PURPOSE: Planning target volume (PTV) for tumors in abdomen or thorax includes enough margin for breathing-related movement of tumor volumes during treatment. Depending on the location of the tumor, the magnitude of PTV margin extends from 10 mm to 30 mm, which increases substantial volume of the irradiated normal tissue hence, resulting in increase of normal tissue complication probability (NTCP). We developed a simple and handy method which can reduce PTV margins in patients with liver tumors, respiratory motion reduction device (RRD). MATERIALS AND METHODS: For 10 liver cancer patients, the data of internal organ motion were obtained by examining the diaphragm motion under fluoroscope. It was tested for both supine and prone position. A RRD was made using MeV-Green and Styrofoam panels and then applied to the patients. By analyzing the diaphragm movement from patients with RRD, the magnitude of PTV margin was determined and dose volume histogram (DVH) was computed using AcQ-Plan, a treatment planning software. Dose to normal tissue between patients with RRD and without RRD was analyzed by comparing the fraction of the normal liver receiving to 50% of the isocenter dose. DVH and NTCP for normal liver and adjacent organs were also evaluated. RESULTS: When patients breathed freely, average movement of diaphragm was 12+/-1.9 mm in prone position in contrast to 16+/-1.9 mm in supine position. In prone position, difference in diaphragm movement with and without RRD was 3+/-0.9 mm and 12 mm, respectively, showing that PTV margins could be reduced to as much as 9 mm. With RRD, volume of the irradiated normal liver reduced up to 22.7% in DVH analysis. CONCLUSION: Internal organ motion due to breathing can be reduced using RRD, which is simple and easy to use in clinical setting. It can reduce the organ motion-related PTV margin, thereby decrease volume of the irradiated normal tissue.
Abdomen ; Carcinoma, Hepatocellular* ; Diaphragm ; Humans ; Liver ; Liver Neoplasms ; Prone Position ; Respiration ; Supine Position ; Thorax

PURPOSE: To assess the locoregional recurrence rate, survival rate and prognostic factors after modified radical mastectomy and postoperative adjuvant radiation therapy with or with chemotherapy in high-risk breast cancer patients. METHODS: Between 1984-1995, 48 patients underwent postoperative irradiation to the regional lymphatics and chest wall due to large tumor size (> or = 5 cm) or small tumor size (<5 cm) with axillary lymph node involvement after modified radical mastectomy. The median age of the patients was 47 years (range, 31-79 years). The clinical tumor size was <2 cm in 1 patient, 2-5 cm in 15 patients, and >5 cm in 32 patients. Thirty two patients had positive axillary lymph nodes. Forty two patients were irradiated to the chest wall and regional lymph node and 6 patients were irradiated in the chest wall only. Radiation dose to the chest wall and regional lymph node was 5040 cGy/28 fraction. The median follow-up time was 61 months. RESULTS: Locoregional recurrence rate was 8% and distant metastatic rate was 14%. The actuarial overall survival rate and disease-free survival rate was 63% and 62% at 5 years, respectively. The median survival time was 67 months. Five-year overall survival rate by the stage is 70% in IIB and 58% in IIIA. The significant prognostic factor for survival on multivariate analysis was the stage. CONCLUSION: Postoperative adjuvant radiation therapy in high-risk breast cancer can reduce the locoregional recurrence rate and increase the survival time by combined chemotherapy. The significant prognostic factor for survival rate was the stage.
Breast Neoplasms* ; Breast* ; Disease-Free Survival ; Drug Therapy ; Follow-Up Studies ; Humans ; Lymph Nodes ; Mastectomy, Modified Radical ; Multivariate Analysis ; Recurrence ; Survival Rate ; Thoracic Wall

