Lead as surface bolus for high-energy photon and electron therapy

Journal Article · Sat Mar 01 00:00:00 EST 1986 · Med. Phys.; (United States)

DOI:https://doi.org/10.1118/1.595955· OSTI ID:5409050

Moyer, R F; King, G A; Hauser, J F

Dose distributions were evaluated under thin sheet lead used as surface bolus for 4- and 10-MV photons and 6- and 9-MeV electrons using a parallel-plate ion chamber and film. A narrow, significantly low dose region (-17%) was noted for 4-MV photons, whereas a 6% increase in dose was present for 10-MV photons. The dose was elevated 15%-22% near the surface of electron fields with lead bolus, but depth dose relationships were similar to soft-tissue-equivalent (STE) bolus. Investigation of partial-field bolus (2-cm-diam circle) documented reduced doses due to lack of lateral electron equilibrium for 10-MV photons, which was less evident using lead, and large edge effects (up to 30%) for electrons using either lead or STE bolus. Dose distributions on sloped surfaces with electron fields were similar for lead and STE; both require thickness adjustment to achieve a desired effective thickness normal to the surface. Lead bolus has been used successfully in clinical practice for photons.

• Research Organization: Reading Hospital and Medical Center, PA
• OSTI ID: 5409050
• Journal Information: Med. Phys.; (United States), Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
LEAD
USES
RADIATION DOSE DISTRIBUTIONS
EVALUATION
ELECTRONS
IONIZATION CHAMBERS
PHOTONS
RADIATION DOSES
RADIOTHERAPY
TISSUE-EQUIVALENT MATERIALS
DOSES
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
LEPTONS
MASSLESS PARTICLES
MATERIALS
MEASURING INSTRUMENTS
MEDICINE
METALS
NUCLEAR MEDICINE
RADIATION DETECTORS
RADIOLOGY
THERAPY
655003* - Medical Physics- Dosimetry