• The Journal of Korean Academy of Prosthodontics
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• v.57 no.2
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• pp.127-133
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• 2019

Purpose: The purpose of present study was to investigate fracture strength and mode of failure of endodontically treated teeth restored with metal cast post-core system, prefabricated fiber post system, and newly introduced polyetherketoneketone (PEKK) post-core system. Materials and methods: A total of 21 mandibular premolar were randomly grouped into 3 groups of 7 each according to the post material. Group A was for metal cast post core; Group B for prefabricated glass fiber post and resin core; and Group C for milled PEKK post cores. All specimens were restored with metal crown. The fracture strength of each specimen was measured by applying a static load of 135-degree to the tooth at 2 mm/min crosshead speed using a universal testing machine. After the fracture strength measurement, the mode of failure was observed. The results were analyzed using Kruscal-Wallis test and post hoc Mann-Whitney U test at confidence interval ${\alpha}=.05$. Results: Fracture resistance of PEKK post core was lower than those of cast metal post and fiber reinforced post with composite resin core. In the aspect of fracture mode most of the root fracture occurred in the metal post core, whereas the post detachment occurred mainly in the fiber reinforced post. In the case of PEKK post core, teeth and post were fractured together. Conclusion: It is necessary to select appropriate materials of post for extensively damaged teeth restoration and clinical application of the PEKK post seems to require more research on improvement of strength.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.253-260
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• 2003

Purpose: No general consensus has been reached regarding the necessity of postoperative radiation therapy (PORT) and the optimal techniques of its application for patients with chest wall invasion (pT3cw) and node negative (NO) non-small cell lung cancer (NSCLC). We retrospectively analyzed the PT3cwN0 NSCLC patients who received PORT because of presumed inadequate resection margin on surgical findings. Materials and Methods: From Aug. 1994 till June 2000, 21 pT3cwN0 NSCLC patients received PORT at Samsung Medical Center; all of whom underwent curative on-bloc resection of the primary tumor plus the chest wall and regional lymph node dissection. PORT was typically stalled 3 to 4 weeks after operation using 6 or 10 MV X-rays from a linear accelerator. The radiation target volume was confined to the tumor bed plus the immediate adjacent tissue, and no regional lymphatics were included. The planned radiation dose was 54 Gy by conventional fractionation schedule. The survival rates were calculated and the failure patterns analyzed. Results: Overall survival, disease-free survival, loco-regional recurrence-free survival, and distant metastases-free survival rates at 5 years were 38.8$\%$, 45.5$\%$, 90.2$\%$, and 48.1$\%$, respectively. Eleven patients experienced treatment failure: six with distant metastases, three with intra-thoracic failures, and two with combined distant and intra-thoracic failures. Among the five patients with intra-thoracic failures, two had pleural seeding, two had in-field local failures, and only one had regional lymphatic failure in the mediastinum. No patients suffered from acute and late radiation side effects of RTOG grade 3 or higher. Conclusion: The strategy of adding PORT to surgery to improve the probability, not only of local control but also of survival, was justified, considering that local control was the most important component in the successful treatment of pT3cw NSCLC patients, especially when the resection margin was not adequate. The incidence and the severity of the acute and late side effects of PORT were markedly reduced, which contributed to improving the patients' qualify of life both during and after PORT, without increasing the risk of regional failures by eliminating the regional lymphatics from the radiation target volume.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.16-22
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• 1999

Purpose : This study was done to analyze prognostic factors and patterns of failure of patients with histologically confirmed adenocarcinoma of the uterine cervix. Materials and Methods : From June 1988 to December 1990, a retrospective analysis was undertaken for 45 patients who were treated with curative radiation therapy for adenocarcinoma of the uterine cervix at the department of Therapeutic Radiology of Keimyung University Hospital. According to FIGO staging classification, f2 patients were stage Ib, 9 patients were lla, 19 patients were IIB, and 5 patients were lIIb. Median age of the patients was 54 years. The radiation therapy consisted of a combination of external and intracavitary irradiation. Only the pelvis was treated for external irradiation, but 6 patients were treated with extended field irradiation including paraaortic nodes. Intracavitary irradiation was performed with high dose rate sources (Co-60). Neoadiuvant chemotherapy was undertaken for 10 patients. Median and maximum follow-up duration was 64 and 116 months, respectively. Results : The overall 5-year survival rate was 55.2$\%$, and the 5-year survival rates for stage Ib, IIa, IIb, and IIIb were 100$\%$, 50.8$\%$, 46.8$\%$, and 40$\%$ (3-year survival rate), respectively. Of the many clinicopathologic variables evaluated for prognosis, only the stage and the tumor size were significant prognostic factors. Statistically, pelvic failure rates for stage Ib, IIa, IIb, and IIIb were 0$\%$, 33.3$\%$, 57.9$\%$, and 60$\%$, respectively. Distant metastasis rates were 0$\%$, 33.3$\%$, 21.1$\%$, and 40$\%$ for stage Ib, IIa, IIb, and IIIb, respectively. Especially the 6 patients who were irradiated with extended field to treat the paraaortic nodes were free of distant metastasis all. But, 9 patients (23.1$\%$) of the 39 patients who were not irradiated the paraaortic nodes were suffered and expired from uncontrolled distant metastasis. Conclusions : As compared with other studies, the survival rates were similar, but distant metastasis rates including paraaortic nodes metastasis were likely somewhat higher than expected, especially for patients with stage II. So, we think that the effect of prophylactic paraaortic nodes irradiation should be studied prospectively, especially for patients with pelvic nodes involvement or advanced stage of disease.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.126-132
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• 2009

