Room: Exhibit Hall | Forum 8
Purpose: To evaluate the performance of Celesteion large bore PET/CT used as a CT simulator, based on the AAPM Task Group 66 (TG-66) report and ACR CT Accreditation Program.
Methods: CT Dose Index (CTDI) was measured using the 16 cm and 32 cm CTDI phantoms and a pencil ion chamber as described in TG-66 report. A TG-66 laser QA phantom was used to evaluate the performance of the electromechanical components. Image quality was evaluated using the Gammex 464 phantom following the instructions in the ACR CT Accreditation Program. We also evaluated mA linearity and mA reproducibility using a pencil ion chamber.
Results: The CTDI measurements were within 20% of the values reported by the scanner as specified in TG-66. The alignment and orientation for both gantry laser and tabletop, as well as the table movement and indexing and scanogram location accuracy were within 2mm as specified in TG-66. The spatial resolution, low contrast resolution, field uniformity and CT number accuracy were all within ACR's recommended limits. The mA linearity and reproducibility were both below the TG-66 threshold.
Conclusion: Canonâ€™s Celesteion large bore PET/CT is designed with a true scan field of view (FOV) of 70 cm and 90cm CT bore size, which makes it preferable for CT simulation in radiation therapy. The results demonstrated that this simulator complies with the requirements set in both AAPM TG-66 report and ACR CT Accreditation Program including CT dosimetry, electromechanical components performance and image quality. Celesteion large bore PET/CT meets the requirements for CT simulation in radiation therapy.