1.Surgery Alone or Postoperative Adjuvant Radiotherapy in Rectal Cancer: With Respect to Survival, Pelvic Control, Prognostic Factor.
Taek Keun NAM ; Sung Ja AHN ; Byung Sik NAH
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2001;19(4):327-334
PURPOSE: To find out the role of postoperative adjuvant radiotherapy in the treatment of rectal cancer by comparing survival, pelvic control, complication rate, and any prognostic factor between surgery alone and postoperative radiotherapy group. MATERIALS AND METHODS: From Feb. 1982 to Dec. 1996 total 212 patients were treated by radical surgery with or without postoperative radiotherapy due to rectal carcinoma of modified Astler-Coller stage B2-C3. Of them, 18 patients had incomplete radiotherapy and so the remaining 194 patients were the database analyzed in this study. One hundred four patients received postoperative radiotherapy and the other 90 patients had surgery only. Radiotherapy was performed in the range of 39.6-55.8 Gy (mean: 49.9 Gy) to the whole pelvis and if necessary, tumor bed was boosted by 5.4-10 Gy. Both survival and pelvic control rates were calculated by Kaplan-Meier method and their statistical significance was tested by Log-rank test. Multivariate analysis was performed by Cox proportional hazards model. RESULTS: 5-year actuarial survival rate (5YSR) and 5-year disease-free survival rate (5YDFSR) of entire patients were 53% and 49%, respectively. 5YSRs of surgery alone group and adjuvant radiotherapy group were 63% vs 45%, respectively ( p=0.03). This difference is thought to reflect uneven distribution of stages between two treatment groups ( p<0.05 by x2-test) with more advanced disease patients in adjuvant radiotherapy group. 5YSRs of surgery alone vs adjuvant radiotherapy group in MAC B2+3, C1, C2+3 were 68% vs 55% ( p=0.09), 100% vs 100%, 40% vs 33% ( p=0.71), respectively. 5YDFSRs of surgery alone vs adjuvant radiotherapy group in above three stages were 65% vs 49% ( p=0.14), 100% vs 100%, 33% vs 31% ( p=0.46), respectively. 5-year pelvic control rate (5YPCR) of entire patients was 72.5%. 5YPCRs of surgery alone and adjuvant radiotherapy group were 71% vs 74%, respectively (p=0.41). 5YPCRs of surgery alone vs adjuvant radiotherapy group in B2+3, C1, C2+3 were 79% vs 75% ( p= 0.88), 100% vs 100%, 44% vs 68% ( p=0.01), respectively. Multivariate analysis showed that only stage was significant factor affecting overall and disease-free survival in entire patients and also in both treatment groups. In view of pelvic control, stage and operation type were significant in entire patients and only stage in surgery alone group but in adjuvant radiotherapy group, operation type instead of stage was the only significant factor in multivariate analysis as a negative prognostic factor in abdominoperineal resection cases. CONCLUSION: Our retrospective study showed that postoperative adjuvant radiotherapy could improve the pelvic control in MAC C2+3 group. To improve both pelvic control and survival in all patients with MAC B2 or more, other treatment modality such as concurrent continuous infusion of 5-FU, which is the most standard agent, along with radiotherapy should be considered.
Disease-Free Survival
;
Fluorouracil
;
Humans
;
Multivariate Analysis
;
Pelvis
;
Proportional Hazards Models
;
Radiotherapy
;
Radiotherapy, Adjuvant*
;
Rectal Neoplasms*
;
Retrospective Studies
;
Survival Rate
2.External Beam Radiotherapy Alone in Advanced Esophageal Cancer.
