Acta oncologica
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This synthesis of the literature on radiotherapy for brain tumors, ie, cancer originating in the central nervous system (CNS), is based on 81 scientific articles, including 25 randomized studies, 13 prospective studies, and 25 retrospective studies. These studies involve 11,081 patients. A more comprehensive chapter on brain tumors may be ordered from SBU. ⋯ Life may be extended in this group, otherwise radiotherapy does not influence survival. Stereotactic radiotherapy of solitary, mainly spherical metastases in the brain is often superior to other known methods with respect to palliation and survival. The number of patients is, however, relatively small.
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Comparative Study
A Monte-Carlo program converting activity distributions to absorbed dose distributions in a radionuclide treatment planning system.
In systemic radiation therapy, the absorbed dose distribution must be calculated from the individual activity distribution. A computer code has been developed for the conversion of an arbitrary activity distribution to a 3-D absorbed dose distribution. The activity distribution can be described either analytically or as a voxel based distribution, which comes from a SPECT acquisition. ⋯ Absorbed fractions for photons and electrons in spheres (masses between 1 g and 200 kg) are within 10-15% of those published. Radial absorbed dose distributions in a necrotic tumor show good agreement with published data. The application of the code in a radionuclide therapy dose planning system, based on quantitative SPECT, is discussed.
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A prospective survey was conducted of patients who began radiotherapy in Sweden during 12 weeks in the autumn of 1992. All hospitals that provided radiotherapy participated. The goal was to study the most common diagnoses, corresponding to approximately 80% of the patients. ⋯ They received an average of four treatments, three for those who also received external radiotherapy. The number of brachytherapy treatments varied widely by department. This can be explained by two different therapeutic traditions: one tradition uses agents with low radiation intensity per time unit, resulting in fewer and longer treatments, and the second tradition involves agents with high radiation intensity per time unit, resulting in more, although shorter, treatments.