A comparison study of dual-energy spectral CT and 18F-FDG PET/CT in primary tumors and lymph nodes of lung cancer

Özet

PURPOSEWe aimed to investigate whether there is a correlation between dual-energy spectral computed tomography (DESCT) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) parameters in primary tumor and metastatic lymphnodes in patients with newly diagnosed lung cancer.METHODSPrimary tumor and metastatic lymph nodes of 68 patients diagnosed with lung cancer wereevaluated retrospectively with 18F-FDG PET/CT and DESCT imaging. The histologic subtypeswere adenocarcinoma (n=29), squamous cell carcinoma (SCC) (n=26), small cell lung cancer (SCLC) (n=11), and large cell neuroendocrine cancer (LCNEC) (n=2). In terms of PET parameters, SUVmax, SUVmean, SULmax, SULmean, SULpeak, and normalized SUL values wereobtained for primary tumors and metastatic lymph nodes. In terms of DESCT parameters,maximum and mean iodine content (IC), normalized IC values, iodine enhancement (IE) andnormalized IE values were calculated.RESULTSWe found no correlation between DESCT and 18F-FDG PET/CT parameters in primary tumorsand metastatic lymph nodes. In addition, no correlation was found in the analysis performedin any of the histologic subgroups. In patients with a primary tumor <3 cm, there was a moderate negative correlation between the parameters SUVmax-ICmax (r= -0.456, p = 0.043),SUVmean-ICmax (r= -0.464, p = 0.039) SULmean-ICmax (r= -0.497, p = 0.026), SUVmax-ICmean(r= -0.527, p = 0.020), SULmean-ICmean (r= -0.499, p = 0.025), and SULpeak-ICmean (r= -0.488,p = 0.029).CONCLUSIONWe consider that DESCT and 18F-FDG PET/CT indicate different characteristics of the tumorsand should not supersede each other.