PURPOSE: The aim of this study was to evaluate the clinical results of postoperative radiotherapy for parotid gland malignancy, and determine prognostic factors for locoregional control and survival. MATERIALS AND METHODS: Between 1980 and 2002, 130 patients with parotid malignancy were registered in the database of the Department of Radiation Oncology, Seoul National University Hospital. The subjects of this analysis were...

PURPOSE: To analyze the outcome of radiation therapy for patients with a metastatic carcinoma of cervical lymph nodes from an unknown primary (MUO), and identify the prognostic factors for these patients. MATERIALS AND METHODS: Between July 1981 and June 1999, 39 patients with MUO underwent radiation therapy with curative intent. Twelve patients were treated with radiation therapy alone (Group 1), 8...

BACKGROUND: The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy...

PURPOSE: To investigate the effect of low dose radiation on neuronal cell proliferation in diabetic rats. MATERIALS AND METHODS: A group of rats (first group) were divided into three subgroups (nondiabetic control, nondiabetic 0.1 Gy and nondiabetic 10 Gy groups) to determine the effect of radiation on normal hippocampal neuronal cell proliferation. A further group of rats (second group) were divided...

PURPOSE: The changed expressions of TGF-beta1, as a key cytokine in the fibrotic process, due to melatonin with potent antioxidative effects, were investigated in the irradiated lung using fibrosis-sensitive C57BL/6 mice. MATERIALS AND METHODS: Female C57BL/6 mice were divided into control irradiation-only, and melatonin (300 mg/kg i.p. 1 hr before irradiation) pretreatment groups. The thoraces of the mice were irradiated with...

PURPOSE: Although computed tomography (CT) simulators are commonly used in radiation therapy department, many institution still use conventional CT for treatments. In this study the setup errors that occur during simulation, CT scan (diagnostic CT scanner), and treatment were evaluated for the twenty one breast cancer patients. MATERIALS AND METHODS: Errors were determined by calculating the differences in isocenter location, SSD,...

PURPOSE: Film dosimetry as a part of patient specific intensity modulated radiation therapy quality assurance (IMRT QA) was performed to develop a new optimization method of film isocenter offset and to then suggest new quantitative criteria for film dosimetry. MATERIALS AND METHODS: Film dosimetry was performed on 14 IMRT patients with head and neck cancers. An optimization method for obtaining the...

PURPOSE: To improve the management of a medical linear accelerator, the records of operational failures of a Varian CL2100C over a ten year period were retrospectively analyzed. MATERIALS AND METHODS: The failures were classified according to the involved functional subunits, with each class rated into one of three levels depending on the operational conditions. The relationships between the failure rate and...

An ameloblastic carcinoma is a very rare odontogenic malignant tumor, which sometimes have a benign clinical nature, but typically have aggressive features, with large ulcerative lesion and extensive local destruction. These clinical characteristics make the complete surgical removal of a tumor difficult. As a consequence, a poor prognosis may result due to local recurrence and distant metastasis. For this reason,...