Quality control performance evaluation of uMI550 digital PET-CT by utilising LYSO crystal natural radioactivity of 176Lu

Abstract

Purpose

Quality Control (QC) of the Positron Emission Tomography-Computed Tomography (PET-CT) system must be performed prior to the PET-CT acquisition to ensure the reproducibility as per the manufacturer recommendation. In this study we have evaluated the performance of daily PET QC test by utilising lutetium yttrium oxyorthosilicate (LYSO) scintillation crystal natural radioactivity of ¹⁷⁶Lu as a source of radiation to perform the PET uCare.iQC with uMI550 digital PET-CT system. This was also compared with existing radioactive external source-based QC test with other manufacturer PET-CT systems.

Method

This radioactive source free daily QC study was performed on uMI550 digital PET-CT system. The daily QC data report was captured and interpreted. This PET-CT system has unique feature that utilises the inherent property of LYSO crystal that is ¹⁷⁶Lu with natural radioactivity abundance of 2.6%. The Lutetium-176 (¹⁷⁶Lu) radioactivity is used to perform the daily QC in PET in place of external radioactive source of Germanium-68 (⁶⁸Ge). This feature work automatically in preschedule manner to complete the daily QC at preset time in the morning and system get ready after the QC test.

Results

Over 120 automatic PET daily uCare.iQC test were performed. The daily PET QC test was prescheduling setup for 6:00 am in every morning. No failure on daily QC test were observed. The QC parameters and system parameters consistency was observed.

Conclusion

It was concluded that the daily PET QC can be performed by utilising LYSO crystal inherent natural radioactivity of ¹⁷⁶Lu as a source of radiation to perform the test as replacement of external ⁶⁸Ge radioactive source.

Implication for practice

PET-CT daily QC by utilizing the ¹⁷⁶Lu radioactivity of LYSO crystal results in reducing the radiation exposure to operation staff and reducing operational cost by elimination 68Ge shield source Phantom.