@article{oai:repo.qst.go.jp:00045492,
 author = {Koizumi, Mitsuru and Saga, Tsuneo and Yoshikawa, Kyosan and Suzuki, Kazutoshi and Yamada, Shigeru and Hasebe, Mitsuhiko and Ohashi, Seiya and Mahmoud, Abd-Elrazek Helmy Sherif and Ishikawa, Hiroyuki and Sagou, Kenji and Hara, Ryusuke and Katou, Hirotoshi and Yasuda, Shigeo and Yanagi, Takeshi and Tsujii, Hirohiko and et.al and 小泉 満 and 佐賀 恒夫 and 吉川 京燦 and 鈴木 和年 and 山田 滋 and 長谷部 充彦 and 大橋 靖也 and Ｓｈｅｒｉｆ Ｍａｈｍｏｕｄ Ａｂｄ−Ｅｌｒａｚｅｋ Ｈｅｌｍｙ and 石川 博之 and 佐合 賢治 and 原 竜介 and 加藤 博敏 and 安田 茂雄 and 柳 剛 and 辻井 博彦},
 issue = {6},
 journal = {Molecular Imaging and Biology},
 month = {Aug},
 note = {Purpose: Progress of the novel carbon ion radiotherapy (CIRT) in the treatment of cancers has created the need for a method to accurately evaluate the response. We investigated whether L-[11C]methyl-methionine (11C–methionine) uptake at pre- and post-CIRT could be an early response predictor in patients with pelvic recurrence of rectal cancer.
Patients and Methods: 11C–methionine positron emission tomography (PET) was performed prospectively in 53 patients with pelvic recurrence of rectal cancer before and 1 month after CIRT. 11C–methionine tumor uptake was measured by the tumor to muscle ratio (T/M ratio). The T/M ratios were evaluated in relation to clinical outcomes such as local re-recurrence, distant metastasis and survival. The response to CIRT was also judged by computed tomography (CT) and magnetic resonance imaging (MRI). 11C–methionine PET judgment was compared with CT/MRI judgment regarding the relevance to clinical outcome. 
Results: Baseline T/M ratio was 5.27±1.90 (mean±SD) in patients without developing local re-recurrence and 7.66±3.17 in patients with local re-recurrence (P=0.023, Mann-Whitney U test). Post-CIRT T/M ratios were 3.10±1.28 in patients without local re-recurrence and 6.15±2.98 in patients with local re-recurrence (p=0.006, Mann-Whitney U test). By Kaplan-Meier analysis with log-rank test, patients with a baseline T/M ratio of ≦7.6 or a post-CIRT T/M ratio of ≦5.0 had significant lower pelvic re-recurrence. However, the % change (reduction rate) from baseline to post-CIRT T/M ratio did not have significant relation to pelvic re-recurrence. There were no significant differences between 11C–methionine results (baseline T/M ratio, post-CIRT T/M ratio and % change) and other clinical parameters (distant metastasis and survival).
Conclusion: 11C–methionine PET can be used for early prediction of local re-recurrence after CIRT. Because CIRT is local therapy, 11C–methionine PET cannot predict distant metastasis or survival after CIRT.},
 pages = {374--380},
 title = {11C-Methionine-PET for Evaluation of Carbon Ion Radiotherapy in Patients with Pelvic Recurrence of Rectal Cancer},
 volume = {10},
 year = {2008}
}