PURPOSE: This study was designed to examine the reliability of the new version of the AJCC staging system (1997) of nasopharyngeal carcinoma in comparison with the AJCC staging system of 1992. MATERIALS AND METHODS: Between 1983 and 1996, 185 patients with histologically proven nasopharyngeal carcinoma were treated with radiation therapy at the Department of Therapeutic Radiology Seoul National University Hospital. For these patients, AJCC staging system of 1992 was compared with the 1997 version, by reviewing hospital records, computed tomography (CT) and/or magnetic resonance imaging (MRI). RESULTS: 5-year overall survival rates according to the 1992 and 1997 AJCC staging systems were 100%, and 100% at stage I; 100%, and 68.8% at stage II; 61.4%, and 63.8% at stage III; 61.1%, and 63.2% at stage IV. 5-year overall survival rates of each classification showed significant differences between stages ( p=0.0049 for the old version, p=0.01 for the new), but no significant difference was found between the staging systems except at stage II. CONCLUSION: The new AJCC staging system allows staging as reliably as the 1992 version, but the adequacy of the newly modified staging classification should be confirmed by further clinical examination.
Classification ; Hospital Records ; Humans ; Magnetic Resonance Imaging ; Radiation Oncology ; Seoul ; Survival Rate

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 outcome and prognostic factors of brainstem glioma were evaluated following radiotherapy methods. MATERIALS AND METHODS: Between 1986 and 2001, 45 childhood patients with diffuse brainstem glioma were treated. There were 26 boys and 19 girls, with a median age of 7 years (range 3~18). The histopathological diagnoses were confirmed in 13 patients, which revealed a low-grade glioma in four patients, and high-grade glioma in the other nine. Before 1993, radiation therapy using a regime of 1.8 to 2.0 Gy once a day was performed in 16 cases; thereafter, a regimes of 1.1 or 1.5 Gy twice a day was given in 15 and 14 cases, respectively. Nine patients were treated with adjuvant chemotherapy. The response to the treatment was evaluated by the MRI findings 4 weeks after radiotherapy. RESULTS: After radiotherapy, the neurological deficit improved in 42 of the 45 patients (93%). The MRI responses were as follows; partial response 22/39 (56%), minimal to no response in 16/39 (41%) and tumor progression in 1/39 (3%). The median time to disease progression was 7 months, and the median survival was 12 months; the overall survival rate at 1 year was 41%. There was no significant prognostic factor for overall survival. The progression-free survival was influenced by the tumor histology (low grade vs. high grade, p=0.05) in those patients whose pathology was confirmed. CONCLUSION: The radiation therapy fractionation schedule did not influence the survival. Low grade histology was a possible favorable prognostic factor of progression-free survival in pediatric brainstem glioma patients.
Appointments and Schedules ; Brain Stem* ; Chemotherapy, Adjuvant ; Diagnosis ; Disease Progression ; Disease-Free Survival ; Female ; Glioma* ; Humans ; Magnetic Resonance Imaging ; Pathology ; Radiotherapy ; Survival Rate

PURPOSE: The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. MATERIALS AND METHODS: Four human cancer cell lines-PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in 25 cm2 flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for 10~14 days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. RESULTS: There was minimal variation in the values gained from these two methods with the standard deviation generally less than 5%, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the R2 value of 0.975~0.992 between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than 30%). For cells with low plating efficiency (less than 30%), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. CONCLUSION: In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.
Cell Count ; Cell Line ; Humans ; Radiation Tolerance* ; Tetrazolium Salts

