Comparison of a 3D CZT and conventional SPECT/CT system for quantitative Lu-177 SPECT imaging

• DOI: 10.1186/s40658-024-00627-1
• Publication Date: 2024-03-19T03:02:44Z
• Authors: Victor Nuttens; Georg Schramm; Yves D’Asseler; Michel Koole
• Keywords: Gaussian filter

Abstract Purpose Next-generation SPECT/CT systems with CdZnTe (CZT) digital detectors in a ring-like setup are emerging to perform quantitative Lu-177 SPECT imaging clinical routine. It is essential assess how the shorter acquisition time might affect image quality and uncertainty on mean absorbed dose of tumors organs at risk compared conventional system. Methods A NEMA Image Quality phantom was scanned 3D CZT system (Veriton, by Spectrum Dynamics) using 6 min per bed position (Symbia T16, Siemens) 16 position. The sphere-to-background ratio 12:1 background activity concentration ranged from 0.52 0.06 MBq/mL. reconstruction protocol for dosimetry purposes determined both maximizing while keeping coefficient variation as low possible. corresponding resolution matching filter method used assessment following an established model.. Results optimized iterative included scatter attenuation correction detector response modeling Siemens For system, iterations 8 subsets were combined Gaussian post-filter 3 mm Full Width Half Maximum (FWHM) post-smoothing. applied post-smoothing 1 FWHM. these protocols, 18.5% closer true when considering four largest spheres. Meanwhile, very similar systems. These protocols resulted 14.8 13.6 respectively. Based estimates, 50% corresponded lesion volume 28 mL 33 Conclusions An Veriton slightly higher uncertainties than Symbia Therefore, allows significantly reduce times only limited impact such that becomes much more accessible treatment concurrent dosimetry. Nevertheless, SPECT-based estimates remains high.