Sung Ja AHN ; Woong Ki CHUNG ; Byung Sik NAH ; Taek Keun NAM
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2000;18(1):11-16
PURPOSE: We performed the retrospective analysis to find the outcome of external beam radiotherapy alone in advanced esophageal cancer patients. METHODS AND MATERIALS: One hundred and six patients treated with external beam radiotherapy alone between July 1990 and December 1996 were analyzed retrospectively. We limited the site of the lesions to the thoracic esophagus and cell type to the squamous cell carcinoma. Follow-up was completed in 100 patients (9 4%) and ranged from 1 month to 92 months (median; 6 months). RESULTS: The median age was 62 years old and male to female ratio was 104:2. Fifty-three percent was the middle thorax lesion and curative radiotherapy was performed in 83%. Mean tumor dose delivered with curative aim was 58.6 Gy (55-70.8 Gy) and median duration o f the radiation therapy was 53 days. The median survival of all patients was 6 months and 1-year and 2-year overall survival rte was 27% and 12%, respectively. Improvement of dysphagia was obtained in most patients except fo 7 patients who underwent feeding gastrostomy. The complete response rate immediately after radiation therapy was 32% (34/106). The median survival and 2-year survival rate of the complete responder was 14 months and 30% respectively, while those of the nonresponder was 4 months and 0% respectively (p=0.000). The median survival and 2-year survival rate of the patients who could tolerate regular diet was 9 rnonths and 16% while those of the patients who could not tolerate regular diet was 3 months and 0%, respectively (p=0.004). The survival difference between the patients with 5 cm or less turnor length and those with more than 5 cm tumor length was rnarginally statistically significant (p=0.06). However, the survival difference according to the periesophageal invasion or mediastinal lymphadenopathy in the chest CT imaging study was not statistically significant in this study. In a multivariate analysis, the statistically significant covariates to the survival were complete response to radiotherapy, tumor length, and initial degree of dysphagia in a decreasing order. The complication was observed in 10 patients (9%). CONCLUSION: The survival outcome for advanced esophageal cancer patients treated by external be am radiotherapy alone was very poor, In the treatment of these patients, the brachytherapy and chemotherapy should be added to improve the treatment outcome.
Brachytherapy
;
Carcinoma, Squamous Cell
;
Deglutition Disorders
;
Diet
;
Drug Therapy
;
Esophageal Neoplasms*
;
Esophagus
;
Female
;
Follow-Up Studies
;
Gastrostomy
;
Humans
;
Lymphatic Diseases
;
Male
;
Middle Aged
;
Multivariate Analysis
;
Radiotherapy*
;
Retrospective Studies
;
Survival Rate
;
Thorax
;
Tomography, X-Ray Computed
;
Treatment Outcome
3.Arthroscopic Repair for Acute Rupture of the Anterior Cruciate Ligament.
Sung Keun SOHN ; Kyung Taek KIM ; Nam Jo BAE ; Kyoung Sik HWANG
Journal of the Korean Knee Society 1999;11(1):39-44
The anterior cruciate ligament(ACL) is one of the most important structure for maintenance of the sta- bility of the knee joint. Chronic instability as a result of insufficiency can lead to functional disability, pain, meniscal tears, and degenerative change in articular cartilage. The incidence of injuries of this liga- ment is increasing tendency due to development of vehicle system, industrial system and sports activities. Different authors have recommended both operative and nonoperative treatment for anterior cruciate ligament injuries. Variable methods for functional recovery of anterior cruciate ligament were introduced and argued about ideal method. As arthroscopic techniques improve, surgeons are more inclined to rec- ommend surgical treatment. The methods of repair of acute rupture of the anterior cruciate ligament through the arthrotomy tech- nique have been used widely, but the arthroscopic repair is a relatively new technique. This arthroscopic technique is idealy applicable for rupture at femoral and tibial attachment site. A arthroscopic repair of anterior cruciate ligament was performed with use of the arthroscopy, in 15 consecutive, selected anterior cruciate ligaments that were ruptured at femoral or tibial attachment site, and within 2 weeks after injury. The 15 patients were followed for a minimum of one year(mean, eighteen months; maximum, thirty-eight months). The mean age of the 15 patients at the operation was thirty years(range, seventeen to forty-eight years). The results of arthroscopic repair of anterior cruciate ligament in 15 cases were satisfactory, and as fol- lows. l. All of the 15 cases, the laxity of repaired anterior cruciate ligaments were decreased. 2. The average Lysholm Knee Score Scale was increased from 16 points preoperatively to 89 points postoperatively. Five of the patients(33%) were rated as excellent, and ten patients(67%) were rated as good. 3. The range of motion of the repaired knee joints were from Oo to 135o that results were achieved at postoperative 6 months.
Anterior Cruciate Ligament*
;
Arthroscopy
;
Cartilage, Articular
;
Humans
;
Incidence
;
Knee
;
Knee Joint
;
Range of Motion, Articular
;
Rupture*
;
Sports
4.The Role of Radiotherapy for the Treatment of Gastric MALT Lymphoma.
