BackgroundThe aim of the present study was to evaluate the predictive value of a novel quantitative measure for the spatial heterogeneity of FDG uptake, the asphericity (ASP) in patients with non-small cell lung cancer (NSCLC).MethodsFDG-PET/CT had been performed in 60 patients (15 women, 45 men; median age, 65.5 years) with newly diagnosed NSCLC prior to therapy. The FDG-PET image of the primary tumor was segmented using the ROVER 3D segmentation tool based on thresholding at the volume-reproducing intensity threshold after subtraction of local background. ASP was defined as the relative deviation of the tumor’s shape from a sphere. Univariate and multivariate Cox regression as well as Kaplan-Meier (KM) analysis and log-rank test with respect to overall (OAS) and progression-free survival (PFS) were performed for clinical variables, SUVmax/mean, metabolically active tumor volume (MTV), total lesion glycolysis (TLG), ASP and “solidity”, another measure of shape irregularity.ResultsASP, solidity and “primary surgical treatment” were significant independent predictors of PFS in multivariate Cox regression with binarized parameters (HR, 3.66; p < 0.001, HR, 2.11; p = 0.05 and HR, 2.09; p = 0.05), ASP and “primary surgical treatment” of OAS (HR, 3.19; p = 0.02 and HR, 3.78; p = 0.01, respectively). None of the other semi-quantitative PET parameters showed significant predictive value with respect to OAS or PFS. Kaplan-Meier analysis revealed a probability of 2-year PFS of 52% in patients with low ASP compared to 12% in patients with high ASP (p < 0.001). Furthermore, it showed a higher OAS rate in the case of low versus high ASP (1-year-OAS, 91% vs. 67%: p = 0.02).ConclusionsThe novel parameter asphericity of pretherapeutic FDG uptake seems to provide better prognostic value for PFS and OAS in NCSLC compared to SUV, metabolic tumor volume, total lesion glycolysis and solidity.

and N.T. are salaried employees of F. Hoffmann-La Roche. F.F. is a salaried employee of Roche Molecular Systems. S.Y. is an employee of Roche Sequencing Solutions. L.T.F. is a salaried employee of Roche Sequencing Solutions and owns stock in F. Hoffmann-La Roche. S.F. is a salaried employee of and owns stock in F. Hoffmann-La Roche. H.J.A. reports personal fees from AstraZeneca, Bristol-Myers Squibb, Boehringer Ingelheim, Novartis, Insmed, Grifols, and Roche outside the submitted work. R.K. reports personal fees from Bristol-Myers Squibb, Boehringer Ingelheim, Novartis, Merck Sharp & Dohme, Mediolanum, and Roche. Support for thirdparty writing assistance for this manuscript was provided by CodonMedical, an Ashfield Company, part of UDG Healthcare plc, and was funded by F. Hoffmann-La Roche.

The ASP of primary NSCLCs on FDG PET images is associated with tumour dimensions and molecular markers of proliferation and angiogenesis.

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• DTPI did not improve accuracy of PET-based LN staging in NSCLC. • Analyzed SUV ratios were not superior to LN SUVmax or SUVmean. • A four-step visual score may allow highly accurate, standardized LN assessment.