PURPOSE: In this retrospective study, we attempted to evaluate the treatment outcome and the prognostic factors of thymoma treated with surgery, radiotherapy and chemotherapy. METHODS AND MATERIALS: Between 1979 and 1998, 55 patients with thymoma were treated at the Seoul National University Hospital. Of these, 11 patients underwent surgery only, 33 patients received postoperative radiotherapy and 11 patients received radiotherapy only. Twenty-three patients had gross total resection and 21 patients subtotal resection. For postoperative radiotherapy, the radiation dose consisted of 41.4-55.8 Gy. The average follow-up was 64 months, and ranged from 2 to 160 months. The sex ratio was 1:1 and the median age was 48 years (15-74 years). Overall survival and disease-free survival were determined via the Kaplan-Meier method, and the log-rank was employed to evaluate for differences in prognostic factor. RESULTS: The five- and 10-year survival rates were 87% and 65% respectively, and the median survival was 103 months. By univariate analysis, only stage ( p=0.0017) turned out to be significant prognostic factors of overall survival. Also, stage ( p=0.0007) was significantly predictive for overall survival in mutivariated analysis. CONCLUSION: This study showed the stage was found to be important prognostic factors, which influenced survival. Especially, as incomplete resection is related with poor results, complete resection is important to cure the invasive thymoma.
Disease-Free Survival ; Drug Therapy ; Follow-Up Studies ; Humans ; Radiotherapy ; Retrospective Studies ; Seoul ; Sex Ratio ; Survival Rate ; Thymoma* ; Treatment Outcome*

PURPOSE: This study was performed for the evaluation of the feasibility and toxicity of hypofractionated radiation therapy for early glottic cancer METHODS AND MATERIALS: From February 1999 to February 2000, 20 patients with histologically confirmed Stage I, II glottic cancer were enrolled into this study. There were 18 males and 2 females, the median age of the patients was 59 years. The distribution of stage distribution was as follows; T1aN0-16 patients, T1bN0-1 patient, T2N0-3 patients. Eighteen patients underwent laryngomicroscopic biopsy only, and two patients underwent laser cordectomy. All patients received radical radiation therapy (2.5 Gy per fraction, 24 fractions, total 60 Gy). Median duration of treatment was 36 days (range 31-45 days). RESULTS: Radiation therapy were well tolerated. Most common acute reactions were odynophagia and hoarseness, and these reactions resolved after radiation therapy. There were one case of RTOG grade 3 odynophagia (5%), six cases of grade 3 hoarseness (30%). Response of radiation therapy was evaluated one month after completion of treatment. All patients revealed complete response. During follow up, total three cases of treatment failure were detected. two cases were local recurrence in 10 and 13 months of radiation therapy and one case was local recurrence and distant metastasis in 2 months of radiation therapy CONCLUSION: This hypofractionated radiation therapy schedule was feasible and effective for control of early glottic cancer. But longer follow up time would be required to assess the long-term disease control and the late complication by shortening radiation therapy duration.
Appointments and Schedules ; Biopsy ; Female ; Follow-Up Studies ; Hoarseness ; Humans ; Male ; Neoplasm Metastasis ; Recurrence ; Treatment Failure

PURPOSE: The target volume for the three field technique in breast cancer include the breast tangential and supraclavicular areas. The techniques rotating the gantry and couch angles, to match these two areas, will geometrically produce mismatching of the posterior edge between the medial and lateral tangential beams. This mismatch was confirmed by film dosimetry and three-dimensional computer planning. The correction methods of this mismatching were studied in this article. MATERIALS AND METHODS: After the supraclavicular field was simulated using a half beam block and the medial and lateral tangential fields, by the rotation of the couch and gantry, we compared the following two methods to correct the mismatch. The first method was the rotation of collimator until a line drawn on the posterior edge of tangential beams before the rotation of couch aligned the line drawn on the posterior edge after the rotation. The second method was the rotation of collimator according to the formula developed by the author as follows; Co=2sin(-1){sin angle x sin (C/2)} (Co: collimator angle, angle: angle between tangential beam and table, C: couch angle) RESULTS: The film dosimetry showed the mismatching of posterior edges of the medial and lateral tangential fields prior to the rotation of collimator, while the posterior edges matched well after the rotation of collimator according to the formula. The three-dimensional computer plan also showed that the posterior edges matched well after the rotation of collimator accordingly. The DVH of the ipsilateral lung with the proper rotation of collimator angle was better than that without the rotation of collimator angle. CONCLUSION: The mismatching of the posterior edges of the medial and lateral tangential fields can be recognized on the three field technique in breast irradiation when the gantry and couch are simultaneously rotated and can be corrected with the proper rotation of the collimator angle. The radiation dose to the ipsilateral lung could be lowered with this technique.
Breast Neoplasms* ; Breast* ; Film Dosimetry ; Lung

