Page 118 - 18F-FDG PET as biomarker in aggressive lymphoma; technical and clinical validation

Chapter 5
comparability of ICCs within and between studies. Therefore, we also presented CoVs and Bland-Altman plots which are not dependent on the variability of MTV values among patients.
Finally, a preselection strategy as suggested in this study is not yet widely available in other commercially available (clinical) software tools but could be implemented relatively easily after validation in a larger patient cohort.
Future research should focus on the comparison of a preselection strategy in a larger patient cohort with different segmentation methods, their success rates, and the effect on the prognostic value of MTV and TLG measurements. A possible solution for the problem that none of the methods will be satisfactory in each patient and for each lesion could be the use of a MV approach, which should be investigated further. In addition, the effect of reconstruction settings, different uptake times, and effect of adding small lesions on the accuracy of MTV and TLG measurements should be addressed.
Conclusions
A semi-automated workflow based on individual lesion selection (Workflow A) is not recommended, because of the large differences observed in lesion selection. Using a fully automated preselection (SUV≥4.0 and volume≥3ml, Workflow B) of lesions improved interobserver reliability and ease of use of MTV and TLG assessment in DLBCL patients. Subsequent manual modification (Workflow C) is necessary for some patients, but this reduced interobserver reliability which may need to be balanced against any potential improvement of prognostic accuracy.
Acknowledgements
The authors thank all the patients who took part in the trials and the collaborating investigators that kindly supplied their trial data.
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