18F-FDG PET/CT in lung cancer. The added value of quantification.

OBJECTIVE: To test a software application for the quantification of metabolic heterogeneity and to evaluate its superiority in relation to visual interpretation. To investigate if a quantitative analysis adds information to the interpretation of 18F-FDG-PET/CT. MATERIAL AND METHODS: The study analyzed 215 patients with a 18F-FDG-PET/CT done for the initial staging of lung cancer between March 2011 and December 2015. The study included 57 (26.5%) women and 158 (73.5%) men, with ages ranging from 34 to 88 years (mean±SD: 67.23±10.04). There were 82 surgical stages (I, II, IIIA), and 133 non-surgical stages (IIIB, IV). The primary tumour was analyzed quantitatively by obtaining the following parameters: SUVmax, metabolic active tumour volume (MATV), total lesion glycolysis (TLG), and the entropy heterogeneity index (ET). Heterogeneity was assessed visually. Death dates and/or the follow-up time were registered, ranging from 0.70 to 67.60 months (mean±SD: 23.20±17.68). RESULTS: In multivariate analysis, ET emerged as a better predictor of survival than visual analysis of heterogeneity that was not statistically significant. The C-index determination demonstrated that all quantitative parameters were statistically-significant predictors of survival. Cut-offs were obtained in order to compare survival times. A multivariate analysis was performed. In the total population, the best predictor was the TNM stage, but MATV, ET, and male gender were statistically significant and independent predictors of survival. In stages without surgical indication, the best predictor was the TNM stage, but the MATV and male gender were statistically significant and independent predictors of survival. In the surgical stages, ET was the only statistically significant and independent predictor of survival. CONCLUSIONS: Quantification adds prognostic information to the visual analysis of 18F-FDG-PET/CT.

Articular lymphoscintigraphy in human knees using radiolabeled dextran.

Whereas joint lymphatics are inaccessible to conventional (oil-contrast) lymphography, articular lymphatic dysfunction can be assessed by lymphoscintigraphy (isotope lymphography). Using 99mTc-labeled dextran (molecular weight-70,000 daltons), we performed dynamic lymphoscintigraphy in 38 patients with degenerative osteoarthropathy of the knee. Comparison with the normal (contralateral knee) in 25 patients demonstrated that tracer disappeared at 24 hours more slowly from the abnormal side (86.5 +/- 3.3% retention in the abnormal joint compared with 77.1 +/- 4.6%; p less than 0.01), but accumulated more intensely in regional lymph nodes on the pathologic side (3.8 +/- 2.4% vs 1.9 +/- 0.3%; p less than 0.01). The findings suggest deranged macromolecular transport and lymphatic dysfunction in degenerative knee joint disease.