Secondary exposure for 73 and 200 MeV proton therapy.
Following modifications on the beam line at the Orsay Protontherapy Center, dose measurements were performed in order to make a dose map in the treatment rooms and in the delimited radiation-controlled area around beam line. Measurements were performed using tissue-equivalent proportional counters and rem-counters. Analysis of TEPC single event measurements showed that high LET components (>10 keV.microm(-1)) represent 90 to 99% of total dose equivalent in the treatment rooms and 50 to 90% in the controlled area and quality factors range, respectively between 2 and 15. A fast neutron component was identified in the treatment rooms, where dose equivalent rate varied between few microSv.h(-1) to some dozen of mSv.h(-1). In high-energy radiation field rem-counters underestimated TEPC values for neutron component. The variation between instruments response according to the location is linked to energetic spectrum variations and instrument characteristics.
Trompier
F
F
Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP 17, F-92262 Fontenay-aux-Roses Cedex, France. francois.trompier@irsn.fr
Delacroix
S
S
Vabre
I
I
Joussard
F
F
Proust
J
J
D004781:Environmental Exposure / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D038622:Internationality; D061766:Proton Therapy; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000295:instrumentation* / Q000379:methods*; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods*; D011882:Radiotherapy, High-Energy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011522:Protons
D011522:Protons