with median age of 57. The time interval from initial definite radiation therapy to recurrence ranged from 6 to 122 months with a median of 58 months. The recurrent sites were the uterine cervix in seven patients, vagina in ten and pelvic lymph node in one. Reirradiation was peformed with external radiation and intracavitary radiation in twelve patients, external radiation and implantation in four and external radiation alone in two. The range of external radiation dose was $2,100\~5,400\;cGy$ and the range of the total radiation dose was $3,780\~8,550\;cGy$. The follow-up periods ranged from 8 to 20 months with median of 25 following reirradiation. Results : Fourteen of eighteen patients $(78\%)$ had local control just after reirradiation. The two year disease free survival (2YDFS) rate was $53.6\%$. There were statistically significant differences in the 2YDFS according to both recurrent site (2YDFS $28.5\%$ in uterine cervix, $71.4\%$ in vagina, (p=0.03)) and the total dose (2YDFS $71.8\%$ in >6,000 cGy , $25\%$ in $\leq6,000$ cGy, p=0.007). Seven of ten patients who were followed for more than 20 months remain alive and disease free (7/18, $39\%$). Patients treated with external radiation and intracavitary radiation had a higher rate of 2YDFS. Seven patients including 4 patients with no local control experienced local failure in the uterus or vagina and two patients died with distant metastasis. Complications included rectal bleeding in 3 patients, bowel obstruction treated with surgery in two, hematuria in one, radiation cystitis in two, soft tissue swelling in two and vaginal necrosis spontaneously healed in one. There was no statistical difference in complications according to the total dose or the time to recurrence from initial radiation. Conclusion : In patients with recurrence following definite radiation therapy in the uterine cervical cancer, reirradiation may be effective but requires an effort to reduce radiation induced severe complications.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.206-214
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• 2002

Purpose : The aim of this study was to assess the effectiveness, survival rate and complications of radiation therapy and chemoradiation treatment in hypopharyngeal cancer. Methods and Materials : From January 1984 to December 1999, 56 patients who had hypopharyngeal carcinoma treated with curative radiation therapy were retrospectively studied. Twenty four patients $(42.9\%)$ were treated with radiation therapy alone (Group I) and $32\;(57.1\%)$ treated with a combination of chemotherapy and radiation (Group II). Total radiation dose ranged from 40.5 to 83. 5 Gy (median 67.9 Gy). Radiotherapy was given with conventional technique in 9 patients $(16.4\%)$, with hyperfractionation I ($1.15\~1.2$ Gy/fr., BID) in 26 $(47.2\%)$, hyperfractionation II (1.35 Gy/fr., BID) in 18 $(32.7\%)$, and accelerated fractionation (1.6 Gy/fr., BID) in 2 $(3.6\%)$. In chemotherapy, 5-FU ($1,000\;mg/m^2$ daily for 5 consecutive days) and cisplatin ($100\;mg/m^2$ on day 1) were administered in a cycle of 3 weeks interval, and a total of 1 to 3 cycles (average 2..3 cycles) were given prior to radiation therapy. Follow up duration was $1\~195$ months (median 28 months). Results : Overall 2 and 5 year survival rates were $40.6\%\;and\;27.6\%;\;50.0\%\;and\;30.0\%$ in Group I, and $36.4\%\;and\;26.3\%$ in Group II, respectively. Complete local control rates in Group I and II were $70.0\%\;and\;67.7\%$, respectively. The response to radiotherapy and nodal stage were statistically significant prognostic factors. The complication rate was increased in Group II and was decreased in hyperfractionation. Conclusion : The response to radiotherapy and nodal stage were valid factors to indicate the degree of control over the hypopharyngeal cancer. The induction cisplatin, 5-Fu chemotherapy was not valid in terms of local control rate and survival rate, but did contribute to an increased complication rate. The use of hyperfractionation was valid to reduce the late radiation complications.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.215-220
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• 2002

