Matching of adjacent radiation beams for isocentric qadiotherapy
| Autor: | Casebow Mp |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
medicine.medical_treatment
Posture Breast Neoplasms Radiation Gantry angle law.invention Optics law medicine Humans Radiology Nuclear Medicine and imaging Cerebellar Neoplasms Physics Radiotherapy business.industry Single beam Collimator General Medicine Models Theoretical Radiation therapy Beam shaping Female business Nuclear medicine Beam (structure) Mathematics Medulloblastoma |
| Zdroj: | The British journal of radiology. 57(680) |
| ISSN: | 0007-1285 |
| Popis: | In radiotherapy, it is sometimes necessary to treat large or awkwardly shaped structures with two or more adjacent radiation beams, rather than a single beam. An even dosage across the junction between two fields may be obtained for all depths if the fields are orientated so that the planes representing their adjacent edges (e.g., the 50% decrement) are made to coincide. Half-beam lead blocks have been used in this way to match orthogonal fields, where the beam edges are butted together in a vertical “match plane” (Williamson, 1979). Unfortunately half-beam blocks reduce the length of the fields available, and moreover, as they cover a large area they must either be heavy or allow a substantial penetration of the beam. Some radiotherapy machines allow one collimator block to be moved to the centre to produce this form of treatment. Apart from beam shaping, the half-beam block is used to orientate the beam in a manner additional to that provided by the gantry angle. This effect may, however, be obtained by... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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