39 - Freie Mitteilung
Clinical works I
16. Mai 2019, 08:30 - 10:00, Bellavista 2, 6. OG
Implementing CT tumor volume and CT pleural thickness into future staging systems for malignant pleural mesothelioma
O. Lauk, M. Patella, M. Friess, T. Frauenfelder, D. L. Nguyen-Kim, S. Hillinger, I. Inci, W. Weder, I. Opitz, Presenter: M. Patella (Zurich)
Tumor thickness and tumor volume measured by computed tomography (CT) were suggested as valuable prognosticator for malignant pleural mesothelioma (MPM) patients’ survival. The purpose was to assess the accuracy of CT scan based preoperatively measured tumor volume and thickness. Therefore, we correlated the resected tumor weight and pathologically assessed tumor thickness to the CT derived data. Additionally, we calculated their impact on overall survival (OS) of patients resected after induction chemotherapy.
From 09/2013 – 08/2018, 73 patients were treated with induction chemotherapy followed by (extended) pleurectomy/decortication ((e)P/D). In 62 patients correlations were made between CT-volume and -tumor thickness and tumor weight. Further tumor volume and maximum tumor thickness of pathological specimen, as well as pT/IMIG stage were correlated using Pearson correlation. For correlation with OS Kaplan-Meier curves were made and log rank test was performed for all measurements dichotomized at the median. Overall survival was calculated with Kaplan-Meier analysis and tested with long rank test.
The analysis revealed a strong correlation between CT tumor volume (median 76ml (1.5-787ml) and actual tumor weight (median 464.5g (95-982g)) (correlation coefficient r2=0.677, p<0.001) and actual tumor volume at surgery (530ml (130-1000ml)) (r2=0.654, p<0.001). There was a moderate correlation between maximal CT thickness (median 8.9mm (3.1-39.8mm)) and pT stage and IMIG stage (both: r2=0.430, p=0.001,). OS was significantly influenced by CT tumor volume (p=0.04), CT thickness (maximum thickness, p=0.001) and the most, by the combination of both measurements (p=0.006) with a cut off at 76ml and 8.9mm, respectively (Figure).
The correlation between preoperatively assessed CT tumor volume and actual tumor volume as well as tumor weight showed a moderate to strong correlation and furthermore significantly influenced OS. However, even though CT thickness does not correlate to pathologically assessed tumor thickness, the impact on OS is at least equivalent and therefore supporting integration of CT tumor volume and tumor thickness into future staging systems.