Introduction: Dynamic positron emission tomography (PET) studies with 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) were performed in patients with advanced nonsmall cell lung cancer (NSCLC) who received palliative chemotherapy to evaluate the impact of full kinetic analysis and assess its value with regard to short or long survival.
Materials and methods: The evaluation includes 42 metastatic lesions in 14 patients with NSCLC. All patients received a combined chemotherapeutic protocol consisting of vinorelbin and oxaliplatin. The survival data served as reference for the PET data. All patients were examined before onset of chemotherapy and on day 15-21 after onset of the first cycle. The following parameters were retrieved from the dynamic PET studies: standardized uptake value (SUV), fractal dimension, two-compartment model with computation of k1, k2, k3, k4 (unit: 1/min), the fractional blood volume, and the FDG-influx according to Patlak was calculated using the formula (k1 x k3) / (k2 + k3). We used a two-group classification, namely, a short- and long-term survival group based on the median survival time (193 days) as a cutoff. A support vector machines (SVM) analysis was used for classification of the two a prior defined groups.
Results: The observed survival times varied from 40 to 392 days with a median survival time of 193 days. Most kinetic parameters demonstrated only small changes mostly declining after one cycle. The change in all kinetic parameters did not correlate to the survival-based classification. The change in SUV was significant between the first and second study (p = 0.006) but without an impact on the prediction of short or long survival. SVM-based analysis revealed the highest correct classification rate (CCR) between short and long survival for the combination of SUV and influx of the first study and SUV, influx, k2, and k4 of the second study with a CCR of 95.2%.
Conclusion: The results demonstrate that a full kinetic analysis of the FDG kinetics in NSCLC is helpful for the classification into short or long survival and may be used to identify those patients who may benefit from this palliative chemotherapeutic protocol.