Tissue-equivalent dosimetry

Average tissue doses to defined respiratory tract regions are calculated, the weighted sum of which provides an equivalent dose to the thoracic or extrathoracic region which is consistent with the ICRP tissue weighted dosimetry system. 

LiF activated with magnesium, copper, and phosphorus (Mg, Cu, P) is a highly sensitive phosphor commonly used for radiation dosimetry nsing the TL technique. It is one of the most studied materials. LiF material has low effective atomic number (Z jf=8.2), which is sufficiently close to that of biological tissue (Z ff=7.4) so as to provide a response, which varies only slightly with photon energy. Thus, it can be considered as tissue equivalent. The preparation of LiF Mg,Cu,P,... 

L-a-alanine, H2NCH(CH3)COOH, is the most commonly used material for ESR dosimetry. Alanine has excellent characteristics for dosimetric purposes in several respects [4] (1) high free radical yield (G-value), (2) short relaxation times so that high microwave power can be applied, (3) linear ESR response with radiation dose up to 5-10" Gy, (4) high stability of the radiation induced free radicals so that the dosimeter can be kept as a document of the radiation dose, (5) tissue equivalence for medical and biological applications, (6) non-destructive read-out of dosimeter so that the dose accumulation at repeated exposures can be monitored. 

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