GafChromic RTQA Film을 이용한 광역학적 치료용 레이저의 선질 측정

Abstract

Abstract: Purpose: The purposes of this study were to measure the dose distribution of Photodynamic ther-apy(PDT) laser with 635 nm wavelength using GafChromic film. Method & Result: We made each output 300 J bychanging mW and sec using the laser beam radiation mode such as C.W(Continuous Wave) mode, Pulse mode andBurst Pulse mode and measured the does at 0 mm and 5 mm of distance from optic fiber catheter end to the film,and at 5 mm distance by changing the angle of the end of the optic fiber catheter as 0 o and 0.5 o . The radiated filmwas scanned and OD(Optical Density) was compared. And two-dimensional isodose curves were obtained and theconsistency of shapes was compared. It was confirmed that there was consistency between optic density and thedose radiated on the film when we radiated GafChromic film by changing distance and angle of 300 J output in eachradiation mode coordinating mW and sec. Conclusion: In this study, we could identify the stability according tochanges in laser beam modes, changes in output according to distance, changes in uniformity according to angle, andbeam profiles using GafChromic film, and we could also get two-dimensional isodose curve. It was found that smallchange in the distance and angle that is made when optic fiber catheter was contacted on the treatment area did notmake big effects on the output of beam and the uniformity of dose, and it was also found that GafChromic film couldbe utilized for the purpose of QA of PDT laser beam.Key words: GafChromic film, change in radiation mode, beam profile, two-dimensional isodose curve