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1.
Radiation Oncology Journal ; : 60-67, 2020.
Article | WPRIM | ID: wpr-837102

ABSTRACT

Purpose@#We performed three-dimensional (3D) dose reconstruction-based pretreatment verification to evaluate gamma analysis acceptance criteria in volumetric modulated arc therapy (VMAT) for prostate cancer. @*Materials and Methods@#Pretreatment verification for 28 VMAT plans for prostate cancer was performed using the COMPASS system with a dolphin detector. The 3D reconstructed dose distribution of the treatment planning system calculation (TC) was compared with that of COMPASS independent calculation (CC) and COMPASS reconstruction from the dolphin detector measurement (CR). Gamma results (gamma failure rate and average gamma value [GFR and γAvg]) and dose-volume histogram (DVH) deviations, 98%, 2% and mean dose-volume difference (DD98%, DD2% and DDmean), were evaluated. Gamma analyses were performed with two acceptance criteria, 2%/2 mm and 3%/3 mm. @*Results@#The GFR in 2%/2 mm criteria were less than 8%, and those in 3%/3 mm criteria were less than 1% for all structures in comparisons between TC, CC, and CR. In the comparison between TC and CR, GFR and γAvg in 2%/2 mm criteria were significantly higher than those in 3%/3 mm criteria. The DVH deviations were within 2%, except for DDmean (%) for rectum and bladder. @*Conclusions@#The 3%/3 mm criteria were not strict enough to identify any discrepancies between planned and measured doses, and DVH deviations were less than 2% in most parameters. Therefore, gamma criteria of 2%/2 mm and DVH related parameters could be a useful tool for pretreatment verification for VMAT in prostate cancer.

2.
Cancer Research and Treatment ; : 1074-1083, 2016.
Article in English | WPRIM | ID: wpr-68887

ABSTRACT

PURPOSE: We evaluated the role of adjuvant therapy in stage IIIA endometrioid adenocarcinoma patients who underwent surgery followed by radiotherapy (RT) alone or chemoradiotherapy (CTRT) according to risk group. MATERIALS AND METHODS: A multicenter retrospective study was conducted including patients with surgical stage IIIA endometrial cancertreated by radical surgery and adjuvant RT or CTRT. Disease-free survival (DFS) and overall survival (OS) were analyzed. RESULTS: Ninety-three patients with stage IIIA disease were identified. Nineteen patients (20.4%) experienced recurrence, mostly distant metastasis (17.2%). Combined CTRT did not affect DFS (74.1% vs. 82.4%, p=0.130) or OS (96.3% vs. 91.9%, p=0.262) in stage IIIA disease compared with RT alone. Patients with age ≥ 60 years, grade G2/3, and lymphovascular space involvement had a significantly worse DFS and those variables were defined as risk factors. The high-risk group showed a significant reduction in 5-year DFS (≥ 2 risk factors) (49.0% vs. 88.0%, p < 0.001) compared with the low-risk group (< 2). Multivariate analysis confirmed that more than one risk factor was the only predictor of worse DFS (hazard ratio, 5.45; 95% confidence interval, 2.12 to 13.98; p < 0.001). Of patients with no risk factors, a subset treated with RT alone showed an excellent 5-year DFS and OS (93.8% and 100%, respectively). CONCLUSION: We identified a low-risk subset of stage IIIA endometrioid adenocarcinoma patients who might be reasonable candidates for adjuvant RT alone. Further randomized studies are needed to determine which subset might benefit from combined CTRT.


Subject(s)
Female , Humans , Adenocarcinoma , Carcinoma, Endometrioid , Chemoradiotherapy , Chemoradiotherapy, Adjuvant , Disease-Free Survival , Endometrial Neoplasms , Multivariate Analysis , Neoplasm Metastasis , Radiotherapy , Radiotherapy, Adjuvant , Recurrence , Retrospective Studies , Risk Factors
3.
Radiation Oncology Journal ; : 75-82, 2015.
Article in English | WPRIM | ID: wpr-113862

