Prognostic Value of Metabolic Information in Advanced Gastric Cancer Using Preoperative ¹⁸F-FDG PET/CT / 대한핵의학회잡지

PURPOSE: This study evaluated the usefulness of semiquantitative and volumetric PET parameters for predicting prognosis in patients with advanced gastric cancer (AGC).METHODS: We enrolled 213 patients who underwent ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) prior to curative surgery for AGC. Maximum standardized uptake value (SUVmax) and tumor-to-liver uptake ratio (TLR) were measured in all patients. Metabolic tumor volume (MTV) and total lesion glycolysis were measured in volume-measurable patients. For further quantification of FDG uptake, we developed PET prognostic scores by combining SUVmax and MTV (1: low SUVmax/low MTV; 2: high SUVmax/low MTV; 3: high SUVmax/high MTV). Comparison of PET parameters between recurrence and non-recurrence groups was performed. Univariate and multivariate analyses for recurrence-free survival (RFS) and overall survival (OS) were subsequently performed.RESULTS: The recurrence rate was 32.4% (69/213 patients). Mean SUVmax and mean MTV of the recurrence group were significantly higher than those of the non-recurrence group (p = 0.026 and p = 0.025). TLR showed marginal significance (p = 0.051). In multivariate analysis for RFS including all patients, SUVmax (p = 0.022), TLR (p = 0.010), and PET score (p = 0.003) were independent prognostic factors. In post hoc analysis of PET score, significant differences in RFS were observed between PET scores 2 and 3 as well as scores 1 and 3. No significant difference in RFS was observed between scores 1 and 2. Only PET score was statistically significant for OS in univariate analysis. None of the PET parameters were statistically significant for OS in multivariate analysis.CONCLUSION: High SUVmax and high MTV of the primary tumor suggest a high risk of recurrence for AGC patients. Even if SUVmax is similar, the prognosis may vary depending on MTV. Combining PET parameters results in a better prediction for prognosis.

Prognostic Value of Metabolic Information in Advanced Gastric Cancer Using Preoperative ¹⁸F-FDG PET/CT / 대한핵의학회잡지

PURPOSE@#This study evaluated the usefulness of semiquantitative and volumetric PET parameters for predicting prognosis in patients with advanced gastric cancer (AGC).@*METHODS@#We enrolled 213 patients who underwent ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) prior to curative surgery for AGC. Maximum standardized uptake value (SUVmax) and tumor-to-liver uptake ratio (TLR) were measured in all patients. Metabolic tumor volume (MTV) and total lesion glycolysis were measured in volume-measurable patients. For further quantification of FDG uptake, we developed PET prognostic scores by combining SUVmax and MTV (1: low SUVmax/low MTV; 2: high SUVmax/low MTV; 3: high SUVmax/high MTV). Comparison of PET parameters between recurrence and non-recurrence groups was performed. Univariate and multivariate analyses for recurrence-free survival (RFS) and overall survival (OS) were subsequently performed.@*RESULTS@#The recurrence rate was 32.4% (69/213 patients). Mean SUVmax and mean MTV of the recurrence group were significantly higher than those of the non-recurrence group (p = 0.026 and p = 0.025). TLR showed marginal significance (p = 0.051). In multivariate analysis for RFS including all patients, SUVmax (p = 0.022), TLR (p = 0.010), and PET score (p = 0.003) were independent prognostic factors. In post hoc analysis of PET score, significant differences in RFS were observed between PET scores 2 and 3 as well as scores 1 and 3. No significant difference in RFS was observed between scores 1 and 2. Only PET score was statistically significant for OS in univariate analysis. None of the PET parameters were statistically significant for OS in multivariate analysis.@*CONCLUSION@#High SUVmax and high MTV of the primary tumor suggest a high risk of recurrence for AGC patients. Even if SUVmax is similar, the prognosis may vary depending on MTV. Combining PET parameters results in a better prediction for prognosis.

Preoperative Nodal ¹⁸F-FDG Avidity Rather than Primary Tumor Avidity Determines the Prognosis of Patients with Advanced Gastric Cancer

PURPOSE: This study investigated whether the metabolic avidity of primary tumors and/or metastatic lymph nodes (LNs) measured by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) was related to survival after surgery in patients with advanced gastric cancer (AGC). MATERIALS AND METHODS: One hundred sixty-eight patients with AGC who underwent preoperative 18F-FDG PET/CT and curative resection were included. The 18F-FDG avidity of the primary gastric tumor and LNs was determined quantitatively and qualitatively. The diagnostic performance of 18F-FDG PET/CT was calculated, and the prognostic significance of 18F-FDG avidity for recurrence-free survival (RFS) and overall survival (OS) was assessed. RESULTS: In all, 51 (30.4%) patients experienced recurrence, and 32 (19.0%) died during follow-up (median follow-up duration, 35 months; range, 3–81 months); 119 (70.8%) and 33 (19.6%) patients showed 18F-FDG-avid primary tumors and LNs, respectively. 18F-FDG PET/CT showed high sensitivity (73.8%) for the detection of advanced pathologic T (pT ≥3) stage and high specificity (92.2%) for the detection of advanced pN (≥2) stage. 18F-FDG avidity of LNs was significantly associated with RFS (P=0.012), whereas that of primary tumors did not show significance (P=0.532). Univariate and multivariate analyses revealed that 18F-FDG avidity of LNs was an independent prognostic factor for RFS (hazard ratio=2.068; P=0.029). CONCLUSIONS: 18F-FDG avidity of LNs is an independent prognostic factor for predicting RFS. Preoperative 18F-FDG PET/CT can be used to determine the risk and prognosis of patients with AGC after curative resection.