Purpose: We wanted to evaluate the prognostic factors for the pathologic N2 non-small cell lung cancer (NSCLC) patients who were treated by postoperative radiotherapy. Materials and Methods: We retrospectively reviewed 112 pN2 NSCLC patients who underwent surgery and postoperative radiotherapy (PORT) From January 1999 to February 2008. Seventy-five (67%) patients received segmentectomy or lobectomy and 37 (33%) patients received pneumonectomy. The resection margin was negative in 94 patients, and it was positive or close in 18 patients. Chemotherapy was administered to 103 (92%) patients. Nine (8%) patients received PORT alone. The median radiation dose was 54 Gy (range, 45 to 66), and the fraction size was 1.8~2 Gy. Results: The 2-year overall survival (OS) rate was 60.2% and the disease free survival (DFS) rate was 44.7% for all the patients. Univariate analysis showed that the patients with multiple-station N2 disease had significantly reduced OS and DFS (p=0.047, p=0.007) and the patients with an advanced T stage ($\geq$T3) had significantly reduced OS and DFS (p<0.001, p=0.025). A large tumor size ($\geq$5 cm) and positive lymphovascular invasion reduced the OS (p=0.035, 0.034). Using multivariate analysis, we found that multiple-station N2 disease and an advanced T stage ($\geq$T3) significantly reduced the OS and DFS. Seventy one patients (63.4%) had recurrence of disease. The patterns of failure were loco-regional in 23 (20.5%) patients, distant failure in 62 (55.4%) and combined loco-regional and distant failure in 14 (12.5%) patients. Conclusion: Multiple involvement of mediastinal nodal stations for the pN2 NSCLC patients with PORT was a poor prognostic factor in this study. A prospective study is necessary to evaluate the N2 subclassification and to optimize the adjuvant treatment.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.41-48
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• 1995

Purpose : The adjuvant postoperative radiotherapy has been usually applied to the patients with unfavorable prognostic factors after radical operation in early cervical cancer. We focused on the evaluation of the survival status and failure patterns of the patients with postoperative radiotherapy. Materials and Methods : We retrospectively analyzed ninety patients with FIGO stage IB and IIA cervix cancer who received postoperative pelvic irradiation at Chonnam University Hospital between August 1985 and December 1988, Seventy-eight patients had adequate follow-up information for survival analysis. Median follow-up time of these patients was 64 months. Results : The 5 year overall and disease free survival rate of ninety patients was $80.0\%$ and $80.2\%$, respectively. The prognostic significance to the survival was determined by multivariate analysis. Adequacy of resection margin(p=0.005) and lymph node status(p=0.005) appeared to be independent prognostic factors. Recurrence occurred in 13 patients, 5 in the pelvis and 8 at distant sites. The median time to recurrence was 19 months(range:3-39 months). The pelvic recurrence was more prevalent in the group of patients with adenocarcinoma, depth of stromal invasion more than 10mm and use of chemotherapy. The distant failure was more prevalent in the group of positive resection margin or positive lymph node with statistical significance. Conclusion : Patients with pelvic lymph node or surgical margin involvement clearly constitute a high risk group in this analysis and should be considered as candidates for some form of adjuvant therapy.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.125-132
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• 2010

