Use of an electron spoiler for radiation treatment of surface skin diseases.
OBJECTIVE
Low-energy electron beams are characterised by low surface doses with a pronounced dose build-up and penetration of several centimetres, but often a higher surface dose and a lower penetration range is desired. The purpose of this study was to investigate the use of an electron spoiler to modify these beams for treating surface skin diseases and evaluate the feasibility of this method.


METHODS
An aluminium foil 4-mm thick covering the end of the electron applicator was used as a spoiler for a 6 MeV electron beam. The dosimetric characteristics of this beam were measured, and Monte Carlo simulations were performed.


RESULTS
The spoiler reduced the practical range and increased surface and build-up doses, but it also significantly broadened the penumbra and increased peripheral doses. Nevertheless, the beam was clinically acceptable when skin collimation with lead was employed. Monte Carlo simulations agreed well with all the experimental measurements.


CONCLUSIONS
The feasibility of using a low-energy electron beam with a spoiler for treating surface skin diseases was demonstrated. The method is hygienic and avoids some of the disadvantages associated with the bolus technique, but it is valid only for flat surfaces and perpendicular incidence. As a consequence, it can be an alternative to bolus and other reported methods in certain cases, especially when a particular sterility assurance level is required.
Hernández
Víctor
V
Department of Medical Physics, Hospital Universitari Sant Joan de Reus, IISPV, Tarragona, Spain. vhernandezmasgrau@gmail.com
Sánchez-Reyes
Alberto
A
Badal
Andreu
A
Vila
Antoni
A
Mur
Encarna
E
Pedro
Agustí
A
Sanchiz
Francisco
F
D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D004583:Electrons / Q000627:therapeutic use; D005240:Feasibility Studies; D006801:Humans; D007101:Immersion; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods; D011874:Radiometry; D011878:Radiotherapy / Q000295:instrumentation* / Q000379:methods; D012871:Skin Diseases / Q000532:radiotherapy*; D014867:Water
D014867:Water
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