Predictive Value of Preoperative Volume-Based 18F-2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography Parameters in Patients with Resectable Lung Adenocarcinoma / 대한핵의학회잡지

PURPOSE@#This study aimed to investigate the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG), which are volume-based PET parameters, using 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in patients with surgically resectable lung adenocarcinoma.@*METHODS@#We retrospectively evaluated 149 patients with lung adenocarcinoma who underwent 18F-FDG PET/CT before surgical resection. Maximum standardized uptake value (SUVmax), MTV, and TLG of the primary tumor with threshold value of SUVmax 30, 40, and 50% were calculated, respectively. To compare the predictive performance of volume-based PET parameters, recurrence-free survival was assessed using the Kaplan-Meier method.@*RESULTS@#The study included 70 males and 79 females with an average age of 65.8 years. The median follow-up time was 45.4 months. Recurrence was observed in 53 patients (35.6%). The mean ± SD SUVmax, MTV30%, and TLG(30%) of the entire cohort were 4.79 ± 2.94, 19.45 ± 24.85, and 56.43 ± 101.88, respectively. The cut-off values of MTV30% and TLG(30%) for recurrence were 11.07 ad 30.56, respectively. The 1-year recurrence-free survival (RFS) rate was 96.5% in low-MTV30% patients compared with 86.2% in high-MTV30% patients (p = 0.018) and 96.0% in low-TLG(30%) patients compared with 88.5% in high-TLG(30%) patients (p < 0.001). On univariate and multivariate analysis, TLG(30%) (HR, 2.828, p < 0.001; HR, 2.738, p < 0.001, respectively) was an independent prognostic factor for predicting recurrence-free survival (RFS).@*CONCLUSION@#TLG(30%) value was observed to be a significant prognostic factor for RFS in patients with lung adenocarcinoma treated by surgical resection.

Predictive Value of Preoperative Volume-Based 18F-2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography Parameters in Patients with Resectable Lung Adenocarcinoma / 대한핵의학회잡지

PURPOSE: This study aimed to investigate the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG), which are volume-based PET parameters, using 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in patients with surgically resectable lung adenocarcinoma.METHODS: We retrospectively evaluated 149 patients with lung adenocarcinoma who underwent 18F-FDG PET/CT before surgical resection. Maximum standardized uptake value (SUVmax), MTV, and TLG of the primary tumor with threshold value of SUVmax 30, 40, and 50% were calculated, respectively. To compare the predictive performance of volume-based PET parameters, recurrence-free survival was assessed using the Kaplan-Meier method.RESULTS: The study included 70 males and 79 females with an average age of 65.8 years. The median follow-up time was 45.4 months. Recurrence was observed in 53 patients (35.6%). The mean ± SD SUVmax, MTV30%, and TLG(30%) of the entire cohort were 4.79 ± 2.94, 19.45 ± 24.85, and 56.43 ± 101.88, respectively. The cut-off values of MTV30% and TLG(30%) for recurrence were 11.07 ad 30.56, respectively. The 1-year recurrence-free survival (RFS) rate was 96.5% in low-MTV30% patients compared with 86.2% in high-MTV30% patients (p = 0.018) and 96.0% in low-TLG(30%) patients compared with 88.5% in high-TLG(30%) patients (p < 0.001). On univariate and multivariate analysis, TLG(30%) (HR, 2.828, p < 0.001; HR, 2.738, p < 0.001, respectively) was an independent prognostic factor for predicting recurrence-free survival (RFS).CONCLUSION: TLG(30%) value was observed to be a significant prognostic factor for RFS in patients with lung adenocarcinoma treated by surgical resection.

Ratio of Mediastinal Lymph Node SUV to Primary Tumor SUV in ¹⁸F-FDG PET/CT for Nodal Staging in Non-Small-Cell Lung Cancer / 대한핵의학회잡지

PURPOSE: Following determination of the maximum standardized uptake values (SUVmax) of the mediastinal lymph nodes (SUV-LN) and of the primary tumor (SUV-T) on ¹⁸F-FDG PET/CT in patients with non-small-cell lung cancer (NSCLC), the aim of the study was to determine the value of the SUV-LN/SUV-T ratio in lymph node staging in comparison with that of SUV-LN.METHODS: We retrospectively reviewed a total of 289 mediastinal lymph node stations from 98 patients with NSCLC who were examined preoperatively for staging and subsequently underwent pathologic studies of the mediastinal lymph nodes. We determined SUV-LN and SUV-R for each lymph node station on ¹⁸F-FDG PET/CT and then classified each station into one of three groups based on SUV-T (low, medium and high SUV-T groups). Diagnostic performance was assessed based on receiver operating characteristic (ROC) curve analysis, and the optimal cut-off values that would best discriminate metastatic from benign lymph nodes were determined for each method.RESULTS: The average of SUV-R of malignant lymph nodes was significantly higher than that of benign lymph nodes (0.79±0.45 vs. 0.36±0.23, P<0.0001). In the ROC curve analysis, the area under the curve (AUC) of SUV-R was significantly higher than that of SUV-LN in the low SUV-T group (0.885 vs. 0.810, P= 0.019). There were no significant differences between the AUCs of SUV-LN and of SUV-R in the medium and high SUV-T groups. The optimal cut-off value for SUV-R in the low SUV-T group was 0.71 (sensitivity 87.5 %, specificity 85.9 %).CONCLUSIONS: The SUV-R performed well in distinguishing between metastatic and benign lymph nodes. In particular, SUV-R was found to have a better diagnostic performance than SUV-LN in the low SUV-T group.