ABSTRACT

PURPOSE: We evaluated the prognostic significance of T3 subtypes and the role of adjuvant radiotherapy in patients with resected the American Joint Committee on Cancer stage IIB T3N0M0 non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: T3N0 NSCLC patients who underwent resection from January 1990 to October 2009 (n = 102) were enrolled and categorized into 6 subgroups according to the extent of invasion: parietal pleura chest wall invasion, mediastinal pleural invasion, diaphragm invasion, separated tumor nodules in the same lobe, endobronchial tumor <2 cm distal to the carina, and tumor-associated collapse. RESULTS: The median overall survival (OS) and disease-free survival (DFS) were 55.3 months and 51.2 months, respectively. In postoperative T3N0M0 patients, the tumor size was a significant prognostic factor for survival (OS, p = 0.035 and DFS, p = 0.035, respectively). Patients with endobronchial tumors within 2 cm of the carina also showed better OS and DFS than those in the other T3 subtypes (p = 0.018 and p = 0.016, respectively). However, adjuvant radiotherapy did not cause any improvement in survival (OS, p = 0.518 and DFS, p = 0.463, respectively). Only patients with mediastinal pleural invasion (n = 25) demonstrated improved OS and DFS after adjuvant radiotherapy (n = 18) (p = 0.012 and p = 0.040, respectively). CONCLUSION: The T3N0 NSCLC subtype that showed the most favorable prognosis is the one with endobronchial tumors within 2 cm of the carina. Adjuvant radiotherapy is not effective in improving survival outcome in resected T3N0 NSCLC.


Subject(s)
Humans , Carcinoma, Non-Small-Cell Lung , Diaphragm , Disease-Free Survival , Joints , Pleura , Prognosis , Radiotherapy, Adjuvant , Thoracic Wall
4.
Imaging Science in Dentistry ; : 43-52, 2014.
Article in English | WPRIM | ID: wpr-12990

ABSTRACT

PURPOSE: This study was designed to evaluate whether magnetic resonance imaging (MRI) is appropriate for detecting early changes in the mandibular bone marrow and pulp tissue of rats after high-dose irradiation. MATERIALS AND METHODS: The right mandibles of Sprague-Dawley rats were irradiated with 10 Gy (Group 1, n=5) and 20 Gy (Group 2, n=5). Five non-irradiated animals were used as controls. The MR images of rat mandibles were obtained before irradiation and once a week until week 4 after irradiation. From the MR images, the signal intensity (SI) of the mandibular bone marrow and pulp tissue of the incisor was interpreted. The MR images were compared with the histopathologic findings. RESULTS: The SI of the mandibular bone marrow had decreased on T2-weighted MR images. There was little difference between Groups 1 and 2. The SI of the irradiated groups appeared to be lower than that of the control group. The histopathologic findings showed that the trabecular bone in the irradiated group had increased. The SI of the irradiated pulp tissue had decreased on T2-weighted MR images. However, the SI of the MR images in Group 2 was high in the atrophic pulp of the incisor apex at week 2 after irradiation. CONCLUSION: These patterns seen on MRI in rat bone marrow and pulp tissue were consistent with histopathologic findings. They may be useful to assess radiogenic sclerotic changes in rat mandibular bone marrow.


Subject(s)
Animals , Rats , Bone Marrow , Incisor , Magnetic Resonance Imaging , Mandible , Rats, Sprague-Dawley
5.
Tuberculosis and Respiratory Diseases ; : 81-94, 2010.
Article in Korean | WPRIM | ID: wpr-100696

ABSTRACT

BACKGROUND: Autophagy is an important adaptive mechanism in normal development and in response to changing environmental stimuli in cancer. Previous papers have reported that different types of cancer underwent autophagy to obtain amino acids as energy source of dying cells in nutrient-deprived conditions. However, whether or not autophagy in the process of lung cancer causes death or survival is controversial. Therefore in this study, we investigated whether nutrient deprivation induces autophagy in human H460 lung cancer cells. METHODS: H460, lung cancer cells were incubated in RPMI 1640 medium, and the starved media, which are BME and RPMI media without serum, including 2-deoxyl-D-glucose according to time dependence. To evaluate the viability and find out the mechanism of cell death under nutrient-deprived conditions, the MTT assay and flow cytometry were done and analyzed the apoptotic and autophagic related proteins. It is also measured the development of acidic vascular organelles by acridine orange. RESULTS: The nutrient-deprived cancer cell is relatively sensitive to cell death rather than normal nutrition. Massive cytoplasmic vacuolization was seen under nutrient-deprived conditions. Autophagic vacuoles were visible at approximately 12 h and as time ran out, vacuoles became larger and denser with the increasing number of vacuoles. In addition, the proportion of acridine orange stain-positive cells increased according to time dependence. Localization of GFP-LC3 in cytoplasm and expression of LC-3II and Beclin 1 were increased according to time dependence on nutrient-deprived cells. CONCLUSION: Nutrient deprivation induces cell death through autophagy in H460 lung cancer cells.