Korean Journal of Medicine 2012;83(6):712-717
Gastric mucosa-associated lymphoid tissue (MALT) lymphoma represents approximately 9% of all malignant lymphoma in Korean, and its incidence is higher than that of western and other Asian countries. Helicobacter pylori eradication is the first line treatment in limited stage gastric MALT lymphoma. There is no consensus about initial treatment with chemotherapy or radiotherapy for the patient with insufficient response to H. pylori eradication or H. pylori negative. Radiotherapy is a conventional therapeutic modality and showed the excellent long term results. The radiotherapy for limited gastric MALT lymphoma shows that the 4-5-year disease free survival rate is 85-100% and acute toxicities is reasonable. However, only non-randomized studies support a role of local radiotherapy in gastric MALT lymphoma.
Asian Continental Ancestry Group
;
Consensus
;
Disease-Free Survival
;
Helicobacter pylori
;
Humans
;
Incidence
;
Lymphoid Tissue
;
Lymphoma
;
Lymphoma, B-Cell, Marginal Zone
5.A Prospective Randomized Study on Two Dose Fractionation Regimens of High-Dose-Rate Brachytherapy for Carcinoma of the Uterine Cervix: Comparison of Efficacies and Toxicities Between Two Regimens.
Journal of Korean Medical Science 2004;19(1):87-94
To evaluate the toxicities and efficacies of two fractionation regimens of high-doserate brachytherapy in uterine cervical cancer, patients were stratified by stage Ib- IIa versus IIb-IVa, and randomly assigned to receive 3 Gy fractions (group A) or 5 Gy fractions (group B). External radiotherapy was performed using a 10 MV radiography with a daily 1.8 Gy up to 30.6 Gy to the whole pelvis, and then with a midline shield up to 45.0 Gy. Brachytherapy was performed with 3 Gy x 10 times or 5 Gy x5 times, and this was followed by booster brachytherapy of a smaller fraction to the residual tumor. Between August 1999 to July 2000, 46 patients were eligible. Median follow-up period was 42 months (5-49). The range of age was 37-83 yr (median, 58). The three-year disease-specific survival rates of group A (n=23) and B (n=23) were 90.5%, 84.9%, respectively (p=0.64). The three-year pelvic control rates of group A and B were 90.0% and 90.9%, respectively (p=0.92). The incidences of late complications of the rectum or bladder of grade 2 or greater in groups A and B were 23.8% and 9.1%, respectively (p=0.24). Our study showed that the results of two regimens were comparable. Fractionation regimen using 5 Gy fractions seems to be safe and effective, and offers shorter treatment duration.
Adult
;
Aged
;
Aged, 80 and over
;
Brachytherapy/*methods
;
Carcinoma/mortality/*radiotherapy
;
Cervix Neoplasms/mortality/*radiotherapy
;
Combined Modality Therapy
;
Disease-Free Survival
;
*Dose Fractionation
;
Female
;
Human
;
Middle Aged
;
Prospective Studies
;
Time Factors
;
Treatment Outcome
6.Radiation-Induced Apoptosis of Lymphocytes in Peripheral Blood.
Yoon Kyeong OH ; Tae Bum LEE ; Taek Keun NAM ; Keun Hong KEE ; Cheol Hee CHOI
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2003;21(1):75-81
PURPOSE: This study quantitatively evaluated the apoptosis in human peripheral blood lymphocytes using flow cytometry, and investigated the possibility of using this method, with a small amount of blood, and the time and dose dependence of radiation-induced apoptosis. MATERIALS AND METHODS: Peripheral blood lymphocytes were isolated from the heparinized venous blood of 11 healthy volunteers, 8 men and 3 women, with each 10 ml of blood being divided into 15 samples. The blood lymphocytes were irradiated using a linear accelerator at a dose rate of 2.4 Gy/min, to deliver doses of 0.5, 1, 2 and 5 Gy. The control samples, and irradiated cells, were maintained in culture medium for 24, 48 and 72 hours following the irradiation. The number of apoptotic cells after the in vitro X-irradiation was measured by flow cytometry after incubation periods of 24, 48 and 72 hours. We also observed the apoptotic cells using a DNA fragmentation assay and electron microscopy. RESULTS: The rate of spontaneous apoptosis increased in relation to the time interval following irradiation (1.761+/-0.161, 3.563+/-0.564, 11.098+/-2.849, at 24, 48, and 72 hours). The apoptotic cells also increased in the samples irradiated with 0.5, 1, 2 and 5 Gy, in a radiation dose and time interval after irradiation manner, with the apoptosis being too great at 72 hours after irradiation. The dose-response curves were characterized by an initial steep increase in the number of apoptotic cells for irradiation doses below 2 Gy, with a flattening of the curves as the dose approached towards 5 Gy. CONCLUSION: The flow cytometric assay technique yielded adequate data, and required less than 1 mL of blood. The time and dose dependence of the radiation-induced apoptosis, was also shown. It is suggested that the adequate time interval required for the evaluation of apoptosis would be 24 to 48 hours after blood sampling.
