Abstract
PurposePoint-spread function (PSF) or PSF + time-of-flight (TOF) reconstruction may improve lesion detection in oncologic PET, but can alter quantitation resulting in variable standardized uptake values (SUVs) between different PET systems. This study aims to validate a proprietary software tool (EQ.PET) to harmonize SUVs across different PET systems independent of the reconstruction algorithm used.MethodsNEMA NU2 phantom data were used to calculate the appropriate filter for each PSF or PSF+TOF reconstruction from three different PET systems, in order to obtain EANM compliant recovery coefficients. PET data from 517 oncology patients were reconstructed with a PSF or PSF+TOF reconstruction for optimal tumour detection and an ordered subset expectation maximization (OSEM3D) reconstruction known to fulfil EANM guidelines. Post-reconstruction, the proprietary filter was applied to the PSF or PSF+TOF data (PSFEQ or PSF+TOFEQ). SUVs for PSF or PSF+TOF and PSFEQ or PSF+TOFEQ were compared to SUVs for the OSEM3D reconstruction. The impact of potential confounders on the EQ.PET methodology including lesion and patient characteristics was studied, as was the adherence to imaging guidelines.ResultsFor the 1380 tumour lesions studied, Bland-Altman analysis showed a mean ratio between PSF or PSF+TOF and OSEM3D of 1.46 (95 %CI: 0.86–2.06) and 1.23 (95 %CI: 0.95–1.51) for SUVmax and SUVpeak, respectively. Application of the proprietary filter improved these ratios to 1.02 (95 %CI: 0.88–1.16) and 1.04 (95 %CI: 0.92–1.17) for SUVmax and SUVpeak, respectively. The influence of the different confounding factors studied (lesion size, location, radial offset and patient’s BMI) was less than 5 %. Adherence to the European Association of Nuclear Medicine (EANM) guidelines for tumour imaging was good.ConclusionThese data indicate that it is not necessary to sacrifice the superior lesion detection and image quality achieved by newer reconstruction techniques in the quest for harmonizing quantitative comparability between PET systems.Electronic supplementary materialThe online version of this article (doi:10.1007/s00259-015-3128-0) contains supplementary material, which is available to authorized users.
Highlights
Standardized uptake values (SUVs) extracted from FDG-PET/ CT are being increasingly used as non-invasive quantitative imaging biomarkers in oncology
This issue was exemplified by the RATHL Lymphoma trial ([5]), which mandated that centres with point spread function (PSF) reconstruction or time of flight (TOF) disable these features when participating in the study
The PET exams of 517 consecutive patients from three centres referred for staging or restaging of non-small cell lung cancer (NSCLC), melanoma, non-Hodgkin lymphoma (NHL) or liver metastases from colorectal cancer were included over a 9-month period
Summary
Standardized uptake values (SUVs) extracted from FDG-PET/ CT are being increasingly used as non-invasive quantitative imaging biomarkers in oncology. Eur J Nucl Med Mol Imaging (2015) 42:2072–2082 comparable regardless of the imaging site or PET system used By harmonizing both patient preparation as well as acquisition and reconstruction parameters, various groups, including the European Association Research Ltd (EARL) accreditation program [1], the North American Quantitative Imaging Biomarker Alliance (QIBA) [2] and Uniform Protocols in Clinical Trials (UPICT) [3, 4], aim to harmonize standardized uptake values (SUV) in the multicentre trial setting. Centres running PET systems with advanced reconstruction algorithms are requested in some clinical trials to revert to older reconstruction so that their data is comparable to other centres with older systems This issue was exemplified by the RATHL Lymphoma trial ([5]), which mandated that centres with point spread function (PSF) reconstruction or time of flight (TOF) disable these features when participating in the study. It is important to develop strategies that enable use of newer reconstruction algorithms that improve lesion detection, whilst maintaining the compatibility of SUV with older systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