Purpose: To retrospectively assess the advantages and side effects of prophylactic Paraaortic irradiation in cervical cancer patients with common iliac nodal involvement, the results for survival, patterns of failure, and treatment-related toxicity. Materials and Methods: From May 1985 to October 2004, 909 patients with cervical carcinoma received postoperative radiotherapy at the Seoul National University Hospital. Among them, 54 patients with positive common iliac nodes on pathology and negative Paraaortic node were included in the study. In addition, 44 patients received standard pelvic irradiation delivered 50.4 Gy per 28 fractions (standard irradiation group), and chemotherapy was combined in 16 of them. The other 10 patients received pelvic irradiation at a dose of 50.4 Gy per 28 fractions in addition to Paraaortic irradiation at 45 Gy per 25 fractions (extended irradiation group). In addition, all of them received chemotherapy in combination with radiation. Follow-up times for pelvic and Paraaortic irradiation ranged from 6 to 201 months (median follow-up time, 58 months) and 21 to 58 months (median follow-up time, 47 months), respectively. Results: The 4-year overall survival, disease free survival, and distant metastasis free survival in the standard irradiation group and extended irradiation group were 67.2% vs. 90.0% (p=0.291), 59.0% vs. 70.0% (p=0.568) and 67.5% vs. 90.0% (p=0.196), respectively. The most common site of first failure for the standard irradiation group was the paraaortic lymph node, while no paraaortic failure was observed in the extended irradiation group. Relatively, hematologic toxicity grade 3 or greater was common in the extended irradiation group (2/10 extended vs. 2/44 standard), while gastrointestinal toxicity of grade 3 or greater was lower (2/10 extended vs. 6/44 standard), and urologic toxicity of grade 3 or greater was observed in the standard irradition group only (0/10 vs. 3/44). Conclusion: Concurrent chemotherapy and prophylactic Paraaortic irradiation in patients with common iliac nodal involvement showed slightly improved clinical outcomes aside from increased hematologic toxicity, which was statistically insignificant. Considering the relatively small number of patients and short follow-up times, additional studies are needed to obtain more conclusive outcomes.

• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.72-81
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• 1994

Total 55 patients with nonsmall cell lung cancer treated with radiation therapy at Department of Therapeutic Radiology, Yeungnam University Hospital, between May-1 1986 and April-30 1993 were retrospectively analyzed by clinical characteristics, failure patterns, follow up duration and survival ratio according to prognostic factors. Obtained results were as follows : 1. Male to female ratio was 17.3 2. Sixth and seventh decades were predominant age group. 3. The patients were 8 in stage I-II, 34 in stage IIIA, 13 in stage IIIb, respectively. 4. Forty five patients out of 55 were squamous cell carcinoma. 5. Primary tumor were originated from upper lobe bronchi predominantly. 6. The size of the primary tumor, lymph node involvement and the degree of differentiation were important in evaluation of prognosis. 7. In conclusion, for patients with poor prognostic factors systemic chemotherapy and multidisciplinary approach were recommended for better treatment outcome and improvement of survival.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.538-553
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• 1999

The purpose of this study was to compare the shear bond strength and the anticariogenicity of glass ionomer cement with conventional bonding resin and fluoride releasing resin. After the shear bond strength test, scanning electron microscopic observation was performed for the evaluation of the fracture patterns in each group. Under the polarizing light microscope, artificially induced carious lesions were evaluated and the lesion depths of the samples were measured using image analyzing program(Image-Pro $PLUS^{TM}$, USA). 50 sound maxillary premolars were used for the bond strength test and another 30 for the anticariogenic test. Data collected were analyzed statistically using Oneway-ANOVA and Scheffe test. The results were as follows: 1. Glass ionomer groups(G-III, IV, V) generally showed the lower bond strength values than resin groups(G-I, II). 2. Among the two resin groups, G-I showed the higher bond strength than G-II without statistically significant difference between them(p>.05). 3. Within glass ionomer groups, statistical significance was found between G-III and G-V with the superior bond strength in G-V (p<.05). 4. Under the SEM, adhesive failure was the predominant fracture pattern in G-I and II, whereas cohesive failures were mainly observed in G-III. In G-IV and V, mixed type of pattern where the both fracture patterns coexisted within samples could be seen. 5. In evaluation of the depth of artificially developed carious lesion, glass ionomer group showed shallower depth than resin groups with statistical significance between G-III and G-I, II(p<.05). Among resin groups, fluoride releasing resin(G-II) showed the shallower depth than conventional resin(G-I)(p<.05).

• Radiation Oncology Journal
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• v.25 no.1
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• pp.16-25
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• 2007

