Secondary exposure for 73 and 200 MeV proton therapy

Radiat Prot Dosimetry. 2007;125(1-4):349-54. doi: 10.1093/rpd/ncm154. Epub 2007 Mar 3.

Abstract

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.

MeSH terms

  • Environmental Exposure / analysis*
  • Equipment Design
  • Equipment Failure Analysis
  • Internationality
  • Proton Therapy*
  • Radiation Dosage
  • Radiation Monitoring / instrumentation*
  • Radiation Monitoring / methods*
  • Radiation Protection / instrumentation*
  • Radiation Protection / methods*
  • Radiotherapy, High-Energy*
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Protons