Relations between the standardized uptake value of 18F-FDG-PET/CT and demographic, clinical, pathological, and radiological factors in lung cancer

Background FDG-PET/CT is considered a noninvasive method for mediastinal staging and functional assessment of lung cancer. Standardized uptake value maximum (SUVmax) estimates the activity of the tumor and its aggressiveness. Aim To measure the relation of clinical, demographic, radiological factors, histopathology, and SUVmax in patients of bronchogenic carcinoma. Patients and methods The study was a prospective cross-sectional study on 47 confirmed lung cancer patients admitted to the Chest Department of Ain Shams University Hospital from April 2022 to May 2023. Demographic data, clinical examination, complete blood count, tumor site and size in CT chest or PET-CT, histopathology, and SUVmax values in PET-CT scans with staging according to the 8th TNM system were done. SUVmax relation with all parameters was done. Results In this study, the relation between age, smoking habits ( P =0.60), comorbidities ( P =0.18), and tumor SUVmax was not significant. No relation between tumor characteristics: site ( P =0.27), histopathology ( P =0.46), extrapulmonary metastases including mediastinal lymph node ( P =0.09), and tumor SUVmax. Positive significant correlation between tumor size, T staging, and tumor SUVmax. No correlation between age, pack year, N staging, M staging, TNM staging, and tumor SUVmax. No significant correlation was found between laboratory tests: TLC count, HB count, platelet count, and tumor SUVmax. No relation between tumor histopathology and tumor site ( P =0.32), with no significant relation between tumor histopathology and patients age ( P =0.77), pack year ( P =0.89), or tumor size ( P =0.07). Conclusion Tumor size and T staging positively correlated with SUVmax. SUVmax was higher in squamous cell carcinoma patients with no statistically significant relation.