PURPOSE: The purpose of this study was to evaluate whether a GafChromic film applied to stereotactic radiosurgery with a linear accelerator could provide information on the value for acceptance testing and quality control on the absolute dose and relative dose measurements and/or calculation of treatment planning system. MATERIALS AND METHODS: A spherical acrylic phantom, simulating a patient's head, was constructed from three points. The absolute and relative dose distributions could be measured by inserting a GafChromic film into the phantom. We tested the use of a calibrated GafChromic film (MD-55-2, Nuclear Associate, USA) for measuring the optical density. These measurements were achieved by irradiating the films with a dose of 0-112 Gy employing 6 MV photon. To verify the accuracy of the prescribed dose delivery to a target isocenter using a five arc beams (irradiated in 3 Gy per one beam) setup, calculated by the Linapel planning system the absolute dose and relative dose distribution using a GafChromic film were measured. All the irradiated films were digitized with a Lumiscan 75 laser digitizer and processed with the RIT113 film dosimetry system. RESULTS: We verified the linearity of the Optical Density of a MD-55-2 GafChromic film, and measured the depth dose profile of the beam. The absolute dose delivered to the target was close to the prescribed dose of Linapel within an accuracy for the GafChromic film dosimetry (of +/- 3%), with a measurement uncertainty of +/- 1 mm for the 50~90% isodose lines. CONCLUSION: Our results have shown that the absolute dose and relative dose distribution curves obtained from a GafChromic film can provide information on the value for acceptance. To conclude the GafChromic film is a convenient and useful dosimetry tool for linac based radiosurgery.
Film Dosimetry* ; Head ; Particle Accelerators* ; Quality Control ; Radiosurgery* ; Uncertainty

PURPOSE: To propose a conceptual design of a novel source for intensity modulated brachytherapy. MATERIALS AND METHODS: The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a 90Sr/Y Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quater of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. RESULTS: The preliminary hypothetical simulation and optimization results demonstrated the 87% difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7% by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. CONCLUSION: The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter.
Brachytherapy* ; Catheters ; Feasibility Studies* ; Steel

PURPOSE: Oral mucositis is a common toxicity of radiation or chemotherapy, which is used a treatment for head and neck cancer. We investigated effects of recombinant human epidermal growth factor (rhEGF) on radiation-induced oral mucositis in rat model. MATERIALS AND METHODS: Spraque-Dawley rats (7 per group) exposed to a single dose of 25 Gy (day 0) on their head, except for one group, were randomly divided into un-treated, vehicle-treated, and two rhEGF- treated groups. Rats were topically applied with rhEGF (15 or 30 microgram/oral cavity/day) or vehicle to their oral mucosa. Survival rate of rats, weight changes, and food intakes were examined from day 0 to 18 after radiation. Histology study was performed from oral mucosa of rats at day 7 and 18 after radiation. RESULTS: rhEGF-treated groups (15 or 30 microgram/day) showed all survival rate 33%, whereas un-treated and vehicle-treated groups showed all survival rate 0% at the end of experiment. rhEGF-treated groups statistically had less weight loss compared to vehicle-treated group from day 2 to 7 after radiation. Food intake of rats with rhEGF treatment turned to increase at day 14 after radiation. At 7 day after radiation, un-treated and vehicle-treated groups showed severe pseudomembraneous or ulcerative oral mucositis. On the other hand, rhEGF-treated groups had no more than cellular swelling and degeneration of epidermal cells in oral mucosa of rats. CONCLUSION: These results suggest that rhEGF has significantly positive effects on radiation-induced oral mucositis in rats. rhEGF display a therapeutic potential on a clinical level.
Animals ; Drug Therapy ; Eating ; Epidermal Growth Factor* ; Hand ; Head ; Head and Neck Neoplasms ; Humans* ; Models, Animal ; Mouth Mucosa ; Rats* ; Stomatitis* ; Survival Rate ; Ulcer ; Weight Loss