Subject(s)
Humans , Acridine Orange , Amino Acids , Autophagy , Cell Death , Cytoplasm , Flow Cytometry , Lung Neoplasms , Malnutrition , Organelles , Proteins , Vacuoles
6.
Korean Journal of Medical Physics ; : 78-85, 2010.
Article in Korean | WPRIM | ID: wpr-30101

ABSTRACT

The compatibility with GammaMed-12i brachytherapy machine for an Ir-192 encapsulated source (IRRS20, KAERI, Korea) manufactured by Korea atomic energy research institute (KAERI) has been investigated. As a mechanical testing of compatibility, precise measurement of step movement with channels, measurement of curvature of radius for wire, and emergency return testing were performed. Periodic measurements of air kerma strength for 45 days were carried out to evaluate decay characteristics of Ir-192 radioisotope and comparison of dose distributions in phantom between KAERI and old sources previously used were performed by film dosimetry. KAERI source has a good compatibility with GammaMed12i machine as a result of mechanical testing. There are in good agreement with calculated values in activity characteristics and there were small differences in dose distributions around the source in comparison between KAERI and old source.


Subject(s)
Academies and Institutes , Brachytherapy , Emergencies , Film Dosimetry , Korea , Nuclear Energy , Radius
7.
Korean Journal of Medical Physics ; : 30-36, 2009.
Article in Korean | WPRIM | ID: wpr-88370

ABSTRACT

The quality correction in the air kerma dosimetry for Ir-192 using farmer type ionization chambers calibrated by Co-60 quality is required. In this study we determined quality factor (kappa u) of two ionization chambers of PTW-N30001 and N23333 for Ir-192 source using dosimetric method. The quality factors for energy spectrum of microSelectron were determined as kappa u=1.016 and 1.017 for PTW-N30001 and N23333 ionization chambers respectively. We applied quality factors in air kerma dosimetry for microSelectron source and compared with reference values. As a results we found that the differences between reference air kerma rate and measured it with and without quality correction were about -0.5% and -2.0% respectively.


Subject(s)
Gamma Rays , Reference Values
8.
Korean Journal of Medical Physics ; : 43-50, 2009.
Article in Korean | WPRIM | ID: wpr-88368

ABSTRACT

The 4 bank mico-MLC (mMLC; Acculeaf, Direx, Isral) has been commissioned for clinical use of linac based stereotactic radiosurgery. The geometrical parameters to control the leaves were determined and comparisons between measured and calculated by the calculation model were performed in terms of absolute dose (cGy/100 MU). As a result of evaluating calculated dose for various field sizes and depths of 5 and 10 cm in water in the geometric condition of fixed SSD (source to surface distance) and fixed SCD (source to chamber distance), most of differences were within 1% for 6 MV and 15 MV x-rays. The penumbral widths at the isocenter were approximately evaluated to 0.29~0.43 cm depending on the field size for 6 MV and 0.36~0.51 cm for 15 MV x-rays. The average transmission and leakage for 6 MV and 15 MV x-rays were 6.6% and 7.4% respectively in single level of leaves fully closed. In case of dual level of leaves fully closed the measured transmission is approximately 0.5% for both 6 MV and 15 MV x-rays. Through the commissiong procedure we could verify the dose characteristics of mMLC and approximately evaluate the error ranges for treatment planning system.


