PURPOSE: To determine the optimal scheme of postoperative chemoradiotherapy in rectal cancer by comparing survival, patterns of failure, toxicities in early and late radiotherapy groups using a phase III randomized prospective clinical trial. MATERIALS AND METHODS: From January 1996 to March 1999, 307 patients with curatively resected AJCC stage II and III rectal cancer were assigned randomly to an 'early (151...

PURPOSE: Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plans for each site of the brain....

PURPOSE: To clarify the clinical benefit derived from the combined modality therapy (CMT) consisting of chemotherapy (CT) and involved field radiotherapy (RT) for stage I and II angiocentric lymphomas of the head and neck. MATERIALS AND METHODS: Of 143 patients with angiocentric lymphoma of the head and neck treated at our hospital between 1976 and 1995, 104 patients (RT group) received...

PURPOSE: In order to improve dose homogeneity and to reduce acute toxicity in tangential whole breast radiotherapy, we evaluated two treatment techniques using multiple static fields or universal compensators. MATERIALS AND METHODS: 1) Multistatic field technique : Using a three dimensional radiation treatment planning system, Adac Pinnacle 4.0, we accomplished a conventional wedged tangential plan. Examining the isodose distributions, a third...

PURPOSE: This study was undertaken to retrospectively evaluate white blood cell kinetics, especially lymphocyte depression after different treatments, and to find the correlation between immunosuppression and large blood volume and dynamic blood flow within the mediastinal radiotherapy (RT) field in lung cancer. MATERIALS AND METHODS: Thirty-four patients with lung cancer were retrospectively evaluated; 10 patients had only radiotherapy (RT group), 8...

PURPOSE: 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device...

PURPOSE: This study was undertaken to analyze the efficacy and sphincter preservation rate of platinum based neoadjuvant chemotherapy plus radiotherapy versus abdominoperineal resection and postoperative radiotherapy for anal cancer. MATERIALS AND METHODS: Data of forty-two patients with anal cancer were retrospectively analyzed. Among thirty-eight patients with epidermoid histology, four patients received radiotherapy, and nineteen patients received abdominoperineal resection and adjuvant radiotherapy...

This study was done to implement intensity-modulated radiation therapy (IMRT) for the treatment of primary prostate cancer and to compare this technique with conventional treatment methods. A 72-year- old male patient with prostate cancer stage T2a was treated with IMRT delivered with dynamic multi-leaf collimation. Treatment was designed using an inverse planning algorithm, which accepts dose and dose- volume constraints...

PURPOSE: Tumor growth in a given neoplasm is the net result of cell proliferation and cell loss, and apoptosis is the most significant component of continuous cell loss in most tumors. In this study, we examined non-Hodgkin's lymphoma (NHL, n=67) immunohistochemically for the presence of Bcl-2 oncoprotein and P53 protein and compared apoptotic indices (AIs) and Ki-67 proliferative indices (percentages...

PURPOSE: To establish and verify the proper and the practical IMRT (Intensity-modulated radiation therapy) patient QA (Quality Assurance). MATERIALS AND METHODS: An IMRT QA which consists of 3 steps and 16 items were designed and examined the validity of the program by applying to 9 patients, 12 IMRT cases of various sites. The three step QA program consists of RTP related...