Semiquantitative analysis of C-11 methionine PET may distinguish brain tumor recurrence from radiation necrosis even in small lesions
Semiquantitative analysis of C-11 methionine PET may distinguish brain tumor recurrence from radiation necrosis even in small lesions
复制标题
DOI：
10.1007/s12149-010-0450-2
复制
发表时间：
2011-04-01
影响因子：
2.6
通讯作者：
Tamaki, Nagara
中科院分区：
文献类型：
--
作者：
Okamoto, Shozo;Shiga, Tohru;Tamaki, Nagara
（11）C-甲硫氨酸正电子发射断层扫描（MET-PET）已被用于区分脑肿瘤复发与放射性坏死。由于传统PET扫描仪的空间分辨率较低，部分容积效应（PVE）可能会降低小肿瘤复发的检出率。本研究的目的是调查MET-PET的诊断价值后半定量分析，特别是PVE影响的小lesions.First，我们进行了一个幻影实验，调查什么大小的病变是受PVE。本研究纳入了29例（33处病变）放射治疗后通过磁共振成像（MRI）疑似复发性脑肿瘤的患者。他们都接受了MET-PET。采用最大标准化摄取值（SUVmax）和病变与正常比值（L/N比值）进行半定量分析。ROC曲线分析MET-PET的诊断价值，根据体模实验结果，脑模式下小于20 mm或全身模式下小于30 mm的病灶定义为PVE受累病灶。组织学分析或临床随访证实22个病灶肿瘤复发，11个病灶放射性坏死。总病变的复发和坏死的L/N比值分别为1.98 ± 0.62和1.27 ± 0.28（p < 0.01）。在PVE受累的病变中，复发的L/N比值（1.72 +/-A0.44）也显著高于坏死的L/N比值（1.20 +/-A0.11）（p < 0.01）。在PVE受累病变的ROC分析中，L/N比值的曲线下面积（0.897）显著高于SUVmax（0.718）（p < 0.05）。L/N比值（0.886）和SUVmax（0.738）的曲线下面积几乎等于整个病变的曲线下面积。MET的半定量分析即使对PVE影响的小病变也提供了高诊断价值。MET-PET可以在放射治疗后的随访中早期诊断脑肿瘤的复发。
(11)C-Methionine positron emission tomography (MET-PET) has been used to distinguish brain tumor recurrence from radiation necrosis. Because the spatial resolution of conventional PET scanners is low, partial volume effect (PVE) may decrease the detectability of small tumor recurrence. The aim of this study is to investigate the diagnostic value of MET-PET upon semiquantitative analyses in particular PVE-affected small lesions.First, we performed a phantom experiment to investigate what size lesion is affected by PVE. This study included 29 patients (33 lesions) suspected of recurrent brain tumors by magnetic resonance imaging (MRI) after radiation therapy. All of them received MET-PET. Semiquantitative analysis was performed using maximum standardized uptake value (SUVmax) and lesion-versus-normal ratio (L/N ratio). ROC analysis was also assessed about the diagnostic value of MET-PET.From the result of the phantom experiment, lesions smaller than 20 mm in brain mode or smaller than 30 mm in whole-body mode were defined as PVE-affected lesions. Histological analysis or clinical follow-up confirmed the diagnosis of tumor recurrence in 22 lesions, and radiation necrosis in 11 lesions. L/N ratios of recurrence and necrosis for overall lesions were 1.98 +/- A 0.62 and 1.27 +/- A 0.28, respectively (p < 0.01). In the PVE-affected lesions, L/N ratio for recurrence (1.72 +/- A 0.44) was also significantly higher than that for necrosis (1.20 +/- A 0.11) (p < 0.01). On the ROC analysis for the PVE-affected lesions, the area under the curve for L/N ratio (0.897) was significantly higher than that for SUVmax (0.718) (p < 0.05). These areas under the curve were almost equal to that of overall lesions for L/N ratio (0.886) and for SUVmax (0.738).Semiquantitative analysis of MET provided high diagnostic value even for PVE-affected small lesions. MET-PET enables early diagnosis of recurrence of brain tumor in the follow-up after the radiation therapy.