Prognostic value of different standard uptake values (SUV) of primary tumor measured with FDG-PET in resectable non-small cell lung cancer

Abstract

7214 Background: The SUV is a measure for the preferential uptake of a radiopharmaceutical in a tumor compared with a homogenous distribution in a body. SUV can be based on the maximum value (SUVmax) or on the mean value in a region outlined by isodensity contours, e.g., 70% and 50%. The prognostic value of the different SUVs in non-small cell lung cancer (NSCLC) is not clear. We evaluated the prognostic value of SUVmax, SUV 70% and SUV 50% in patients (pts) with resectable NSCLC. Methods: All consecutive pts who underwent an attenuation corrected whole body FDG-PET scan were selected. All data were reconstructed iteratively. Only pts with stage I through IIIA NSCLC were included. By adjusting the isocontour in the region of interest, the SUVmax, SUV 70% and SUV 50% of the primary tumor were calculated. Cox regression analysis was used to calculate the relation between the different SUVs and survival. Results: Eighty-four pts (67 males, median age 64 years, range 38–86) were included. Histology was squamous cell carcinoma (n = 43), adenocarcinoma (n = 27), large cell carcinoma (n = 13), and 1 patient with bronchoalveolar carcinoma. Nineteen pts had stage IA, 28 stage IB, 4 stage IIA, 19 stage IIB, and 14 stage IIIA. Median (range) SUVmax, SUV 70%, and SUV 50% were 6.9 (1.6–32.5), 5.5 (1.0–23.2), and 4.5 (0.9–21.9), respectively. Analysis of residuals of SUVmax as a continuous variable suggests no cut-off point and no indication of time-dependency. By univariate analysis, all pts with a SUV higher than the median value had a worse survival than pts with a SUV lower than median (Hazard ratio’s for SUVmax, SUV70% and SUV 50% were 2.3 (p = 0.024), 2.5 (p = 0.015), and 2.7 (p = 0.010), respectively). Conclusions: SUVmax, SUV 70% and SUV 50% measured with FDG-PET have a similar prognostic impact. No cut-off point for SUVmax has been observed. No significant financial relationships to disclose.