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 (<10% of maximum dose, 10-30%, and >30%).
Results: ¹⁸FLT uptake clearly decreased at >10% irradiated areas and mildly decreased at <10% areas. ¹⁸FLT uptake was lowest just after CIRT, somewhat increased at 3 months, and remained unchanged for more than 1 year. There was no significant difference between 10-30% and >30% areas.
Conclusion: ¹⁸FLT revealed that BM function decreased by small dose such as <4.2-4.4 GyE/1 fraction of CIRT and is eradicated by >4.2-4.4 GyE/1 fraction.