Subject(s)
Radiosurgery , Silver Sulfadiazine , Water
9.
Tuberculosis and Respiratory Diseases ; : 444-450, 2009.
Article in Korean | WPRIM | ID: wpr-73517

ABSTRACT

BACKGROUND: Biomarkers for cancer have several potential clinical uses, including the following: early cancer detection, monitoring for recurrence prognostication, and risk stratification. However, no biomarker has been shown to have adequate sensitivity and specificity. Many investigators have tried to validate biomarkers for the early detection and recurrence of lung cancer. To evaluate plasma G-CSF as such a biomarker, protein levels were measured and were found to correlate with the clinicopathological features of primary lung tumors. METHODS: Between December 2006 and May 2008, 100 patients with histologically-validated primary lung cancer were enrolled into this study. To serve as controls, 127 healthy volunteers were enrolled into this study. Plasma G-CSF levels were measured in lung cancer patients using the sandwich ELISA system (R & D inc.) prior to treatment. RESULTS: The mean plasma G-CSF levels were 12.2+/-0.3 pg/mL and 46.0+/-3.8 pg/mL (mean+/-SE) in the normal and in the cancer groups, respectively. In addition, plasma G-CSF levels were higher in patients with early lung cancer than in healthy volunteers (p<.001). Plasma G-CSF levels were higher in patients who were under 65 years old or smokers. Within the cancer group, plasma G-CSF levels were higher in patients with non small cell lung cancer than in patients with small cell lung cancer (p<.05). Overall, plasma G-CSF levels were shown to increase dependent upon the type of lung cancer diagnsosed. In the order from highest to lowest, the levels of plasma G-CSF tended to decrease in the following order: large cell carcinoma, squamous cell carcinoma, adenocarcinoma, and bronchioloalveolar carcinoma. Plasma G-CSF levels tended to be higher in patients with advanced TNM stage than in localized TNM stage (I, II

Subject(s)
Humans , Adenocarcinoma , Adenocarcinoma, Bronchiolo-Alveolar , Adrenal Glands , Biomarkers , Carcinoma, Large Cell , Carcinoma, Squamous Cell , Enzyme-Linked Immunosorbent Assay , Granulocyte Colony-Stimulating Factor , Lung , Lung Neoplasms , Neoplasm Metastasis , Plasma , Recurrence , Research Personnel , Small Cell Lung Carcinoma
10.
Tuberculosis and Respiratory Diseases ; : 362-368, 2008.
Article in Korean | WPRIM | ID: wpr-97155

ABSTRACT

BACKGROUND: LKB1(STK11) is a serine/threonine kinase that functions as a tumor growth suppressor. The functions of LKB1 in lung cancer are not completely understood. This study evaluated the relationship between LKB1 protein expression and the clinicopathological features in lung cancer tissues. METHODS: The expression of LKB1 was studied in paraffin-embedded tumor blocks, which were obtained from 77 patients who had undergone surgery at Wonkwang University Hospital. The expression of the LKB1 protein was considered positive if the staining intensity in the tumor tissue adjacent to the normal airway epithelium was >30%. RESULTS: The LKB1 expression was positive in 31 (40%) of samples. Loss of LKB1 expression was significantly associated with being male, smoking history, and squamous cell carcinoma. In the peripheral sites, the loss of LKB1 expression was strongly associated with a smoking history. A loss of LKB1 expression was more frequently associated with progression according to TNM staging, particularly more than T2, N progression. CONCLUSION: There was a significant relationship between the loss of the LKB1 protein and gender, smoking history, and histological type in primary lung cancer. Although LKB1 expression was not found to be a significant prognostic factor, further studies with a larger cohort of patient's lung cancer tissue samples will be needed to confirm this.


Subject(s)
Humans , Male , Carcinoma, Squamous Cell , Cohort Studies , Epithelium , Lung , Lung Neoplasms , Neoplasm Staging , Phosphotransferases , Smoke , Smoking
11.
Korean Journal of Medical Physics ; : 56-62, 2008.
Article in Korean | WPRIM | ID: wpr-203475

ABSTRACT

In this study, we have investigated the dose characteristics of PTW-LinaCheck designed to detect output of medical LINAC and discussed clinical use of the detector. The reproducibility, linearity, and dose rate dependency of the dosimeter were measured for photons of 6 and 15 MV and the electrons of 4, 6, 9, 12, and 16 MeV. To know the error ranges of the measured data in daily output measurement, the response variations due to geometrical setup errors were measured. As a result of measurement, the error range from the geometrical setup and the reproducibility was less than +/-0.6% for given beam qualities in daily output measurement, where the errors from the linearity and the dose rate dependency were negligible. Finally, we concluded that the LinaCheck dosimeter has a good characteristics in terms of dose and setup convenience in daily output measurement. In addition we have shown an examples of clinical use of this dosimeter for measuring daily output more than 60 days.


