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This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Tylski, P. Articles by Buvat, I. PubMed Articles by Tylski, P. Articles by Buvat, I.

Which parameter should be considered to characterize tumor changes in patient monitoring using FDG-PET?

¹ UMR 8165 CNRS, Orsay, France; ² Institut Jules Bordet, Bruxelles, Belgium

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Objectives: In patient monitoring based on FDG PET, the best way to characterize changes in tumor uptake remains to be found. We compared the evolution of various parameters potentially relevant for patient monitoring.

Methods: Seventeen pairs of PET/CT tumor images (GE Discovery LS system) acquired 10 to 12 weeks apart over the course of chemotherapy in lung cancer patients were considered. Four delineation methods (expert delineation, 40% of maximum intensity threshold, a contrast-dependent threshold and a fitting method) gave 4 independent volume (V) and total lesion glycolysis (TLG) estimates. 6 independent SUV estimates were obtained using the maximum SUV, and the mean SUV in the 4 delineated regions and in a fixed-size region. Percent changes in tumor features (V, SUV and TLG) were compared to the clinician’s interpretation based on visual assessment and maximum SUV.

Results: Percent changes in tumor features highly varied depending on the estimation method. Considering the 17 image pairs, the average coefficients of variation due to different estimation methods were 35% for SUV, 80% for TLG and 138% for V. The clinician found 9 responding (RT), 2 stable (ST) and 6 progressive tumors (PT). SUV averaged over the 6 SUV estimation methods was always < 0 for RT and > 0 for ST and PT, except in one case. Averaged V was > 0 for PT and < 0 for ST. TLG alone could not differentiate between RT, PT and ST, suggesting that joint analysis of V and SUV gave more information than TLG analysis.

Conclusions: When characterizing tumor changes, SUV was the most reproducible parameter as a function of the estimation method. Unlike the analysis of TLG alone, the combined analysis of V and SUV led to a tumor classification similar to that obtained from the clinician interpretation.

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Tylski, P. Articles by Buvat, I. PubMed Articles by Tylski, P. Articles by Buvat, I.