Iuchi Toshihiko, Hatano Kazuo, Uchino Yoshio, Itami Makiko, Hasegawa Yuzo, Kawasaki Koichiro, Sakaida Tsukasa, Hara Ryusuke
Division of Neurological Surgery, Chiba Cancer Center, Chiba, Japan.
Division of Radiation Oncology, Tokyo Bay Advanced Imaging and Radiation Oncology Clinic, Makuhari, Chiba, Japan.
Int J Radiat Oncol Biol Phys. 2015 Sep 1;93(1):133-40. doi: 10.1016/j.ijrobp.2015.04.044. Epub 2015 May 8.
The purpose of this study was to retrospectively assess the feasibility of radiation therapy planning for glioblastoma multiforme (GBM) based on the use of methionine (MET) positron emission tomography (PET), and the correlation among MET uptake, radiation dose, and tumor control.
Twenty-two patients with GBM who underwent MET-PET prior to radiation therapy were enrolled. MET uptake in 30 regions of interest (ROIs) from 22 GBMs, biologically effective doses (BEDs) for the ROIs and their ratios (MET uptake:BED) were compared in terms of whether the ROIs were controlled for >12 months.
MET uptake was significantly correlated with tumor control (odds ratio [OR], 10.0; P = .005); however, there was a higher level of correlation between MET uptake:BED ratio and tumor control (OR, 40.0; P < .0001). These data indicated that the required BEDs for controlling the ROIs could be predicted in terms of MET uptake; BED could be calculated as [34.0 × MET uptake] Gy from the optimal threshold of the MET uptake:BED ratio for tumor control.
Target delineation based on MET-PET was demonstrated to be feasible for radiation therapy treatment planning. MET-PET could not only provide precise visualization of infiltrating tumor cells but also predict the required radiation doses to control target regions.
本研究的目的是回顾性评估基于甲硫氨酸（MET）正电子发射断层扫描（PET）的多形性胶质母细胞瘤（GBM）放射治疗计划的可行性，以及MET摄取、放射剂量和肿瘤控制之间的相关性。
纳入22例在放射治疗前接受MET-PET检查的GBM患者。比较22个GBM的30个感兴趣区域（ROI）的MET摄取、这些ROI的生物等效剂量（BED）及其比值（MET摄取:BED），根据ROI是否得到超过12个月的控制进行分析。
MET摄取与肿瘤控制显著相关（优势比[OR]，10.0；P = 0.005）；然而，MET摄取:BED比值与肿瘤控制之间的相关性更高（OR，40.0；P < 0.0001）。这些数据表明，可根据MET摄取预测控制ROI所需的BED；从肿瘤控制的MET摄取:BED比值的最佳阈值可计算出BED为[34.0×MET摄取]Gy。
基于MET-PET的靶区勾画被证明对放射治疗计划是可行的。MET-PET不仅可以提供浸润性肿瘤细胞的精确可视化，还可以预测控制靶区所需的放射剂量。