PURPOSE: Acute leukemia with hyperleukocytosis (more than 105/mm3) is at high risk of early sudden death, usually from intracerebral hemorrhage. Emergency cranial irradiation is a relatively simple approach to solve this the problem. We summarized our experience of cranial irradiation in 24 leukemic children who presented with hyperleukocytosis. METHODS AND MATERIALS: Between 1990 and 1998, 40 children with acute leukemia presenting with hyperleukocytosis were referred for emergency cranial irradiation. Among these patients, 24 children were evaluable. There were 16 boys and eight girls, their ages ranged from 2 to 13 years (median 9.5 years). The initial leukocyte counts ranged 109,910/mm3 to 501,000/mm3. Peripheral blood smear was performed in all patients and noted the morphology of the blast. Introduction of emergency cranial irradiation was determined by the leukocyte counts (more than 100,000/mm) and the existence of the blast in peripheral blood smear. All patients were treated with intravenous hydration with alkaline fluid and oral allopurinol. Cranial irradiation started on the day of diagnosis. With 2 Gy in one fraction in 4 patients, 4 Gy in two fractions in 20 patients. RESULTS: The WBC count had fallen in 19 patients (83%) and no intracerebral hemorrhage occurred after irradiation. There were five cases of early deaths. Four patients died of metabolic complications, and one patient with intracerebral hemorrhage. He died 5 hours after cranial irradiation. No patient had any immediate side effect from cranial irradiation. CONCLUSION: Our data suggest, that emergency cranial irradiation can be safely chosen and effective in childhood leukemic patients presenting with high leukocyte counts.
Allopurinol ; Cerebral Hemorrhage ; Child ; Cranial Irradiation* ; Death, Sudden ; Diagnosis ; Emergencies ; Female ; Humans ; Leukemia ; Leukocyte Count

PURPOSE: To assess the feasibility and the toxicity of the neoadjuvant chemotherapy on the treatment of patients with locoregionally advanced nasopharyngeal carcinoma. MATERIALS AND METHODS: We analyzed 77 previouly untreated and histologically confirmed advanced stage nasopharyngeal carcinoma patients treated with neoadjuvant chemotherapy followed by radiation therapy at the Seoul National University Hospital between 1984 and 1996. The stage distribution was therapy at the Seoul National University Hospital between 1984 and 1996. The stage distribution was as follows : AJCC stage III-2, stage IV-75, Sixty-six patients received infusion of 5-FU (1000 mg/m2, on Day 1~5) and cisplatin (100 mg/m2, on Day 1), eleven patients received infusion of 5-FU (1000 mg/m2, on Day 1~5) and carboplatin (300 mg/m2, on Day 1), as neoadjuvant chemotherapy prior to radiation therapy. The median follow-up for surviving patients was 44 months. RESULTS: The overall chemotherapy response rates were 87%. The toxicities of chemotherapy were mild. Only 3 patients experienced Grade 3 toxicities (1 for cytopenia, 2 for nausea/vomiting). The degree of radiation induced mucositis was not severe, and then patients developed Grade 2 mucositis. The 5-year overall survival rates were 68% and the 5-year disease free survival rates were 65%. The 5-year overall survival rates were 68% and the 5-year disease free survival rates were 65%. The 5-year freedom from distant metastasis rates were 82% and 5-year locoregional control rates were 75%. CONCLUSION: This single institution experience suggests that neoadjuvant chemotherapy improves overall survival and disease free survival for patients with advanced stage nasopharyngeal carcinoma without increase of toxicity.
Carboplatin ; Cisplatin ; Disease-Free Survival ; Drug Therapy* ; Fluorouracil ; Follow-Up Studies ; Freedom ; Humans ; Mucositis ; Neoplasm Metastasis ; Seoul ; Survival Rate

Ependymoma can spread via cerebrospinal fluid, but late spinal recurrences of intracranial tumor are very rare. We describe a case of a 33-year-old male who presented with multiple, delayed, recurrent lesions in the spinal cord from an intracranial ependymoma. The patient underwent gross total resection and postoperative radiation therapy 14 years prior to visit for a low grade ependymoma in the 4th ventricle. The large thoraco-lumbar intradural-extramedullary spinal cord tumor was surgically removed and the pathologic diagnosis was an anaplastic ependymoma. An adjuvant whole-spine radiation therapy for residual spine lesions was performed. After completion of radiation therapy, a MRI showed a near complete response and the disease was stable for three years.
Adult ; Cerebrospinal Fluid ; Diagnosis ; Ependymoma* ; Humans ; Magnetic Resonance Imaging ; Male ; Recurrence* ; Spinal Cord Neoplasms ; Spinal Cord* ; Spine

