Image-based SPECT calibration based on the evaluation of the Fraction of Activity in the Field of View

• DOI: 10.1186/s40658-018-0209-8
• Publication Date: 2018-04-19T11:31:37Z
• Authors: Adrien Halty; Jean-Noël Badel; Olga Kochebina; David Sarrut
• Keywords: Collimator; Correction for attenuation; Spect imaging

SPECT quantification is important for dosimetry in targeted radionuclide therapy (TRT) and the calibration of images a crucial stage image quantification. The current standardized protocol (MIRD 23) uses phantom acquisitions to derive global factor specific conditions. It thus requires every clinical protocols. We proposed an alternative complementary image-based method that allows determine adapted each patient, radionuclide, acquisition may also be used as additional independent calibration. relies on SPECT/CT given region interest initial whole-body (WB) planar image. First, conjugate view WB computed after scatter attenuation correction. 3D are reconstructed with scatter, attenuation, collimator-detector response (CDR) corrections corrected from apparent dead-time. field (FOV) then projected fraction activity located area corresponding FOV calculated based counts Fraction Activity Field Of View (FAF) compute total number divided by this activity. Quantification accuracy was compared standard both experiments patient data. Both calibrations give good large (less than 7% relative difference ground truth). Apparent dead-time correction reduce uncertainty associated 2.5 1%. differences found between methods were lower range (<3%). In data, although no truth available, similar (average 3.64%). A directly acquired providing available if performed before biological elimination. This does not require perform different conditions serve double check factor.