Cicuendez Marta, Lorenzo-Bosquet Carles, Cuberas-Borrós Gemma, Martinez-Ricarte Francisco, Cordero Esteban, Martinez-Saez Elena, Castell-Conesa Joan, Sahuquillo Juan
Department of Neurosurgery, Universitat Autònoma de Barcelona, Hospital Vall d'Hebron, Barcelona, Spain.
Department of Nuclear Medicine, Universitat Autònoma de Barcelona, Hospital Vall d'Hebron, Barcelona, Spain.
Clin Neurol Neurosurg. 2015 Dec;139:328-33. doi: 10.1016/j.clineuro.2015.10.035. Epub 2015 Nov 4.
[(11)C] methionine (MET) positron-emission tomography (PET) is a useful diagnostic and therapeutic tool in neuro-oncology. The aim of this study was to evaluate the relationship between MET uptake and the histopathological grade in both primary brain tumours and brain metastases. A secondary goal was to assess the relationship between MET uptake and patients' survival after surgery.
We reviewed a consecutive series of 43 PET studies performed at our institution. Out of the 43 patients studied, 35 harboured primary brain tumours (3 grade I, 12 grade II, 7 grade III and 13 grade IV) and 8 patients had brain metastases. We measured the tumour/cortex ratio (T/C ratio) on each PET study and we investigated the correlations among the tracer uptake, tumour grade, tumour type, MRI parameters and outcome.
The mean T/C ratio was 1.8 ± 0.9 for benign lesions and low grade gliomas (grade I and II) and 2.7 ± 1 for high grade gliomas (grade III and IV). In brain metastases it was 2.5 ± 0.7, with a significant difference in MET uptake between low and high grades gliomas (P=0.03). There was no statistically significant difference among all different histologic types. We found that both contrast enhancement and perfusion studies correlate with MET uptake in brain tumours. Moreover, in Kaplan-Meier curves, the T/C ratio adversely affects long term survival in patients with brain tumours (P=0.01).
MET PET appears to be useful in diagnosis and evaluation of potential malignancy in brain tumours. MET uptake is also related with the overall survival in patients with brain tumours. Nevertheless, further studies are needed in order to define its possible clinical implications in identifying patients at high risk of tumour progression or resistance to therapy.
[11C]蛋氨酸（MET）正电子发射断层扫描（PET）是神经肿瘤学中一种有用的诊断和治疗工具。本研究的目的是评估原发性脑肿瘤和脑转移瘤中MET摄取与组织病理学分级之间的关系。第二个目标是评估MET摄取与患者术后生存之间的关系。
我们回顾了在我们机构进行的连续43项PET研究。在研究的43例患者中，35例患有原发性脑肿瘤（3例I级、12例II级、7例III级和13例IV级），8例患者有脑转移瘤。我们在每项PET研究中测量肿瘤/皮质比值（T/C比值），并研究示踪剂摄取、肿瘤分级、肿瘤类型、MRI参数和结果之间的相关性。
良性病变和低级别胶质瘤（I级和II级）的平均T/C比值为1.8±0.9，高级别胶质瘤（III级和IV级）为2.7±1。在脑转移瘤中为2.5±0.7，低级别和高级别胶质瘤之间的MET摄取有显著差异（P=0.03）。所有不同组织学类型之间无统计学显著差异。我们发现，对比增强和灌注研究均与脑肿瘤中的MET摄取相关。此外，在Kaplan-Meier曲线中，T/C比值对脑肿瘤患者的长期生存有不利影响（P=0.01）。
MET PET似乎有助于脑肿瘤的诊断和潜在恶性程度的评估。MET摄取也与脑肿瘤患者的总生存相关。然而，需要进一步研究以确定其在识别肿瘤进展或治疗耐药高风险患者方面可能的临床意义。
