Generating harmonized SUV within the EANM EARL accreditation program: software approach versus EARL-compliant reconstruction.
BACKGROUND
Evolutions in hardware and software PET technology, such as point spread function (PSF) reconstruction, have been shown to improve diagnostic performance, but can also lead to important device-dependent and reconstruction-dependent variations in standardized uptake values (SUVs). This may preclude the multicentre use of SUVs as a prognostic or diagnostic tool or as a biomarker of the early response to antineoplastic treatments. This study compared two SUV harmonization strategies using a newer reconstruction algorithm that improves lesion detection while maintaining comparability with older systems: (1) the use of a second reconstruction compliant with harmonization standards and (2) the use of a proprietary software tool (EQ.PET).


METHODS
PET data from 50 consecutive non-small cell lung cancer patients were reconstructed with PSF reconstruction for optimal tumor detection and an ordered subset expectation maximization (OSEM3D) reconstruction to mimic a former generation PET. An additional PSF reconstruction was performed with a 7 mm Gaussian filter (PSF7, first method), and, post-reconstruction, the EQ filter (same Gaussian filter) was applied to the PSF data (PSFEQ, second method) for harmonization purposes. The 7 mm kernel filter was chosen to comply with the European Association of Nuclear Medicine (EANM) standards. SUVs for all reconstructions were compared with regression analyses and/or Bland-Altman plots.


RESULTS
Overall, 171 lesions were analyzed: 55 lung lesions (32.2%), 87 lymph nodes (50.9%), and 29 metastases (16.9%). In these lesions, the mean PSF7/OSEM3D ratios for SUVmaxand SUVpeakwere 1.02 (95% CI: 0.93-1.11) and 1.04 (95% CI: 0.95-1.14), respectively. The mean PSFEQ/OSEM3D ratios for SUVmaxand SUVpeakwere 1.01 (95% CI: 0.91-1.11) and 1.04 (95% CI: 0.94-1.14), respectively. When comparing PSF7and PSFEQ, Bland-Altman analysis showed that the mean PSF7/PSFEQratios for SUVmaxand SUVpeakwere 1.01 (95% CI: 0.96-1.06) and 1.01 (95% CI: 0.97-1.04), respectively.


CONCLUSIONS
The issue of reconstruction dependency in SUV values that hampers the comparison of data between different PET systems can be overcome using two reconstructions for harmonized quantification and optimal diagnosis or using the EQ.PET technology. Both technologies produce similar results, EQ.PET sparing reconstruction and interpretation time. Other manufacturers are encouraged to either emulate this solution or to produce a vendor-neutral approach.
Nuclear Medicine Department, Caen University Hospital, Avenue Côte de Nacre, 14000, Caen, France.|INSERM 1199, François Baclesse Cancer Centre, Caen, France.|Normandie University, Caen, France.
Charline
C
Lasnon
Nuclear Medicine Department, Caen University Hospital, Avenue Côte de Nacre, 14000, Caen, France.
Thibault
T
Salomon
Nuclear Medicine Department, Caen University Hospital, Avenue Côte de Nacre, 14000, Caen, France.
Cédric
C
Desmonts
Thoracic Oncology, François Baclesse Cancer Centre, Caen, France.
Pascal
P
Dô
Pulmonology Department, Caen University Hospital, Caen, France.
Youssef
Y
Oulkhouir
Pulmonology Department, Caen University Hospital, Caen, France.
Jeannick
J
Madelaine
Nuclear Medicine Department, Caen University Hospital, Avenue Côte de Nacre, 14000, Caen, France. aide-n@chu-caen.fr.|INSERM 1199, François Baclesse Cancer Centre, Caen, France. aide-n@chu-caen.fr.|Normandie University, Caen, France. aide-n@chu-caen.fr.
Nicolas
N
Aide
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015992:Body Mass Index; D002138:Calibration; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012984:Software
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
18F-Fluorodeoxyglucose; Harmonization; Positron emission tomography; Quantitation; Standardized uptake value