60 research outputs found
Treatment planning for the layer-stacking irradiation system for three-dimensional conformal heavy-ion radiotherapy
We have upgraded a heavy-ion radiotherapy treatment-planning system to adapt for the layer-stacking irradiation method, which is to conform a variable spread-out Bragg peak to a target volume by means of dynamic control of the conventional beam-modifying devices. The biophysical model, the beam-setup logic, and the dose-calculation algorithm implemented for the layer-stacking method are described and the expected clinical usability is discussed. The layer-stacking method was integrated in perfect accordance with the ongoing conventional treatments so that the established protocols, which are the clinically optimized dose fractionation schemes, will still be valid. On the other hand, a simulation study indicated a substantial improvement of dose distribution with the layer-stacking method though the significance may depend on the size, shape, and location of the tumor. The completed treatment system will provide an option for improved conformal radiotherapy without interfering with the conventional method and we expect a gradual expansion of the clinical cases applicable to the layer-stacking method
Type Ibn Supernovae Show Photometric Homogeneity and Spectral Diversity at Maximum Light
Measurement of the multihadron production cross section from electron-positron annihilation using the VENUS detector at TRISTAN
Structure of dimerized radixin FERM domain suggests a novel masking motif in C-terminal residues 295–304
The crystal structure of dimerized radixin FERM domain has been determined. It was found that the adhesion molecule-binding site of one molecule is masked by the C-terminal residues of the other molecule
Commisioning of Conformal Heavy-Ion Radiotherapy with the Layer-Stacking Method
8th Workshop on Heavy Charged Particles in Biology and Medicin
Experimental evaluation of analytical penumbra calculation model for wobbled beams
The goal of radiotherapy is not only to apply a high radiation dose to a tumor, but also to avoid side effects in the surrounding healthy tissue. Therefore, it is important for carbon-ion treatment planning to calculate accurately the effects of the lateral penumbra. In this article, for wobbled beams under various irradiation conditions, we focus on the lateral penumbras at several aperture positions of one side leaf of the multileaf collimator. The penumbras predicted by an analytical penumbra calculation model were compared with the measured results. The results calculated by the model for various conditions agreed well with the experimental ones. In conclusion, we found that the analytical penumbra calculation model could predict accurately the measured results for wobbled beams and it was useful for carbon-ion treatment planning to apply the model
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