ABSTRACT
PURPOSE: A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 3D dose distributions. MATERIALS AND METHODS: Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dose- volume histogram. RESULTS: The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a 200x200 (mm2) plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were 4.5~9.0% smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed 1~5% discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. CONCLUSION: This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.
Subject(s)
Anisotropy , Axis, Cervical Vertebra , Benchmarking , BrachytherapyABSTRACT
The application of arthroscopic surgery in wrist is not widely advocated because of technical difficulty. We analysed 11(10 patients) wrists of which were performed arthroscopic synovectomy in wrist from July 1991 to September 1992 in Kyung Hee University Hospital. The age of the patients ranged from 23 to 55 years old. Follow up period was from 12 months to 26 months. The application for the arthroscopic synovectomy in that group of patients were based on such disabling clinical symptoms as severe pain, swelling, limitation of range of motion and roentgenographic type from mild to severe stage. Postoperative diagnosis was histologically confirmed with rheumatoid arthritis in nine wrists (nine patients) and gout in two wrists (one patient). The results were assessed subjectively and objectively with pain, swelling and range of motion. Satisfactory overall results were obtained and there were no complications. Conclusively, arthroscopic synovectomy in the wrist is effective produce to relieve pain of the rheumatoid arthritis and gout but arthroscopic synovectomy of wrist is technically demanded.
Subject(s)
Humans , Arthritis, Rheumatoid , Arthroscopy , Diagnosis , Follow-Up Studies , Gout , Range of Motion, Articular , WristABSTRACT
Tumors of the sacrum are relatively uncommon. The diagnosis is difficult, especially in the early phase of the disease, because the clinical manifestations are nonspecific, the clinical signs may be vague and the radiologic changes are needed to differentiate from intestinal gas shadow. The clinical features are sacral pain, sensory change on perineum, urination difficulty, constipation, and sciatica. Seven cases of sacral tumor were treated at the Department of Orthopaedic Surgery, Kyung Hee University, from October 1981 to October 1992, and the results were as follows: 1. Because of the variability of the sacral tumor, we cannot define the most common tumor. 2. There is difficult in early diagnosis of the tumor, because the symptoms of tumor are similar to that of lumbar disc herniation and the radiologic findings are subtle. 3. CT and MRI are very effective methods to detect the tumor in the sacrum. 4. Curettage, excision, resection, sacrectomy and internal fixation were done according to the kinds of tumors and the amount of bony destruction.