Apoptosis*
;
DNA Fragmentation
;
Female
;
Flow Cytometry
;
Healthy Volunteers
;
Heparin
;
Humans
;
Lymphocytes*
;
Male
;
Microscopy, Electron
;
Particle Accelerators
7.Personalized Combined Modality Therapy for Locally Advanced Non-small Cell Lung Cancer.
D Nathan KIM ; Taek Keun NAM ; Kevin S CHOE ; Hak CHOY
Cancer Research and Treatment 2012;44(2):74-84
Locally advanced non-small cell lung cancer (NSCLC) is a heterogeneous disease, and we have embarked on an era where patients will benefit from individualized therapeutic strategies based on identifiable molecular characteristics of the tumor. The landmark studies demonstrating the importance of molecular characterization of tumors for NSCLC patients, the promising molecular pathways, and the potential molecular targets/agents for treatment of this disease will be reviewed. Understanding these issues will aid in the development of rationally designed clinical trials, so as to determine best means of appropriately incorporating these molecular strategies, to the current standard of radiation and chemotherapy regimens, for the treatment of locally advanced NSCLC.
Carcinoma, Non-Small-Cell Lung
;
Combined Modality Therapy
;
Humans
;
Precision Medicine
;
Lung Neoplasms
;
Receptor, Epidermal Growth Factor
8.Cytocompatibility of thermally oxidized Ti-Ag alloys.
Ho Joong KIM ; Keun Taek OH ; Zi Whan EE ; Kyoung Nam KIM ; Dong Hoo HAN
The Journal of Korean Academy of Prosthodontics 2004;42(4):333-343
STATEMENT OF PROBLEM: In its preceding work, change in surface characteristics were investigated in consideration that both microtopograpy and macroscopic configuration of implants surface are two of the most important factors, in that they can construct agreeable environment by raising surface energy, to affect osseointegration and biocompatibility explained by cell proliferation. PURPOSE: This study focused on examining cytocompatibility of dental implants materials Ti-Ag alloys, of which mechanical and electrochemical superiority to cp-Ti or Ti6Al4V were verified, in comparison with that of cp-Ti, and Ti6Al4V. MATERIALS AND METHODS: In this regard, MTT tests for L-929, the fibroblast connective tissues and cell proliferation tests for osteoprogenitor cells, MC3T3-E1 were performed on cp-Ti, Ti6Al4V, and Ti-Ag alloys following thermal oxidation according to appropriate heat treatment temperature(untreated, 400, 600, 800degrees C) and heat treatment duration(untreated, 0.5, 1, 4 hr). RESULTS: The MTT tests on fibroblasts L-929 resulted in cell viability of over 90% in all experimental group entities, where, especially, the 100% of the viability for Ti-Ag alloys specimens accounted for the slightest adverse effect of ions release from those alloys on the cell. In MC3T3-E1 proliferation tests, the population of cells in the experimental group was roughly increased as experimentation proceeded, after two to four days. Proliferation showed highest viability for most of specimens, including Ti2.0Ag, treated at 600degrees C. CONCLUSION: In conclusion, it is the heat treatment temperature, not the duration that has considerable effects on thermal oxidation of specimens. Ti-Ag alloys treated at 600degrees C proved to have the best surface morphology as well as cytocompatibility when compared with Ti or Ti6Al4V for short-term biocompatibility tests.
Alloys*
;
Cell Proliferation
;
Cell Survival
;
Connective Tissue
;
Dental Implants
;
Fibroblasts
;
Hot Temperature
;
Ions
;
Osseointegration
9.Postoperative Radiotherapy in Malignant Tumors of the Parotid Gland.
