Characterization of noise and digitizer response variability in radiochromic film dosimetry. Impact on treatment verification.
OBJECTIVE
To study how noise and scanner response variability affect radiochromic film dosimetry.


METHODS
Five treatment plans were analyzed in this work with two different multichannel protocols: the multichannel algorithm of Mayer et al. and the efficient protocol of Lewis et al.


CONCLUSIONS
The multichannel protocol of Mayer et al. is not able to compensate variability in scanner response, which is an important issue for radiochromic film dosimetry. The efficient protocol compensates variations of scanner response, so dose values and gamma scores become more accurate and reproducible. The compensation of digitizer scan variability of the efficient protocol, together with time averaging improve radiochromic film dosimetry. Noise is related to selected resolution in the scanner, our results show that if high resolution measurements are required, de-noising should be considered.
Hospital Universitari Sant Joan de Reus, Servicio de Física Médica, Reus (Tarragona), Spain. Electronic address: javsphys@gmail.com.
Juan Antonio
JA
Vera Sánchez
Hospital IMED, Servicio de Oncología Radioterápica, Elche (Alicante), Spain.
Carmen
C
Ruiz Morales
Hospital Universitario Virgen de la Arrixaca, El Palmar (Murcia), Spain.
Antonio
A
González López
D000465:Algorithms; D016477:Artifacts; D001932:Brain Neoplasms / Q000532:radiotherapy; D002138:Calibration; D004867:Equipment Design; D005373:Film Dosimetry / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011829:Radiation Dosage; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software; D058067:Wavelet Analysis
Film dosimetry; Noise; Radiochromic; Scanner response