Subject(s)
Dependency, Psychological , Electrons , Photons
12.
Korean Journal of Medical Physics ; : 131-138, 2008.
Article in Korean | WPRIM | ID: wpr-7196

ABSTRACT

We evaluated on the calculation accuracy of treatment planning system (TPS) with phantom having convex and concave surface. The TPS is Eclipse (Varian, USA) using both algorithms AAA and PBC for photon dose calculations. PBC algorithms have three corrections of Batho, modified Batho (M-Batho), and equivalent TAR (E-TAR). The field sizes were 10x10 cm2 and 20x20 cm2, and MLC-shaped fields for these fields. We measured doses at three depths 5, 10 and 15 cm in phantom of SSD=90 cm in the condition of inserted farmer chamber. For given conditions, we have calculated dose with these algorithms and compared them with measured doses. In AAA the calculated doses (dose/MU) were agreed to measured doses within +/-1% in flat and convex surface and were under estimated with -1.9% maximum in concave surface. In PBC the calculated doses were over estimated with +1.7% and +4.1% respectively in flat and convex surface and the differences were from -3.1% to +2.1% in concave surface. In comparison of criteria from AAPM and IAEA reports, and statistical analysis for these results, it is found that the AAA's results are in good agreement with measured values and the M-Batho's results are generally good agreed with measured values among PBC algorithms.


Subject(s)
Water
13.
The Journal of the Korean Society for Therapeutic Radiology and Oncology ; : 242-248, 2007.
Article in Korean | WPRIM | ID: wpr-159792

ABSTRACT

PURPOSE: To study the effect of recombinant human epidermal growth factor (rhEGF) on oral mucositis induced by cisplatin and radiotherapy in a mouse model. MATERIALS AND METHODS: Twenty-four ICR mice were divided into three groups? the normal control group, the no rhEGF group (treatment with cisplatin and radiation) and the rhEGF group (treatment with cisplatin, radiation and rhEGF). A model of mucositis induced by cisplatin and radiotherapy was established by injecting mice with cisplatin (10 mg/kg) on day 1 and with radiation exposure (5 Gy/day) to the head and neck on days 1~5. rhEGF was administered subcutaneously on days -1 to 0 (1 mg/kg/day) and on days 3 to 5 (1 mg/kg/day). Evaluation included body weight, oral intake, and histology. RESULTS: For the comparison of the change of body weight between the rhEGF group and the no rhEGF group, a statistically significant difference was observed in the rhEGF group for the 5 days after day 3 of the experiment. The rhEGF group and no rhEGF group had reduced food intake until day 5 of the experiment, and then the mice demonstrated increased food intake after day 13 of the of experiment. When the histological examination was conducted on day 7 after treatment with cisplatin and radiation, the rhEGF group showed a focal cellular reaction in the epidermal layer of the mucosa, while the no rhEGF group did not show inflammation of the oral mucosa. CONCLUSION: These findings suggest that rhEGF has a potential to reduce the oral mucositis burden in mice after treatment with cisplatin and radiation. The optimal dose, number and timing of the administration of rhEGF require further investigation.


Subject(s)
Animals , Humans , Mice , Body Weight , Cisplatin , Eating , Epidermal Growth Factor , Head , Inflammation , Mice, Inbred ICR , Mouth Mucosa , Mucositis , Mucous Membrane , Neck , Radiotherapy , Stomatitis
14.
Korean Journal of Medical Physics ; : 53-61, 2005.
Article in Korean | WPRIM | ID: wpr-187037

ABSTRACT

The quality factors for cylindrical ionization chambers for kV X-rays were determined by Monte Carlo calculation and measurement. In this study, the X-rays of 60~300 kV beam (ISO-4037) installed in KFDA and specified in energy spectra and beam qualities, and the chambers of PTW N23333 and N30001 were investigated. In calculations, the k(u) and k(Q,Q(0)) in IAEA dosimetry protocols were determined from the air kerma and the cavity dose obtained by theoretical and Monte Carlo calculations. It is shown that the N30001 chamber has a flat response of +/-1.7% in 110~300 kV region, while the response range of two chambers were shown to +/-3~4% in 80~250 kV region. From this work we have discussed dosimetry protocol for the kV X-rays and we have found that the estimation of energy dependency is more important to apply dosimetry protocol for kV X-rays.

