Iron-based radiochromic systems for UV dosimetry applications

Abstract

Phototherapy treatment using ultraviolet (UV) A and B light sources has long existed as a treatment option for various skin conditions. Quality control for phototherapy treatment recommended by the British Association of Dermatologists and British Photodermatology Group generally focused on instrumentation-based dosimetry measurements. The purpose of this study was to present an alternative, easily prepared dosimeter system for the measurement of UV dose and as a simple quality assurance technique for phototherapy treatments. Five different UVA-sensitive radiochromic dosimeter formulations were investigated and responded with a measurable and visible optical change both in solution and in gel form. Iron(III) reduction reaction formulations were found to be more sensitive to UVA compared to iron(II) oxidation formulations. One iron(III) reduction formulation was found to be especially promising due to its sensitivity to UVA dose, ease of production, and linear response up to a saturation point.

3D dosimetry of proton beams and influences on response

“…The ferrous sulfate is mixed with gelatin or another stabilizing agent, although some migration of the ferrous and ferric ions has been observed. The ferric ion concentration can be determined by optical methods, especially if a coloring agent such as xylenol orange is used, although MRI is often used [9]. A novel demonstration of the use of Fricke gels was shown by Lee et al, who used an MR-linac to image a gel as it was being irradiated, measuring the dose as it was being deposited [10].…”