The relative biological effectiveness of 160 MeV protons I. Microdosimetry
| Autor: | Yuk-Ming P. Lam, Paul Kliauga, Harald H. Rossi, Robert D. Colvett |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Cancer Research
Radiation Proton business.industry Statistics as Topic Cyclotron Linear energy transfer Radiotherapy Dosage Bragg peak Spectral line law.invention Radiotherapy High-Energy Energy Transfer Oncology law Relative biological effectiveness Slab Dosimetry Medicine Radiology Nuclear Medicine and imaging Protons Atomic physics Nuclear medicine business Relative Biological Effectiveness |
| Zdroj: | International Journal of Radiation Oncology*Biology*Physics. 4:1001-1008 |
| ISSN: | 0360-3016 |
| DOI: | 10.1016/0360-3016(78)90012-3 |
| Popis: | Measurements of the distribution of lineal energy density, the microdosimetric parameter analogous to linear energy transfer (LET), were performed on the 160 MeV proton beam at the Harvard Cyclotron. Measurements at various positions on the extended Bragg peak produced by a beam modulator are compared with each other and with measurements on an unmodulated beam. The results are compared with computer-generated spectra produced by using a simple model to simulate the action of the beam modulator. The spectra are found to be highly sensitive to position at the extreme distal portion of the extended Bragg peak. The effective dose mean lineal energy density (corrected for saturation) increases by ∼ 20% from the front to center of the extended peak region, and increases by a factor of two from center to rear. Thus, relative biological eflectiveness RBE may be a function of position, and biological effects in an extended specimen may be enhanced in a slab a few millimeters thick located at the distal portion of the extended Bragg peak. |
| Databáze: | OpenAIRE |
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