Surface dose from megavoltage therapy machines

Journal Article · Mon Dec 01 04:00:00 EST 1975 · Radiology, v. 117, no. 3, pp. 705-708

OSTI ID:4167930

Gagnon, W F; Grant, W III

To determine the cause of increased skin reactions near the edges of the field the authors measured doses at and near the surface of the skin with an extrapolation chamber for the gamma-ray beam of an AECL Eldorado 8 $sup 60$Co $gamma$ irradiator and the x-ray beams of a Varian Clinac 4 linear accelerator, a Varian Clinac 6 linear accelerator, and an ARCO Mevatron 8 linear accelerator. Buildup curves were measured on each machine to locate the depth of the maximum dose (D/sub max/). The surface dose of the central axis was measured as a function of field size. Off-axis surface doses were measured on the Clinac 4 linear accelerator and on the Eldorado 8 $sup 60$Co $gamma$ therapy unit. No measurable increase in surface dose was found leading the authors to believe that the observed skin reaction in the axilla for the Clinac 4 linear accelerator is due to a combination of increased dose at D/sub max/ from the anterior mantle field and an increase in exit dose from the posterior mantle field when compared to similar treatments for $sup 60$Co $gamma$. (auth)

• Research Organization: Univ. of Texas, Houston
• NSA Number: NSA-33-005759
• OSTI ID: 4167930
• Journal Information: Radiology, v. 117, no. 3, pp. 705-708, Journal Name: Radiology, v. 117, no. 3, pp. 705-708; ISSN RADLA
• Country of Publication: United States
• Language: English

Related Subjects

*PATIENTS-- RADIOTHERAPY
*SKIN-- DEPTH DOSE DISTRIBUTIONS
560151* --Biomedical Sciences
Applied Studies--Radiation Effects--Radiation Effects on Animals--Man
BUILDUP
ENERGY LEVELS
GAMMA SOURCES
LINEAR ACCELERATORS
N48510* --Life Sciences--Radiation Effects on Animals--Man
RADIATION DOSES
X-RAY SOURCES