Real-time proton beam range monitoring by means of prompt-gamma detection with a collimated camera

Phys Med Biol. 2014 Mar 7;59(5):1327-38. doi: 10.1088/0031-9155/59/5/1327. Epub 2014 Feb 20.


Prompt-gamma profile was measured at WPE-Essen using 160 MeV protons impinging a movable PMMA target. A single collimated detector was used with time-of-flight (TOF) to reduce the background due to neutrons. The target entrance rise and the Bragg peak falloff retrieval precision was determined as a function of incident proton number by a fitting procedure using independent data sets. Assuming improved sensitivity of this camera design by using a greater number of detectors, retrieval precisions of 1 to 2 mm (rms) are expected for a clinical pencil beam. TOF improves the contrast-to-noise ratio and the performance of the method significantly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Systems
  • Equipment Design
  • Equipment Failure Analysis
  • Gamma Cameras*
  • Gamma Rays
  • Proton Therapy
  • Radiometry / instrumentation*
  • Radiotherapy, Computer-Assisted / instrumentation*
  • Radiotherapy, High-Energy / instrumentation*


  • Protons