Purpose : Preoperative radiotherapy has been used to induce tumor regression and allow complete resection of rectal cancer with a sphincter preservation surgery. This study was performed to determine the effectiveness of preoperative radiotherapy for $T_2,\;T_3$ distal rectal carcinoma. Materials and Methods : From November 1995 to June 1997, fifteen patients with invasive distal rectal cancer were treated with preoperative radiotherapy followed by sphincter preservation surgery. Classification by preoperative T stage consisted of 7 $T_2$ and 8 $T_3$ tumors. Radiation therapy was delivered with 6 MV and 15 MV linear accelerator, at 1.8 Gy fractions for 5 days per week. Total radiation doses were 45 Gy to 50.4 Gy (median : 50.4 Gy). Sphincter preservation surgery was peformed $4\~6$ weeks after the completion of radiotherapy. Median follow-up was 22 months (range : $16\~37\;months$). Results : One patient $(6.7\%)$ had a complete pathologic response. Comparing the stage at the diagnostic workup with the pathologic stage, tumor downstaging of T stages occurred in 11 of 15 patients $(73.3\%)$ and $N_1$ stages occurred in 2 of 5 patients $(40\%)$. No patient developed progressive disease undergoing treatment. Two patients suffered local recurrence at 7 and 20 months, and one a distant metastasis at 30 months. No grade 3 or 4 toxicity was observed. Conclusion : Our experience suggests that preoperative radiotherapy followed by sphincter preservation surgery is well tolerated, and can significantly reduce the tumor burden for $T_2\;T_3$ distal rectal cancer.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.318-330
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• 2009

A high heat flux test facility using a graphite heating panel was constructed and is presently in operation at Korea Atomic Energy Research Institute, which is called KoHLT-1. Its major purpose is to carry out a thermal cycle test to verify the integrity of a HIP (hot isostatic pressing) bonded Be mockups which were fabricated for developing HIP joining technology to bond different metals, i.e., Be-to-CuCrZr and CuCrZr-to-SS316L, for the ITER (International Thermonuclear Experimental Reactor) first wall. The KoHLT-1 consists of a graphite heating panel, a box-type test chamber with water-cooling jackets, an electrical DC power supply, a water-cooling system, an evacuation system, an He gas system, and some diagnostics, which are equipped in an authorized laboratory with a special ventilation system for the Be treatment. The graphite heater is placed between two mockups, and the gap distance between the heater and the mockup is adjusted to $2{\sim}3\;mm$. We designed and fabricated several graphite heating panels to have various heating areas depending on the tested mockups, and to have the electrical resistances of $0.2{\sim}0.5$ ohms during high temperature operation. The heater is connected to an electrical DC power supply of 100 V/400 A. The heat flux is easily controlled by the pre-programmed control system which consists of a personal computer and a multi function module. The heat fluxes on the two mockups are deduced from the flow rate and the coolant inlet/out temperatures by a calorimetric method. We have carried out the thermal cycle tests of various Be mockups, and the reliability of the KoHLT-1 for long time operation at a high heat flux was verified, and its broad applicability is promising.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.347-356
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• 2013

