AIM: To evaluate the value of an integrated approach in the management of Gastric Cancer (GC) patients by means of quantitative biomarkers from multimodal 18F-FDG PET and Diffusion Weighted MR (MR-DWI) studies. MATERIALS AND METHODS: 17 patients affected by GC (3 in oesophageous, 3 in gastroesophageous- junction and 11 in gastric cancer) were enrolled and studied by a multimodal PET-MR quantitative approach. Patients performed: 18F-FDG PET/CT basal study (PET-I) (1mCi/10kg, 45 min from radiotracer injection), MR -DWI basal study (DWI-I) (1.5-T MR system, SSEPI sequence, b=600s/mm2), neo-adjuvant chemotherapy (NC), 18F-FDG PET/CT follow up study (PET-II), MR DWI follow up study (DWI-II), radical surgery with histopathological analysis. For each detected GC lesion, Partial Volume Corrected Body-Weight Standardized Uptake Value (PVC-SUVBW) was estimated from both PET-I and PET-II and Apparent Diffusion Coefficient (ADC) from both DWI-I and DWI-II. pT classification (infiltrating, non infiltrating), histological type (signet ring cell carcinoma, adenocarcinoma subtype and squamous cell carcinoma), and Tumor Regression Grade (TRG) were determined from histopathological analysis. By using statistical tests (Mann Whitney and Kruskal Wallis tests), PVC-SUVBW and ADC were correlated with histopathological findings, ?PVC-SUVBW and ?ADC with TRG. RESULTS: PVC-SUVBW was found significantly different in infiltrating vs non infiltrating pathologies (8.1±6.2 g/cc vs 3.1±1.0g/cc; p<0.05), and in signet ring cell, adenocarcinoma and squamous cell histological types (5.57±3.22 g/cc vs 9.32 ± 4.26g/cc vs 9.90 ± 1.91g/cc; p=0.05). No significant correlations were found between ?PVC-SUVBW and TRG. ADC changes was found significantly different in responder patients (TRG = 1-3) vs non responder patients (TRG = 4-5) (106±79% vs -8±22%; p<0.01). No significant correlations were found with different infiltration characteristics and with different histological types. CONCLUSIONS: PVC-SUVBW can be considered a diagnostic biomarker in GC, allowing to define in vivo and non-invasively the infiltration level. ADC can be considered a biomarker predictive of therapeutic response to NC in GC, allowing to stratify responder and non responder patients. Our preliminary results suggest the combination of multi-modal PET and MR-DWI studies as a powerful approach for the diagnostic and therapeutic management of GC patients, opening the use of hybrid PET/MR systems to these pathologies.
Integration of quantitative biomarkers from in vivo multi-modal PET and MR studies for the diagnostic and therapeutic management of Gastric Cancer patients
Francesca Gallivanone;Maria Carla Gilardi;Isabella Castiglioni;
2012
Abstract
AIM: To evaluate the value of an integrated approach in the management of Gastric Cancer (GC) patients by means of quantitative biomarkers from multimodal 18F-FDG PET and Diffusion Weighted MR (MR-DWI) studies. MATERIALS AND METHODS: 17 patients affected by GC (3 in oesophageous, 3 in gastroesophageous- junction and 11 in gastric cancer) were enrolled and studied by a multimodal PET-MR quantitative approach. Patients performed: 18F-FDG PET/CT basal study (PET-I) (1mCi/10kg, 45 min from radiotracer injection), MR -DWI basal study (DWI-I) (1.5-T MR system, SSEPI sequence, b=600s/mm2), neo-adjuvant chemotherapy (NC), 18F-FDG PET/CT follow up study (PET-II), MR DWI follow up study (DWI-II), radical surgery with histopathological analysis. For each detected GC lesion, Partial Volume Corrected Body-Weight Standardized Uptake Value (PVC-SUVBW) was estimated from both PET-I and PET-II and Apparent Diffusion Coefficient (ADC) from both DWI-I and DWI-II. pT classification (infiltrating, non infiltrating), histological type (signet ring cell carcinoma, adenocarcinoma subtype and squamous cell carcinoma), and Tumor Regression Grade (TRG) were determined from histopathological analysis. By using statistical tests (Mann Whitney and Kruskal Wallis tests), PVC-SUVBW and ADC were correlated with histopathological findings, ?PVC-SUVBW and ?ADC with TRG. RESULTS: PVC-SUVBW was found significantly different in infiltrating vs non infiltrating pathologies (8.1±6.2 g/cc vs 3.1±1.0g/cc; p<0.05), and in signet ring cell, adenocarcinoma and squamous cell histological types (5.57±3.22 g/cc vs 9.32 ± 4.26g/cc vs 9.90 ± 1.91g/cc; p=0.05). No significant correlations were found between ?PVC-SUVBW and TRG. ADC changes was found significantly different in responder patients (TRG = 1-3) vs non responder patients (TRG = 4-5) (106±79% vs -8±22%; p<0.01). No significant correlations were found with different infiltration characteristics and with different histological types. CONCLUSIONS: PVC-SUVBW can be considered a diagnostic biomarker in GC, allowing to define in vivo and non-invasively the infiltration level. ADC can be considered a biomarker predictive of therapeutic response to NC in GC, allowing to stratify responder and non responder patients. Our preliminary results suggest the combination of multi-modal PET and MR-DWI studies as a powerful approach for the diagnostic and therapeutic management of GC patients, opening the use of hybrid PET/MR systems to these pathologies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
