PET imaging of [11C]docetaxel uptake and tumor perfusion in lung cancer.

Abstract

2543 Background: Although docetaxel is an effective treatment of lung cancer, a number of patients do not benefit from this therapy due to tumor resistance. Positron emission tomography (PET) is a noninvasive imaging technique that allows for quantification of radiolabeled docetaxel ([11C]docetaxel) kinetics and might be useful for predicting response to treatment. The aim of the present study was to determine the feasibility and reproducibility of [11C]docetaxel PET scans in lung cancer and to investigate whether [11C]docetaxel uptake was related to tumor perfusion. Methods: Fourteen patients with advanced lung cancer underwent a dynamic PET-CT scan with [11C]docetaxel (60 min) and H215O (10 min). In addition, patients underwent a second [11C]docetaxel PET scan to assess test-retest reproducibility. Lesions were delineated on the CT scan and projected onto the dynamic PET frames. [11C]docetaxel uptake in tumors was quantified using the net influx rate (Ki). Tumor perfusion was quantified by applying the standard single tissue compartment model to the H215O data. Results: In total, 24 lesions were defined, including both primary tumors and metastases. Clearance of [11C]docetaxel from plasma was rapid and later PET frames suffered from high liver uptake. Therefore, only the first 10 min of data were used for further analysis. The median net influx rate of [11C]docetaxel was 0.009 min-1 (range, 0.000-0.022). [11C]docetaxel PET scans showed good reproducibility (intraclass correlation coefficient, 0.89). The inter- and intra-individual variability of [11C]docetaxel uptake in lesions was high. [11C]docetaxel uptake was correlated with tumor perfusion (r=0.853, p<0.001). Conclusions: Measurement of [11C]docetaxel uptake in lung cancer is feasible with good reproducibility. [11C]docetaxel uptake depends on tumor perfusion. The variability of [11C]docetaxel uptake in lung cancer lesions may reflect differential sensitivity to docetaxel treatment, suggesting that PET scans with [11C]docetaxel may be useful for personalized treatment planning. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Philips Healthcare