External audits of electron beams using mailed TLD dosimetry: preliminary results.
OBJECTIVE
A feasibility study has been performed to investigate the possibility of using mailed thermoluminescence dosimetry (TLD) for external audits of clinical electron beams in Europe.


METHODS
In the frame of the EC Network Project for Quality Assurance in Radiotherapy, instruction sheets and mailing procedures have been defined for mailed TLD dosimetry using the dedicated holder developed by a panel of experts of the International Atomic Energy Agency (IAEA). Three hundred and thirty electron beam set-ups have been checked in the reference centres and some local centres of the EC Network Project and in addition through the centres participating to the EORTC Radiotherapy Group trial 22922.


RESULTS
The mean ratio of measured dose to stated dose is 0.2% and the standard deviation of measured dose to stated dose is 3.2%. In seven beam set-ups, deviations greater than 10% were observed (max. 66%), showing the usefulness of these checks.


CONCLUSIONS
The results of this feasibility study (instruction sheets, mailing procedures, holder) are presently endorsed by the EQUAL-ESTRO structure in order to offer in the future to all ESTRO members the possibility to request external audits of clinical electron beams.
Gomola
I
I
Department of Oncology, Section of Radiation Physics, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
Van Dam
J
J
Isern-Verdum
J
J
Verstraete
J
J
Reymen
R
R
Dutreix
A
A
Davis
B
B
Huyskens
D
D
D003037:Cobalt Radioisotopes; D005060:Europe; D005240:Feasibility Studies; D006801:Humans; D008485:Medical Audit / Q000379:methods*; D011177:Postal Service; D011785:Quality Assurance, Health Care / Q000379:methods; D019275:Radiopharmaceuticals; D011878:Radiotherapy / Q000295:instrumentation / Q000592:standards; D011879:Radiotherapy Dosage; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation
D003037:Cobalt Radioisotopes; D019275:Radiopharmaceuticals