To provide the information for the wetland management considering the water treatment ability of macrophytes, the growth characteristics and primary production by reed (Phragmites australis) and cattail (Typha angustifolia), and the decomposition rate of organic matter produced were investigated in two sub-wetlands (Banweol and Donhwa wetlands) of the Sihwa Constructed Wetland (CW) with different chemistry of inflows. The shoot height of P. australis and Typha angustifolia began to increase in March, and reached its peaks in July and August (340cm and 320cm, respectively). The shoot density of P. australis ranging $100{\sim}170EA/m^2$ was higher than that of T. angustifolia (max. $78EA/m^2$). Standing biomass of P. australis ranged from $1,350{\sim}1,980gDM/m^2$, with maximal biomass in Banwol Upper Wetland. And it was larger in upper wetlands than lower wetlands. On the other hand standing biomass of T. angustifolia ($1,940gDM/m^2$) was similar to that of P. australis in Banwol Upper Wetland. Primary productivity of P. australis was in the order of Banwol Upper Wetland ($2,050gDM/m^2/yr$) > Donghwa Lower Wetland ($1,840gDM/m^2/yr$) > Banwol Lowerr Wetland ($1,570gDM/m^2/yr$) ${\fallingdotseq}$ Donghwa Lower Wetland ($1,540gDM/m^2/yr$), and that of T. angustifolia ($2,210gDM/m^2/yr$) was higher than P. australis. Annual production of organic matter produced by P. australis and T. angustifolia was 845 ton DM/yr (423 ton C/yr), and about 90% was comprised of that by P. australis. From the litter decomposition rate (k) (P. australis: leaf 0.0062/day, stem 0.0018/day; T. angustifolia: leaf 0.0031/day, stem 0.0018/day), leaf was rapid degraded compare to stem in both P. australis and T. angustifolia. The litter decomposition rate of leaf was two times rapid P. australis than T. angustifolia, whereas that of stem was same in both. Annual litter decomposition amount of P. australis than T. angustifolia was 285 ton C/yr(67.3% of organic matter produced by macrophytes), indicating that 32.7% of organic matter produced by macrophytes is accumulated in the Sihwa CW.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.63-69
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• 1998

Purpose : This study is to evaluate the efficacy of small bowel displacement system(SBDS) in post-operative pelvic radiation therapy(RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. Materials and Method : Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink $Castrographin^(R)$ before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using Picture archiving and communication system (PACS). Results : The average small bowel volumes with and without SBDS were 176.0ml(5.2-415.6ml) and 185.1ml(54.5-434.2ml), respectively The changes of small bowel volume with SBDS compared to those without SBDS were more than $10\%$ decrease in three, less than 10% decrease in two, less than $10\%$ increase in three, and more than $10\%$ increase in two patients. Conclusion : No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.447-454
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• 1998

Purpose : This study evaluated the survival, local control, prognostic factor, and failure pattern of patients with esophageal cancer treated with operation and adjuvant radiation therapy to use as fundermental data of postoperative radiation therapy. Materials and Methods : A retrospective analysis was undertaken of 82 patients who had locally advanced esophageal cancer treated with operation and adjuvant radiation therapy from January 1988 to December 1995. According to AJCC staging, stage IIA were in 26 patients, stage IIB in 4 patients, and stage III in 52 patients. Squamous cell carcinoma were in 77 patients, adenosquamous carcinoma in 3 patients, and adenocarcinoma in 2 patients. The patients received radiation therapy ranging from 41.0 Gy to 64.8 Gy. Five patients received neoadjuvant chemotherapy. Results : Two-year survival and local control rates for all patients were 36.8$\%$ and 30.4$\%$ respectively. And they were 9.3$\%$ and 26.3$\%$ respectively at 5 years. According to stages, 2-year survival rates were 50.2$\%$ in IIA, 0$\%$ in IIB and 23.3$\%$ in III (p=0.004). Two-year local control rates were 49.2 $\%$ in IIA, 66.6$\%$ in IIB and 24.7$\%$ in III (p=0.01). Sixty patients developed recurrence, which were 3 tumor margin, 23 lymph node recurrence, 4 tumor margin and lymph node, 1 tumor margin and distant metastasis, 9 lymph node and distant metastasis, 17 distant metastasis and 3 unknown metastatic site. Prognostic factors affecting survival were smoking (p=0.02), T-staging (p=0.0092), N-staging (p=0.0045). Prognostic factors affecting local control were T-staging (p=0.019), N-staging (p=0.047). Conclusion : In spite of post-operative radiation therapy, predominant failure pattern was local failure. Especially regional lymph node failure was major cause of local failure. So strategy of aggresive adjuvant radiation therapy to regional lymph node area in post operative treatment should be proposed.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.288-297
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• 2004