Woong Ki CHUNG ; Sung Ja AHN ; Taek Keun NAM ; Kyung Ae CHUNG ; Byung Sik NAH
The Journal of the Korean Society for Therapeutic Radiology and Oncology 1998;16(3):251-258
PURPOSE: This study was performed to analyze the factors affecting local control in malignant tumors of the parotid gland treated with surgery and postoperative radiation. MATERIALS AND METHODS: Twenty-six patients were treated for malignant tumors of the parotid gland from 1986 to 1995 at Department of Therapeutic Radiology, Chonnam University Hospital. Age of the patients ranged from 14 to 72 years (median : 55 years). Histologically 10 patients of mucoepidermoid carcinoma, 7 of squamous cell carcinoma, 4 of acinic cell carcinoma, 4 of adenoid cystic carcinoma and 1 of adenocarcinoma were treated. Total parotidectomy was performd in 15 of 26 patients, superficial in 7, subtotal in 4. Facial nerve was sacrificed in 5 patients. Postoperatively 4 patients had residual disease, 4 had positive resection margin. Radiation was delivered through an ipsilateral wedged pair of photon in 11 patients. High energy electron beam was mixed with photon in 15 patients. Electron beam dose ranged from 900 cGy to 3800 cGy (median : 1760 cGy). Total radiation dose ranged from 5000 cGy to 7560 cGy (median : 6020 cGy). Minimum follow-up period was 2 years. Local control and survival rate were calculated using Kaplan-Meier method. Generalized Wilcoxon test and Cox proportional hazard model were used to test factors affecting local control. RESULTS: Five (19%) of 26 patients had local recurrence. Five year local control rate was 77%. Overall five year survival rate was 70%. Sex, age, tumor size, surgical involvement of cervical lymph node, involvement of resection margin, surgical invasion of nerve, and total dose were analyzed as suggested factors affecting local control rate. Among them patients with tumor size less than 4 cm (p=0.002) and negative resection margin (p= 0.011) were associated with better local control rates in univariate analysis.Multivariate analysis showed only tumor size factor is associated with local control rate (p=0.022). CONCLUSION: This study suggested that tumor size is important in local control of malignant tumors of parotid gland.
Adenocarcinoma
;
Carcinoma, Acinar Cell
;
Carcinoma, Adenoid Cystic
;
Carcinoma, Mucoepidermoid
;
Carcinoma, Squamous Cell
;
Facial Nerve
;
Fibrinogen
;
Follow-Up Studies
;
Humans
;
Jeollanam-do
;
Lymph Nodes
;
Parotid Gland*
;
Proportional Hazards Models
;
Radiation Oncology
;
Radiotherapy*
;
Recurrence
;
Survival Rate
10.Analysis of Respiratory Motional Effect on the Cone-beam CT Image.
Ju Young SONG ; Byung Sik NAH ; Woong Ki CHUNG ; Sung Ja AHN ; Taek Keun NAM ; Mi Sun YOON
Korean Journal of Medical Physics 2007;18(2):81-86
The cone-beam CT (CBCT) which is acquired using on-board imager (OBI) attached to a linear accelerator is widely used for the image guided radiation therapy. In this study, the effect of respiratory motion on the quality of CBCT image was evaluated. A phantom system was constructed in order to simulate respiratory motion. One part of the system is composed of a moving plate and a motor driving component which can control the motional cycle and motional range. The other part is solid water phantom containing a small cubic phantom (2 x 2 x 2 cm3) surrounded by air which simulate a small tumor volume in the lung air cavity. CBCT images of the phantom were acquired in 20 different cases and compared with the image in the static status. The 20 different cases are constituted with 4 different motional ranges (0.7 cm, 1.6 cm, 2.4 cm, 3.1 cm) and 5 different motional cycles (2, 3, 4, 5, 6 sec). The difference of CT number in the coronal image was evaluated as a deformation degree of image quality. The relative average pixel intensity values as a compared CT number of static CBCT image were 71.07% at 0.7 cm motional range, 48.88% at 1.6 cm motional range, 30.60% at 2.4 cm motional range, 17.38% at 3.1 cm motional range. The tumor phantom sizes which were defined as the length with different CT number compared with air were increased as the increase of motional range (2.1 cm: no motion, 2.66 cm: 0.7 cm motion, 3.06 cm: 1.6 cm motion, 3.62 cm: 2.4 cm motion, 4.04 cm: 3.1 cm motion). This study shows that respiratory motion in the region of inhomogeneous structures can degrade the image quality of CBCT and it must be considered in the process of setup error correction using CBCT images.
Cone-Beam Computed Tomography*
;
Lung
;
Particle Accelerators
;
Radiotherapy, Image-Guided
;
Tumor Burden
;
Water