@misc{oai:repo.qst.go.jp:00069909,
 author = {Koizumi, Mitsuru and Saga, Tsuneo and Inubushi, Masayuki and Yoshikawa, Kyosan and Fukumura, Toshimitsu and Baba, Masayuki and 小泉 満 and 佐賀 恒夫 and 犬伏 正幸 and 吉川 京燦 and 福村 利光 and 馬場 雅行},
 month = {Oct},
 note = {Aim: In the radiation therapy, normal bone marrow is often included in radiation field inevitably. The aim of this study was to investigate the change in 3'-18F-fluoro-3'-deoxy-L-thymidine (FLT) uptake to normal bone marrow after inevitable radiation.
Methods: Twenty-one non-small cell lung cancer (NSCLC) patients who received carbon ion radiotherapy (CIRT) were studied with regard to bone marrow activity by FLT PET/CT. CIRT was performed with three protocols (42-44 GyE/1 fraction in 9 patients, 52.8-60 GyE/4 fractions in 10 patients, and 62.8 GyE/12 fractions in 2 patients). These dose and fraction pairs gave the similar clinical tumor response results. Radiation dose to bone marrow was calculated by three dimensional CT planning system. FLT PET/CT studies were carried out before and after CIRT. Post-CIRT FLT studies were performed at 1 or 2 day after CIRT (6 patients), 3 months after CIRT (20 patients) and more than 1 year after CIRT (3 patients). FLT uptake was evaluated visually and by a maximum standard uptake value (SUVmax). In some evaluations, the ratio of uptake of irradiated marrow to non-irradiated counterpart was used. As non-irradiated control sites, changes in lumbar (L2-5) bone marrow FLT uptake were measured. Irradiated bone marrow was divided into 2 two groups (10-30 % of maximum dose, and more than 30% of maximum dose), and the changes of FLT uptake were measured.
Results: Ribs were included in the radiation field in all patients; spine in 2 patients, scapula in 7 patients, and sternum in 2 patients. FLT uptake in the bone marrow receiving the 10 % dose or more clearly decreased at all time points after CIRT in comparison with pre-irradiation values. The FLT uptake was the lowest just after CIRT, somewhat recovered at 3 months, and remained unchanged for more than 1 year. There was no significant difference in reduction of FLT uptake between the area receiving 10-30% dose and those receiving more than 30%. FLT uptake to non-irradiated areas (L2-5) was not changed after CIRT.
Conclusion: Bone marrow receiving as low as 10% dose of carbon ion showed clearly decreased FLT uptake. Bone marrow cells are considered sensitive to low dose. FLT-PET can sensitively detect these changes and may help to confirm the radiation field., Annual Congress of the European Association of Nuclear Medicine 2009},
 title = {Evaluation of Bone Marrow Activity after Carbon-Ion Radiotherapy by PET/CT Using a Proliferative Tracer, FLT},
 year = {2009}
}