In this study, we investigated the effect of time gating threshold on the delivered dose at a organ with internal motion by respiration. Generally, the internal organs have minimum motion at exhalation during normal breathing. Therefore to compare the dose distribution time gating threshold, in this paper, was determined as the moving region of target during 1 sec at the initial position of exhalation. The irradiated fields were then delivered under three conditions; 1) non-moving target 2) existence of the moving target in the region of threshold (1sec), 3) existence of the moving target region out of threshold (1.4 sec, 2 sec). And each of conditions was described by the moving phantom system. It was compared with the dose distributions of three conditions using film dosimetry. Although the treatment time increased when the dose distributions was obtained by the internal motion to consider the TGT, it could be obtained more exact dose distribution than in the treatment field that didn't consider the internal motion. And it could be reduced the unnecessary dose at the penumbra region. When we set up 1.4 sec of threshold, to reduce the treatment time, it could not be obtained less effective dose distribution than 1 sec of threshold. Namely, although the treatment time reduce, the much dose was distributed out of the treatment region. Actually when it is treated the moving organ, it would rather measure internal motion and external motion of the moving organ than mathematical method. If it could be analyzed the correlation of the internal and external motion, the treatment scores would be improved.
Exhalation ; Film Dosimetry ; Respiration*

PURPOSE: To establish the role of stereotactic radiosurgery using a linear accelerator for the treatment of patients with cavernous angioma. MATERIALS AND METHODS: Between February 1995 and May 1997, 11 patients with cavernous angioma were treated with stereotactic radiosurgery using a linear accelerator. Diagnoses were based on the magnetic resonance imaging in 8 patients, and the histological in 3. The vascular lesions were located in the brainstem (5 cases), cerebellum (2 cases) thalamus (1 case) and cerebrum (3 cases). The clinical presentation at onset included previous intracerebral hemorrhages (9 cases) and seizures (2 cases). All patients were treated with a a linac-based radiosurgery. The median dose of radiation delivered was 16 Gy ranging from 14 to 24 Gy, which was typically prescribed to the 80% isodose surface (range 50~80%), corresponding to the periphery of the lesion with a single isocenter. Ten patients were followed-up. RESULTS: The median follow-up was 49 months ranging from 8 to 73 months, during which time two patients developed an intracerebral hemorrhage, 1 at 8 months, with the other at 64 months post radiosurgery. One patient developed neurological deficit after radiosurgery, and two developed an edema on the T2 weighted images of the MRI surrounding the radiosurgical target. CONCLUSION: The use of stereotactic radiosurgery in the treatment of a cavernous angioma may be effective in the prevention of rebleeding, and can be safely delivered. However, a longer follow-up period will be required.
Brain Stem ; Cerebellum ; Cerebral Hemorrhage ; Cerebrum ; Diagnosis ; Edema ; Follow-Up Studies ; Hemangioma, Cavernous* ; Humans ; Magnetic Resonance Imaging ; Particle Accelerators ; Radiosurgery* ; Seizures ; Thalamus

Based on the assumption that apparent diffusion coefficients (ADCs) define high-risk clinical target volume (aCTVHR) in high-grade glioma in a cellularity-dependent manner, the dosimetric effects of aCTVHR-targeted dose optimization were evaluated in two intensity-modulated radiation therapy (IMRT) plans. Diffusion-weighted magnetic resonance (MR) images and ADC maps were analyzed qualitatively and quantitatively to determine aCTVHR in a high-grade glioma with high cellularity. After confirming tumor malignancy using the average and minimum ADCs and ADC ratios, the aCTVHR with double- or triple-restricted water diffusion was defined on computed tomography images through image registration. Doses to the aCTVHR and CTV defined on T1-weighted MR images were optimized using a simultaneous integrated boost technique. The dosimetric benefits for CTVs and organs at risk (OARs) were compared using dose volume histograms and various biophysical indices in an ADC map-based IMRT (IMRTADC) plan and a conventional IMRT (IMRTconv) plan. The IMRTADC plan improved dose conformity up to 15 times, compared to the IMRTconv plan. It reduced the equivalent uniform doses in the visual system and brain stem by more than 10% and 16%, respectively. The ADC-based target differentiation and dose optimization may facilitate conformal dose distribution to the aCTVHR and OAR sparing in an IMRT plan.
Contrast Media ; Gadolinium ; Glioma/*radiotherapy ; Humans ; Magnetic Resonance Imaging/*methods ; *Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted/*methods ; Radiotherapy, Intensity-Modulated/*methods ; Tumor Burden