Related Experiment Video
Updated: Oct 17, 2026
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
The use of high density metal foils to increase surface dose in low-energy clinical electron beams
G D Lambert1, N D Richmond, R H Kermode
1Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne, Tyne and Wear, UK.
Background And Purpose:
This paper describes a practical method of elevating the surface dose of clinical electron beams in the energy range 3-12 MeV using thin high density metal foils (tin and lead) as an alternative to tissue equivalent bolus. Because, relative to water, these materials exhibit a high scattering power to stopping power ratio, the desired dose elevation may be achieved with less energy loss than conventional bolus and consequently a gain in therapeutic interval.
Methods:
The foil thickness required to raise the surface dose to 90% off peak, for a given electron energy, was calculated using published scattering and stopping power data. An empirical expression is derived to facilitate calculation of foil thickness (tin or lead) to produce a given surface dose.
Results And Conclusions:
Measurements were made to confirm the predictions of the derived expression and were found to be in good agreement.
