Radiochromic film is investigated for use in dosimetry in water phantoms as opposed to solid phantoms. Investigations are performed to measure the penetration rates of water into radiochromic film and to assess the effects on optical density that this penetration causes. The effects of film orientation during irradiation in water are also tested. Results show that only a small penetration rate is seen from water into the film which only affects the outer areas of the film, with penetration being less than 0.5 mm per hour. The optical density measurements of the film at 660 nm remain unchanged in the unaffected regions of the radiochromic film. Minimal effects are seen due to beam orientation in a water phantom as opposed to solid water phantoms in which an overestimation in dose is normally seen for parallel irradiation. Radiochromic film seems to be an adequate detector for dosimetry in a water phantom where high spatial resolution is needed and angle of beam incidence at the point of interest is important.
[1]
J Cygler,et al.
GafChromic MD-55: investigated as a precision dosimeter.
,
1997,
Medical physics.
[2]
G S Ibbott,et al.
Dosimetric characteristics of an improved radiochromic film.
,
1996,
Medical physics.
[3]
J. Galvin,et al.
Radiochromic film dosimetry: recommendations of AAPM Radiation Therapy Committee Task Group 55. American Association of Physicists in Medicine.
,
1998,
Medical physics.
[4]
Optical density dependence on postirradiation temperature and time for MD-55-2 type radiochromic film
,
1999
.
[5]
N Suchowerska,et al.
Perturbation of radiotherapy beams by radiographic film: measurements and Monte Carlo simulations.
,
1999,
Physics in medicine and biology.
[6]
R. Nath,et al.
Photon energy dependence of the sensitivity of radiochromic film and comparison with silver halide film and LiF TLDs used for brachytherapy dosimetry.
,
1991,
Medical physics.