Application of OSL strips in CT dosimetry according to the AAPM methodology

Computed tomography (CT) images contribute to high-quality medical diagnosis, but radiation dose can be quite high, requiring accurate assessment. CT index (CTDI) was developed for dosimetric purposes, scanners operated exclusively in axial mode. Nowadays, CTDI underestimate patient helical exams. AAPM report TG111 (2010) suggested a new metric which the patient's is obtained from profiles constructed several measurements made with small ionization chamber. It also possible obtain using properly calibrated OSL (optically stimulated luminescence) strips. The main objective of present work optimizing dosimetry, comparing strips by other authors. In this work, “pencil” chamber and 20 cm x 0.3 were X-ray-irradiated, air holes two cylindrical phantoms, 100, 120, 140 kV peak voltages, both lab clinical scanner. Irradiated read an reader built GDRFM. against From them, CTDIw CTDIvol values determined, differing approximately 3.9% those profiles, planar equilibrium Deq,p (TG111) evaluated some protocols; exceeded scanner every case. E.g.: percentage difference between head phantom ranged 33-25%. Thus, cases, it could advantageous use dosimeters instead chambers saving time, because five single irradiation.