Fractal Dimension Characteristic Analysis for Dose Verification in Intensity Modulation Radiation Therapy

This study described how to identify the coincidence of desired planning isodose curves with film experimental results by using a mathematical fractal dimension characteristic method to avoid the errors caused by visual inspection. These film's isodose curves were acquired to Osiris (Geneva University Hospital) software to aim directly on single interested dose curve for fractal characteristic analysis and the results were compared with the corresponding planning desired isodose curves for fractal dimension analysis so as to broach a criterion to determine the coincidence in between planning and measurement. the film measured isodose curves and computer planning curves are deemed identical in dose distribution if their fractal dimensions are within some criterion which implicate that fractal dimension is a unique fingerprint of a curve in checking planning and film measurement results. Dose measured result of film is presumed to be the same if their fractal dimension are within 1%. the comparison of treatment planning isodose distributions and film dosimetry measurement can be more accurately done by fractal dimension numerical analysis, and furthermore mathematic way to do comparison reduce visual inspection discrepancy. This quantitative rather than qualitative comparison procedure will help decrease errors in dosimetry verification.