The use of carbon-loaded thermoluminescent dosimeters for the measurement of surface doses in megavoltage x-ray beams.
To determine the absorbed dose to the skin of patients undergoing radiotherapy with megavoltage radiations, it is necessary for the dose to be measured at shallow depths. This report assesses the suitability of carbon-loaded thermoluminescent dosimeters (manufactured by Vinten Instruments Limited) for this purpose. Measurements have been made of the effective measurement depth of the dosimeters, the linearity with dose, and the variation of sensitivity within a batch. The variation of surface dose with incident angle of radiation for 5-MV x rays has been measured using these disks; the results are compared with results obtained using a thin-windowed ionization chamber.
Thomas
S J
SJ
Medical Physics Department, Addenbrooke's Hospital, Cambidge, United Kingdom.
Palmer
N
N
D006801:Humans; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation*