Mapping Bone Marrow Response in the Vertebral Column by Positron Emission Tomography Following Radiotherapy and Erlotinib Therapy of Lung Cancer

Purpose To map functional bone marrow (BM) by 2-deoxy-2-[ 18 F]fluoro- d -glucose ([ 18 F]FDG) positron emission tomography (PET) in the vertebral column of lung cancer patients prior to, during, and after treatment. Moreover, to identify radiation- and erlotinib-induced changes in the BM. Procedures Twenty-six patients with advanced non-small cell lung cancer, receiving radiotherapy (RT) alone or concomitantly with erlotinib, were examined by [ 18 F]FDG PET before, during, and after treatment. A total of 61 [ 18 F]FDG PET scans were analyzed. Vertebral column BM [ 18 F]FDG standardized uptake value normalized to the liver (SUV BMLR ) was used as uptake measure. Wilcoxon signed-rank test was used to assess changes in BM uptake of [ 18 F]FDG between sessions. Effects of erlotinib on the BM activity during and after treatment were assessed using Mann-Whitney U test. Results A homogeneous uptake of [ 18 F]FDG was observed within the vertebral column prior to treatment. Mean SUV BMLR (± S.E.M) in the body of thoracic vertebrae receiving a total RT dose of 10 Gy or higher was 0.64 ± 0.01, 0.56 ± 0.01, and 0.59 ± 0.01 at pre-, mid-, and post-therapy, respectively. A significant reduction in the mean SUV BMLR was observed from pre- to both mid- and post-therapy ( p