Evaluation of the Relationship Between SUVmax Measured on F-18 FDG PET/CT, Disease Stage, and Serum Tumor Markers in Colorectal Adenocarcinomas
Zeynep Akar1, Ali Şahin21Department of Nuclear Medicine, Balikesir Ataturk City Hospital, Balikesir, Türkiye, 2Department of Nuclear Medicine, Faculty of Medicine, Ataturk University, Erzurum, Türkiye
Objectives: This study aimed to investigate the relationship between the maximum standardized uptake value (SUVmax) measured by Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) and disease stage, presence of distant metastasis, and serum tumor markers in patients with colorectal adenocarcinoma. Methods: This retrospective study included 92 patients with histopathologically confirmed colorectal cancer who underwent F-18 FDG PET/CT for staging purposes between January 1, 2005, and February 1, 2015. Demographic characteristics, clinical nodal status, histopathological findings, serum tumor markers.[carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9)], and complete blood count parameters were recorded. Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), and systemic immune-inflammatory index (SII) were calculated from peripheral blood counts. SUVmax values were determined for the primary tumor in PET/ CT images, and the presence of metastasis was evaluated. The diagnostic performance of parameters in predicting metastasis was examined using receiver operating characteristic (ROC) curve analysis, and related factors were evaluated using univariate and multivariate logistic regression analyses. Results: Of the patients, 66.3% were male, and 47.8% had stage 4 disease. In ROC analysis, the area under the curve (AUC) for primary tumor SUVmax was 0.667 (p=0.006) with a cut-off of 11.24 for predicting metastasis. CA19-9 (AUC: 0.707; p=0.001), NLR (AUC: 0.705; p=0.001), PLR (AUC: 0.646; p=0.016), and SII (AUC: 0.736; p<0.001) were significantly associated with metastasis. In univariate analysis, patients with positive lymph nodes had approximately a 7-fold increased risk of metastasis (OR: 7.18; p<0.001). SUVmax >= 11.24 (OR: 2.82; p=0.018), CA19-9 >= 89.8 (OR: 2.38; p=0.048), NLR >= 3.84 (OR: 5.47; p<0.001), PLR >= 238.3 (OR: 3.22; p=0.007), and SII >= 1462.1 (OR: 7.09; p<0.001) were identified as predictive factors for metastasis. In patients with LMR >= 0.25, an inverse relationship with metastasis was observed (OR: 0.21; p=0.001). In multivariate analysis, clinical nodal positivity (OR: 11.20; p<0.001), primary tumor SUVmax >= 11.24 (OR: 6.26; p=0.003), and SII >= 1462.1 (OR: 13.84; p<0.001) were identified as independent predictive factors for the presence of metastasis. Conclusion: In colorectal cancer patients, the primary tumor SUVmax value obtained from F-18 FDG PET/CT, when evaluated together with systemic inflammation markers and clinical nodal status, significantly contributes to predicting the presence of distant metastasis. In particular, the combined use of SUVmax and SII may provide valuable clinical guidance in preoperative risk stratification and treatment planning. Keywords: Colorectal adenocarcinoma,
Cite This Article
Akar Z, Şahin A. Evaluation of the Relationship Between SUVmax Measured on F-18 FDG PET/CT, Disease Stage, and Serum Tumor Markers in Colorectal Adenocarcinomas. EJMI. 2026; 10(3): 296-302
Corresponding Author: Zeynep Akar