PURPOSE: Renal irradiation can lead to the development of radiation nephropathy, and this is characterized by the accumulation of extracellular matrix and final fibrosis. To determine the possible role of the glomerular epithelial cell, the radiation-induced changes in the expression of its genes associated with the extracellular matrix were analyzed. MATERIALS AND METHODS: Rat glomerular epithelial cells (GEpC) were irradiated with a single dose of 0, 2, 5, 10 and 20 Gy with using 6 MV LINAC (Siemens, USA), and the samples were collected 6, 24, 48 and 72 hours post-irradiation, respectively. Northern blotting, western blotting and zymography were used to measure the expression level of fibronectin (Fn), plasminogen activator inhibitor-1 (Pai-1), matrix metalloproteinases-2, 9 (MMP-2, 9), tissue inhibitor of metalloproteinase-2 (TIMP-2), tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA). RESULTS: Irradiation with a single dose of 10 Gy resulted in a significant increase in Fn mRNA since 24 hours post-irradiation, and a single dose of 5 and 10 Gy significantly increased the Fn immunoreactive protein measured 48 hours post-irradiation. An increase in Pai-1 mRNA and protein was also observed and especially, a single dose of 10 Gy significantly increased the mRNA measured 24 and 48 hours post-irradiation. The active MMP-2 measured 24 hours post-irradiation slightly increased in a dose dependent manner, but this increase did not reach statistical significance. The levels of MMP-9, TIMP-2, t-PA and u-PA appeared unaltered after irradiation. CONCLUSION: Irradiation of the glomerular epithelial cells altered the expression of genes associated with the extracellular matrix, implying that the glomerular epithelial cell may be involved in the development of radiation nephropathy.
Animals ; Blotting, Northern ; Blotting, Western ; Epithelial Cells* ; Extracellular Matrix ; Fibronectins* ; Fibrosis ; Plasminogen Activator Inhibitor 1* ; Plasminogen Activators ; Rats* ; RNA, Messenger ; Tissue Inhibitor of Metalloproteinase-2 ; Tissue Plasminogen Activator ; Urokinase-Type Plasminogen Activator

PURPOSE: We examined whether intratumoral (i.t.) administration of dendritic cells (DCs) into a treated tumor could induce local and systemic antitumor effects in a mouse tumor model. METHODS AND MATERIALS: C57BL/6 mice were inoculated s.c. in the right and left thighs with MCA-102 fibrosarcoma cells on day 0 and on day 7, respectively. On day 7, the tumors (usually 6 mm in diameter) on the right thigh were heated by immersing the tumor-bearing leg in a circulating water bath at 43 degrees C for 30 min; thereafter, the immature DCs were i.t administered to the right thigh tumors. This immunization procedure was repeated on days 7, 14 and 21. The tumors in both the right and left thighs were measured every 7 days and the average sizes were determined by applying the following formula, tumor size=0.5 x (length+width). Cytotoxicity assay was done to determine tumor-specific cytotoxic T-lymphocyte activity. RESULTS: Hyperthermia induced apoptosis and heat shock proteins (HSPs) in tumor occurred maximally after 6 hr. For the local treated tumor, hyperthermia (HT) alone inhibited tumor growth compared with the untreated tumors (p<0.05), and furthermore, the i.t. administered DCs combined with hyperthermia (HT+DCs) additively inhibited tumor growth compared with HT alone (p<0.05). On the distant untreated tumor, HT alone significantly inhibited tumor growth (p<0.05), and also HT+DCs potently inhibited tumor growth (p<0.001); however, compared with HT alone, the difference was not statistically significant. In addition, HT+DCs induced strong cytotoxicity of the splenocytes against tumor cells compared to DCs or HT alone. CONCLUSION: HT+DCs induced apoptosis and increased the expression of HSPs, and so this induced a potent local and systemic antitumor response in tumor-bearing mice. This regimen may be beneficial for the treatment of human cancers.
Animals ; Apoptosis ; Baths ; Dendritic Cells* ; Fever* ; Fibrosarcoma ; Heat-Shock Proteins ; Hot Temperature ; Humans ; Immunization ; Leg ; Methods ; Mice ; T-Lymphocytes, Cytotoxic ; Thigh ; Water