15.
The Journal of the Korean Society for Therapeutic Radiology and Oncology ; : 192-199, 2004.
Article in Korean | WPRIM | ID: wpr-177350

ABSTRACT

PURPOSE: To determine the patterns of evaluation and treatment in the patient with early breast cancer treated with conservative surgery and radiotherapy and to improve the radiotherapy techiniques, nationwide survey was performed. MATERIALS AND METHODS: A web-based database system for Korean Patterns of Care Study (PCS) for 6 common cancers was developed. Two hundreds sixty-one randomly selected records of eligible patients treated between 1998~999 from 15 hospitals were reviewed. RESULTS: The patients ages ranged from 24 to 85 years(median 45 years). Infiltrating ductal carcinoma was most common histologic type (88.9%) followed by medullary carcinoma (4.2%) and infiltrating lobular carcinoma (1.5%). Pathologic T stage by AJCC was T1 in 59.7% of the casses, T2 in 29.5% of the cases, Tis in 8.8% of the cases. Axillary lymph node dissection was performed in 91.2% of the cases and 69.7% were node negative. AJCC stage was 0 in 8.8% of the cases, stage I in 44.9% of the cases, stage IIa in 33.3% of the cases, and stage IIb in 8.4% of the cases. Estrogen and progesteron receptors were evaluated in 71.6%, and 70.9% of the patients, respectively. Surgical methods of breast-conserving surgery was excision/lumpectomy in 37.2%, wide excision in 11.5%, quadrantectomy in 23% and partial mastectomy in 27.5% of the cases. A pathologically confirmed negative margin was obtained in 90.8% of the cases. Pathological margin was involved with tumor in 10 patients and margin was close (less than 2 mm) in 10 patients. All the patients except one recieved more than 90% of the planned radiotherapy dose. Radiotherapy volume was breast only in 88% of the cases, breast+supraclavicular fossa (SCL) in 5% of the cases, and breast+SCL+posterior axillary boost in 4.2% of the cases. Only one patient received isolated internal mammary lymph node irradiation. Used radiation beam was Co-60 in 8 cases, 4 MV X-ray in 115 cases, 6 MV X-ray in 125 cases, and 10 MV X-ray in 11 cases. The radiation dose to the whole breast was 45~9.4 Gy (median 50.4) and boost dose was 8~20 Gy (median 10 Gy). The total radiation dose delivered was 50.4~70.4 Gy (median 60.4 Gy). CONCLUSION: There was no major deviation from current standard in the patterns of evaluation and treatment for the patients with early breast cancer treated with breast conservation method. Some varieties were identified in boost irradiation dose. Separate analysis for the datails of radiotherapy planning will be followed and the outcome of treatment is needed to evaluate the process.


Subject(s)
Humans , Breast Neoplasms , Breast , Carcinoma, Ductal , Carcinoma, Lobular , Carcinoma, Medullary , Estrogens , Korea , Lymph Node Excision , Lymph Nodes , Mastectomy, Segmental , Radiotherapy
16.
Journal of Lung Cancer ; : 133-136, 2004.
Article in Korean | WPRIM | ID: wpr-65604

ABSTRACT

Thymic carcinoma is a rare neoplasm arising in the thymic epithelium. The prognosis of thymic carcinoma is often poor with an aggressive histologic appearance and clinical course. However, few studies about efficacy of treatment modalities have been published because of the rarity of this tumor. Although resection of tumor is the first choice in the treatment of thymic carcinoma, the optimal adjuvant therapy has yet to be defined. A case showed that a patient with thymic carcinoma should be treated by tumor resection followed by radiotherapy alone. And we consider proper management for thymic carcinoma with reviewing literatures


Subject(s)
Humans , Drug Therapy , Epithelium , Prognosis , Radiotherapy , Thymoma
17.
The Journal of the Korean Society for Therapeutic Radiology and Oncology ; : 322-329, 2003.
Article in Korean | WPRIM | ID: wpr-126372

