CT texture analysis compared to Positron Emission Tomography (PET) and mutational status in resected melanoma metastases.

Olthof, Susann-Cathrin; Krumm, Patrick; Weichold, Oliver; Eigentler, Thomas; Bösmüller, Hans; la Fougère, Christian; Pfannenberg, Christina; Martus, Peter; Klumpp, Bernhard

PURPOSE To evaluate the potential of CT texture analysis parameters and metabolic characteristics of melanoma metastases in 18F- FDG PET/CT to predict relevant mutations of tumour cells for targeted therapy in metastatic melanoma patients in correlation with histopathologic specimen. MATERIAL AND METHODS 66 melanoma patients, examined with contrast-enhanced 18F-FDG PET/CT before scheduled metastasectomy without any prior systemic therapy, were included in this single-centre retrospective analysis under IRB waiver. The largest, resected metastasis in each patient was assessed with CT texture analysis and semiquantitative 18F-FDG PET parameters. Correlation between imaging parameters and histopathological mutations (BRAF- and NRAS- genes) were calculated. RESULTS Attenuation standard deviation (SD) within target lesion indicated a weak correlation with its SUVpeak (rho -0.292, p 0.017). However, no correlation between CT texture analysis, metabolic 18F-FDG PET parameters and tumour cell mutation could be established. CONCLUSION CT texture parameters cannot replace the diagnostic value of 18F- FDG PET/CT for metabolic information in melanoma patients. Discrimination between BRAF- and NRAS mutation status was not feasible with CT texture analysis in this exploratory study.