Impact of respiratory motion correction in F-18-FDG PET/CT on staging in lung cancer patients

Ziel/Aim Motion correction in PET has impact on quantitative PET parameters of structures affected by respiratory motion and increases subjective image quality. So far however, only few studies focused on the impact of motion correction on TNM staging in oncologic PET. The aim of this study was to evaluate the impact of motion correction on TNM staging of lung cancer patients.

Methodik/Methods 43 patients underwent initial F-18-FDG PET/CT for suspected lung cancer with respiratory motion assessment. Three different PET reconstructions were investigated: non-motion-corrected (“Static”), belt gating-based motion-corrected (“BG-MC”) and data-driven gating-based motion-corrected (“DDG-MC”). Datasets were independently reviewed by two nuclear medicine specialists blinded to the reconstruction method on a six point scale ranging from “certainly negative” (1) to “certainly positive” (6). Differences in between reconstruction methods, accounting for variation caused by readers, were assessed by non-parametric regression analysis of longitudinal data. A dichotomous (“negative”, “positive”) and a subjective certainty score were derived from . Additionally, SUV and metabolic tumor volumes (MTV) were compared between reconstruction methods.

Ergebnisse/Results Reading of BG-MC resulted in higher scores for N1 compared to Static images (p=0.001), whereas DDG-MC resulted in higher scores for N2 compared to Static (p=0.016). Motion correction resulted in the migration of N1 from tumor-free to metastatic on the dichotomized score, consensually for both readers, in 3/43 cases and in 2/43 for N2. SUV were significantly higher for motion-corrected PET, MTV significantly lower (all p<0.003). No differences in the certainty scores were noted.

Schlussfolgerungen/Conclusions PET motion correction influences decision making of human readers in some cases regarding N staging and has significant effects on quantitative PET parameters.