Details

Autor(en) / Beteiligte

• Reft, Chester S.

Titel

The energy dependence and dose response of a commercial optically stimulated luminescent detector for kilovoltage photon, megavoltage photon, and electron, proton, and carbon beams

Ist Teil von

• Medical physics (Lancaster), 2009-05, Vol.36 (5), p.1690-1699

Ort / Verlag

United States: American Association of Physicists in Medicine

Erscheinungsjahr

2009

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Optically stimulated luminescent detectors, which are widely used in radiation protection, offer a number of potential advantages for application in radiation therapy dosimetry. Their introduction into this field has been somewhat hampered by the lack of information on their radiation response in megavoltage beams. Here the response of a commercially available optically stimulated luminescent detector (OSLD) is determined as a function of energy, absorbed dose to water, and linear energy transfer (LET). The detector response was measured as a function of energy for absorbed doses from 0.5 to 4.0 Gy over the following ranges: 125 kVp to18 MV for photons, 6–20 MeV for electrons, 50–250 MeV for protons, and 290 MeV/u for the carbon ions. For the low LET beams, the response of the detector was linear up to 2 Gy with supralinearity occurring at higher absorbed doses. For the kilovoltage photons, the detector response relative to 6 MV increased with decreasing energy due to the higher atomic number of aluminum oxide (11.2) relative to water (7.4). For the megavoltage photons and electrons, the response was independent of energy. The response for protons was also independent of energy, but it was about 6% higher than its response to 6 MV photons. For the carbon ions, the dose response was linear for a given LET from 0.5 to 4.0 Gy, and no supralinearity was observed. However, it did exhibit LET dependence on the response relative to 6 MV photons decreasing from 1.02 at 1.3   keV / μ m to 0.41 at 78   keV / μ m . These results provide additional information on the dosimetric properties for this particular OSL detector and also demonstrate the potential for their use in photon, electron, and proton radiotherapy dosimetry with a more limited use in high LET radiotherapy dosimetry.