The Association between the Body Mass Index, Chronic Obstructive Pulmonary Disease and SUV of the Non-Tumorous Lung in the Pretreatment [ 18 F]FDG-PET/CT of Patients with Lung Cancer.

Background : A debate persists on the prognostic value of the pre-therapeutic standardized uptake value (SUV) of non-tumorous lung tissue for the risk assessment of therapy-related pneumonitis, with most studies lacking significant correlation. However, the influence of patient comorbidities on the pre-therapeutic lung SUV has not yet been systematically evaluated. Thus, we aimed to elucidate the association between comorbidities, biological variables and lung SUVs in pre-therapeutic [ 18 F]FDG-PET/CT. Methods : In this retrospective study, the pre-therapeutic SUV in [ 18 F]FDG-PET/CT was measured in non-tumorous areas of both lobes of the lung. SUV MEAN , SUV MAX and SUV 95 were compared to a multitude of patient characteristics and comorbidities with Spearman's correlation analysis, followed by a Bonferroni correction and multilinear regression. Results : In total, 240 patients with lung cancer were analyzed. An elevated BMI was significantly associated with increased SUV MAX (β = 0.037, p < 0.001), SUV MEAN (β = 0.017, p < 0.001) and SUV 95 (β = 0.028, p < 0.001). Patients with chronic obstructive pulmonary disease (COPD) showed a significantly decreased SUV MAX (β = -0.156, p = 0.001), SUV MEAN (β = -0.107, p < 0.001) and SUV 95 (β = -0.134, p < 0.001). Multiple other comorbidities did not show a significant correlation with the SUV of the non-tumorous lung. Conclusions : Failure to consider the influence of BMI and COPD on the pre-therapeutic SUV measurements may lead to an erroneous interpretation of the pre-therapeutic SUV and subsequent treatment decisions in patients with lung cancer.