Puporse: The aims of this study were to evaluate the change of $[^18F]fluoromisonidazole$($[^18F]FMISO$) uptake in C3H mouse squamous cell carcinoma-VII (SCC-VII) treated with mild hyperthermia ($42^{circ}C$) and nicotinamide and to assess the biodistribution of the markers in normal tissues under similar conditions. Methods and Materials: $[^18F]FMISO$ was producedby our hospital. Female C3H mice with a C3H SCC-VII tumor grown on their extremities were used. Tumors were size matched. Non-anaesthetized, tumor-bearing mice underwent control or mild hyperthermia at $42^{circ}C$ for 60 min with nicotinamide (50 mg/kg i.p. injected) and were examined by gamma counter, autoradiography and animal PET scan 3 hours after tracer i.v. injected with breathing room air, The biodistribution of these agents were obtained at 3 h after $[^18F]FMISO$ injection. Blood, tumor, muscle, heart, lung, liver, kidney, brain, bone, spleen, and intestine were removed, counted for radioactivity and weighed. The tumor and liver were frozen and cut with a cryomicrotome into 10- um sections. The spatial distribution of radioactivity from the tissue sections was determined with digital autoradiography. Results: The mild hyperthermia with nicotinamide treatment had only slight effects on the biodistribution of either marker in normal tissues. We observed that the whole tumor radioactivity uptake ratios were higher in the control mice than in the mild hyperthermia with nicotinamide treated mice for $[^18F]FMISO$ ($1.56{\pm}1.03$ vs. $0.67{\pm}0.30$; p=0.063). In addition, autoradiography and animal PET scan demonstrated that the area and intensity of $[^18F]FMISO$ uptake was significantly decreased. Conclusion: Mild hyperthermla and nicotinamide significantly improved tumor hypoxia using $[^18F]FMISO$ and this uptake reflected tumor hypoxic status.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.265-270
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• 2004

Purpose: To evaluate the effectiveness of postoperative radiation therapy in cervical cancer patients and define the prognostic factors to affect survival rates. Materials and Methods: Eighty one patients with cervical cancer who were treated with postoperative radiation therapy following surgery at our institution between May 1992 and April 2000 were retrospectivelv analyzed. Forty two patients had stage IB disease, 17 had stage IIA disease, and remaining 22 had stage IIB disease, respectively. Histological examination revealed 76 squamous cell carcinoma and 5 adenocarclnoma. Sixty one patients were noted to have stromal invasion greater than 8 mm and 20 patients were noted to have stromal invasion 7 mm or less. Sixteen patients had parametrial invasion and 65 patients did not. Positive vaginal resection margin was documented in only eight patients and positive lymphovascular invasion was in twelve patients. All of the patients were treated with external beam radiation therapy alone. Majority of the patients were treated with 4 field brick technique to encompass whole pelvis. Total of 5,500 cGy was delivered to the primary surgical tumor bed. Minimum follow up period was four years. Results: Actuarial disease free survival rates for entire group of the patients were 95% and 89% at 2 and 5 years, respectively Five year disease free survival rates for patients with stage IB, IIA, and IIB disease were 97%, 87% and 70%, respectivelv. Local recurrences were documented in 5 patients. Cumulative local failure rate at 3 years was 6% Five year disease free survival rates for patients with stromal invasion greater than 8 mm and 7 mm or less were 88% and 92%, respectively (p>0.05). Five year disease free survival rate for patients with parametrial invasion was significantly lower than those with no invasion (72% vs 92%, p<0.05). Also there was significantly lower survival in patients with positive vaginal resection margin, compared with patients with negative resection margin (64% vs 94%, p<0.05). However, lymphovascular invasion was not a statistically significant prognostic factor Parametrial invasion and positive surgical resection margins were noted to be significant prognostic factors. Conclusions: Postoperative radiation therapy appears to be beneficial in controlling local disease in cervical cancer patients with high pathologic risk factors. Parametrial invasion and positive resection margins were noted to be significant prognostic factors to affect survival and more effective treatment should be investigated in these patients.