ABSTRACT

PURPOSE: It is difficult to exactly determine the surface dose and the dose distribution in buildup region of high energy X-rays by using the conventional ion chamber. The aim of this study is to evaluate the accuracy of widely used dosimetry systems to measure the surface dose and the depth of maximum dose (dmax). MATERIALS AND METHODS: We measured the percent depth dose (PDD) from the surface to the dmax in either a water phantom or in a solid water phantom using TLD-100 chips, thimble type ion chamber, diode detector, diamond detector and Markus parallel plate ion chamber for 6 MV and 15 MV X-rays, 10 10 cm2, at SSD=100 cm. We analysed the surface dose and the dmax. In order to verify the accuracy of the TLD data, we executed the Monte Carlo simulation for 6 MV X-ray beams. RESULTS: The surface doses in 6 MV and 15 MV X-rays were 29.31% and 23.36% for Markus parallel plate ion chamber, 37.17% and 24.01% for TLD, 34.87% and 24.06% for diamond detector, 38.13% and 27.8% for diode detector, and 47.92% and 36.01% for thimble type ion chamber, respectively. In Monte Carlo simulation for 6 MV X-rays, the surface dose was 36.22%, which is similar to the 37.17% of the TLD measurement data. The dmax in 6 MV and 15 MV X-rays was 14~16 mm and 27~29 mm, respectively. There was no significant difference in the dmax among the detectors. CONCLUSION: There was a remarkable difference in the surface dose among the detectors. The Markus parallel plate chamber showed the most accurate result. The surface dose of the thimble ion chamber was 10% higher than that of other detectors. We suggest that the correction should be made when the surface dose of the thimble ion chamber is used for the treatment planning for the superficial tumors. All the detectors used in our study showed no difference in the dmax.


Subject(s)
Diamond , Water
18.
The Journal of the Korean Society for Therapeutic Radiology and Oncology ; : 334-342, 2002.
Article in Korean | WPRIM | ID: wpr-149295

ABSTRACT

PURPOSE: The aim of this study was to determine if postoperative adjuvant chemotherapy (CT) alone and concurrent chemoradiation (CCRT), following radical surgery, improved the disease free survival (DFS) and overall survival (OS) in rectal cancer AJCC stage II and III patients. MATERIALS AND METHODS: A total of 144 patients with AJCC stage II and III rectal cancer who had had radical surgery between 1989 and 1999 were included in the study. Of these patients, 72 had been treated with postoperative CT, and the other 72 with postoperative CCRT. The chemotherapy regimen consisted of oral UFT on a daily basis for 1~12 months (median 12 months) or 5-FU (500 mg/m2 for 5 days) intravenous (IV) chemotherapy with 4 week intervals for 1~18 cycles (median 6 cycles). Radiation of 4,500 cGy was delivered to the surgical bed and regional pelvic lymph nodes area, followed by 540~1,440 cGy (median 540 cGy) boost to the surgical bed. The follow-up period ranged from 20 to 150 months, with a median of 44 months. RESULTS: The 5-year OS was 60.9% and 68.9% (p=0.0915), and the 5-year DFS was 56.1% and 63.8% (p=0.3510) for postoperative CT and postoperative CCRT, respectively. In the stage II patients, the 5-year OS was 71.1% and 92.2%, and the 5-year DFS was 57.3% and 85.4% for postoperative CT and CCRT, respectively. The OS was significantly improved (p=0.0379) but the DFS was not with postoperative CCRT compared to the postoperative CT (p=0.1482). In the stage III patients, the 5-year OS was 52.0% and 55.0%, and the 5-year DFS was 47.8% and 49.8% for postoperative CT and postoperative CCRT. There were no statistically significant differences between postoperative CT and CCRT (p=0.4280 and p=0.7891) in OS and DFS. The locoregional relapses were 16.7% and 12.5% for postoperative CT and CCRT, respectively. The distant relapses were 25.0% and 26.4% for postoperative CT and CCRT, respectively. CONCLUSION: These results showed that postoperative CCRT compared with CT alone improved OS in stage II patients. Although there was no statistical significance, the addition of postoperative RT to CT reduced locoregional relapses compared to CT alone.


