Uptake Decrease of Proliferative PET Tracer 18FLT in Bone Marrow after Carbon Ion Therapy in Lung Cancer

Purpose The aim of this study was to investigate the change of 3'-[18F]fluoro-3'-deoxy-l-thymidine (18FLT) uptake in normal bone marrow (BM) after inevitable radiation. Procedures Twenty-one non-small cell lung cancer patients who received carbon ion radiotherapy (CIRT) were studied with 18FLT-positron emission tomography/computed tomography (PET/CT) at pre- and post-CIRT. Radiation dose was calculated by radiation planning. Irradiated BM was divided into three groups (30%). Results 18FLT uptake clearly decreased at >10% irradiated areas and mildly decreased at 30% areas. Conclusion 18FLT revealed that BM function decreased by small dose such as 4.2-4.4 GyE/1 fraction.