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 (SUVBMLR ) 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 SUVBMLR (± 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 SUVBMLR was observed from pre- to both mid- and post-therapy (p < 0.05). Mean SUVBMLR was significantly higher at post-therapy compared to mid-therapy for patients receiving erlotinib in addition to RT (p < 0.05).

CONCLUSIONS: RT reduces BM [18 F]FDG uptake in the vertebral column, especially in the high-dose region. Concomitant erlotinib may stimulate a recovery in BM [18 F]FDG uptake from mid- to post-therapy.

TRIAL REGISTRATION: NCT02714530. Registered 10 September 2015.