Subject(s)
Humans , Chemotherapy, Adjuvant , Disease-Free Survival , Drug Therapy , Fluorouracil , Follow-Up Studies , Lymph Nodes , Rectal Neoplasms , Recurrence
19.
Journal of the Korean Cancer Association ; : 21-26, 2001.
Article in Korean | WPRIM | ID: wpr-153905

ABSTRACT

PURPOSE: To define the clinical features and pattern of failure and to evaluate the results of radiation treatment in of adenosquamous cell carcinoma of the uterine cervix. MATERIALS AND METHODS: From Jun. 1981 to Dec. 1997, 43 patients with adenosquamous cell carcinoma of the uterine cervix were retrospectively analyzed external radiation treatment and HDR-ICR from Yonsei cancer center and Wonju cristian hospital. The median age was 51. Stage distribution according to FIGO were stage 1b in 10, 2a in 5, 2b in 18, 3b in 9, 4a in 1. Median follow-up period was 41 months. RESULTS: Overall survival rate and disease free survival rate were 57.2% and 60.2%. Complete response rate was 86.0%. Locoregional failure was observed in seven patients. CONCLUSION: Major pattern of failure was locoregional failure. Adenosquamous cell carcinoma was not more aggressive than other pathologic types.


Subject(s)
Female , Humans , Cervix Uteri , Disease-Free Survival , Follow-Up Studies , Retrospective Studies , Survival Rate , Uterine Cervical Neoplasms
20.
The Journal of the Korean Society for Therapeutic Radiology and Oncology ; : 335-344, 2001.
Article in Korean | WPRIM | ID: wpr-16900

ABSTRACT

PURPOSE: The aim of this study was to clarify the role of VEGF expression as an independent prognostic factor and to identify the patients at high risk for poor prognosis in stage IB cervical cancer. MATERIALS AND METHODS: A total of 118 patients with stage IB cervical cancer who had radical hysterectomy and pelvic lymph node dissection were included in the study. All known high risk factors of the patients were pathologically confirmed from the surgical specimen. Of the 118 patients, 88 patients were treated with postoperative radiotherapy and/or chemotherapy. VEGF expression was examined using immunohistochemistry in formalin-fixed, paraffin-embedded specimens of post-hysterectomy surgical materials. A semiquantitative analysis was made using a scoring system of 0, +, + +, and + + + for increasing intensity of stain. We classified the patients with scores from 0 to + + as low VEGF expression and the patients with a score of + + + as high VEGF expression. RESULTS: Of the 118 patients, 35 patients (29.7%) showed high VEGF expression. Strong correlations were found between the high VEGF expression and both deep stromal invasion (p=0.01) and the positive pelvic node (p=0.03). The 5-year overall and disease-free survival rates for all 118 patients were 95.5% and 93.8%. The 5-year overall (p=0.03) and disease-free survival (p<0.001) rates were 98.5% and 100% for low VEGF expression (0, +, and + +) and 85.5% and 79.7% for high VEGF expression, respectively. Pelvic and distant failures for low versus high VEGF expression were 1.2% versus 17.1%, (p=0.001) and 0% versus 14.3% (p<0.001), respectively. In a Cox multivariate analysis of survival, the high VEGF expression (p=0.02) and the bulky mass (p=0.02) were significant prognostic factors for overall survival. The high VEGF expression (p=0.002), and bulky mass (p=0.01) demonstrated as significant prognostic indicators for disease free survival. CONCLUSION: These results showed that VEGF expression was a highly significant predictor for pelvic and distant failure and the most significant prognostic factor of overall and disease free survival for the patients with stage IB cervix cancer treated with radical surgery. We strongly suggest that the immunohistochemistry for VEGF expression be performed in a routine clinical setting in order to identify the patients at high risk for poor prognosis in early stage cervical cancer. Furthermore, postoperative and/or chemotherapy did not reduce the pelvic failure and distant metastasis. To improve the cure rate for the patients with high VEGF expression in stage IB cervical cancer, antiangiogenic therapy including anti- VEGF Ab may be a new treatment option.


Subject(s)
Female , Humans , Cervix Uteri , Disease-Free Survival , Drug Therapy , Hysterectomy , Immunohistochemistry , Lymph Node Excision , Multivariate Analysis , Neoplasm Metastasis , Prognosis , Radiotherapy , Risk Factors , Uterine Cervical Neoplasms , Vascular Endothelial Growth Factor A
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