[ $\underline{Purpose}$ ]: Breast conserving surgery (BCS) followed by chemotherapy (CTx.) and radiation therapy (RT) is widely performed for the treatment of early breast cancer. This retrospective study was undertaken to evaluate our interim results in terms of failure patterns, survival and relative risk factors. $\underline{Materials\;and\;Methods}$: From January 1999 through December 2003, 129 patients diagnosed with invasive breast cancer and treated with BCS followed by RT were subject to retrospective review. The median age of the patients was 45 years (age distribution, $27{\sim}76$ years). The proportions of patients according to their tumor, nodes, and metastases (TNM) stage were 65 (50.4%) in stage I, 41 (31.7%) in stage IIa, 13 (10.1%) in stage IIb, 9 (7.0%) in stage III, and 1 patient (0.8%) in stage IIIc. For 32 patients (24.8%), axillary node metastasis was found after dissection. BCS consisted of quadrantectomy in 115 patients (89.1%) and lumpectomy in 14 patients (10.6%). Axillary node dissection at axillary level I and II was performed for 120 patients (93%). For 7 patients (5.4%), only sentinel node dissection was performed with BCS. For 2 patients (1.6%) axillary dissection of any type was not performed. Postoperative RT was given with 6 MV X-rays. A tumor dose of 50.4 Gy was delivered to the entire breast area using a tangential field with a wedge compensator. An aditional dose of $9{\sim}16\;Gy$ was given to the primary tumor bed areas with electron beams. In 30 patients (23.3%), RT was delivered to the supraclavicular node. Most patients had adjuvant CTx. with $4{\sim}6$ cycles of CMF (cyclophosphamide, methotrexate, 5-fluorouracil) regimens. The median follow-up period was 50 months (range: $17{\sim}93$ months). $\underline{Results}$: The actuarial 5 year survival rate (5Y-OSR) was 96.9%, and the 5 year disease free survival rate (5Y-DFSR) was 93.7%. Local recurrences were noted in 2 patients (true: 2, regional node: 1) as the first sign of recurrence at a mean time of 29.3 months after surgery. Five patients developed distant metastases as the first sign of recurrence at $6{\sim}33$ months (mean 21 months). Sites of distant metastatic sites were bone in 3 patients, liver in 1 patient and systemic lesions in 1 patient. Among the patients with distant metastatic sites, two patients died at 17 and 25 months during the follow-up period. According to stage, the 5Y-OSR was 95.5%, 100%, 84.6%, and 100% for stage I, IIa, IIb, and III respectively. The 5Y-DFSR was 96.8%, 92.7%, 76.9%, and 100% for stage I, IIa, IIb, and III respectively. Stage was the only risk factor for local recurrence based on univariate analysis. Ten stage III patients included in this analysis had a primary tumor size of less than 3 cm and had more than 4 axillary lymph node metastases. The 10 stage III patients received not only breast RT but also received posterior axillary boost RT to the supraclavicular node. During the median 53.3 months follow-up period, no any local or distant failure was found. Complications were asymptomatic radiation pneumonitis in 10 patients, symptomatic pneumonitis in 1 patient and lymphedema in 8 patients. $\underline{Conclusion}$: Although our follow up period is short, we had excellent local control and survival results and reaffirmed that BCS followed by RT and CTx. appears to be an adequate treatment method. These results also provide evidence that distant failure occurs earlier and more frequent as compared with local failure. Further studies and a longer follow-up period are needed to assess the effectiveness of BCS followed by RT for the patients with less than a 3 cm primary tumor and more than 4 axillary node metastases.

• Radiation Oncology Journal
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• v.27 no.4
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• pp.181-188
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• 2009

Purpose: The aim of this study was to evaluate the results of postoperative radiotherapy in a case of perihilar cholagiocarcinoma by analyzing overall survival rate, patterns of failure, prognostic factors for overall survival, and toxicity. Materials and Methods: Between January 1998 and March 2008, 38 patients with perihilar cholangiocarcinoma underwent a surgical resection and adjuvant radiotherapy. The median patient age was 59 years (range, 28 to 72 years), which included 23 men and 15 women. The extent of surgery was complete resection in 9 patients, microscopically positive margins in 25 patients, and a subtotal resection in 4 patients. The tumor bed and regional lymphatics initially received 45 Gy or 50 Gy, but was subsequently boosted to a total dose of 59.4 Gy or 60 Gy in incompletely resected patients. The median radiotherapy dose was 59.4 Gy. Concurrent chemotherapy was administered in 30 patients. The median follow-up period was 14 months (range, 6 to 45 months). Results: The 3-year overall survival and 3-year progression free survival rates were 30% and 8%, respectively. The median survival time was 28 months. A multivariate analysis showed that differentiation was the only significant factor for overall survival. The 3-year overall survival was 34% in R0 patients and 20% in R1 patients. No statistically significant differences in survival were found between the 2 groups (p=0.3067). The first site of failure was local in 18 patients (47%). No patient experienced grade 3 or higher acute toxicity and duodenal bleeding developed in 2 patients. Conclusion: Our results suggest that adjuvant RT might be a significant factor in patients with a positive margin following a radical resection. However, there was still a high locoregional recurrence rate following surgery and postoperative radiotherapy. Further study is necessary to enhance the effect of the adjuvant radiotherapy.