Gómez-Río Manuel, Rodríguez-Fernández Antonio, Ramos-Font Carlos, López-Ramírez Escarlata, Llamas-Elvira José Manuel
Nuclear Medicine Department, "Virgen de las Nieves", University Hospital, Avda/ Fuerzas Armadas, 2., 18014 Granada, Spain.
Eur J Nucl Med Mol Imaging. 2008 May;35(5):966-75. doi: 10.1007/s00259-007-0661-5. Epub 2008 Jan 3.
Reliable differential diagnosis between tumour recurrence and treatment-induced lesions is required to take advantage of new therapeutic approaches to recurrent gliomas. Structural imaging methods offer a high sensitivity but a low specificity, which might be improved by neurofunctional imaging. This study aimed to test the hypothesis that incorporation of 18-fluoro-deoxy-glucose positron emission tomography (FDG-PET) increases the accuracy of this differential diagnosis obtained with 201Tl chloride-single-photon emission computed tomography (201Tl-SPECT).
Seventy-six patients (mean age 47.72 +/- 16.19 years) under suspicion of glioma recurrence, 42% with low-grade and 58% with high-grade lesions, were studied by (201)Tl-SPECT and FDG-PET, reporting results under blinded conditions using visual analysis. Tumour was confirmed by histological confirmation (23 patients) or clinical and structural neuroimaging follow-up (mean of 2.6 years).
This population had a high disease prevalence (72%). Globally, highest sensitivity was obtained using 201Tl-SPECT assessed with MRI (96%) and highest specificity using FDG-PET + MRI (95%). FDG-PET appeared slightly better for confirming tumour recurrence, whereas 201Tl-SPECT was superior for ruling out possible recurrence (disease present in 38% of FDG-PET negative explorations). In the high-grade subgroup, there were no false-positive examinations (specificity: 100%), but sensitivity differed among techniques (201Tl-SPECT : 94%; 201Tl-SPECT + MRI: 97%; FDG-PET + MRI: 83%). In the low-grade subgroup, 201Tl-SPECT + MRI showed highest sensitivity (95%) and lowest posttest negative probability (9%); FDG-PET + MRI offered highest specificity (92%) with a posttest negative probability of 35%.
FDG-PET does not clearly improve the diagnostic accuracy of (201)Tl-SPECT, which appears to be a more appropriate examination for the diagnosis of possible brain tumour recurrence, especially for ruling it out.
为了利用针对复发性神经胶质瘤的新治疗方法，需要对肿瘤复发和治疗引起的病变进行可靠的鉴别诊断。结构成像方法灵敏度高但特异性低，而神经功能成像可能会提高其特异性。本研究旨在验证以下假设：联合使用18-氟-脱氧-葡萄糖正电子发射断层扫描（FDG-PET）可提高用氯化亚铊单光子发射计算机断层扫描（201Tl-SPECT）进行鉴别诊断的准确性。
对76例疑似神经胶质瘤复发的患者（平均年龄47.72±16.19岁）进行了研究，其中42%为低级别病变，58%为高级别病变。采用201Tl-SPECT和FDG-PET对患者进行检查，并在盲态条件下通过视觉分析报告结果。通过组织学确认（23例患者）或临床及结构神经影像学随访（平均2.6年）确诊肿瘤。
该人群疾病患病率较高（72%）。总体而言，使用MRI评估的201Tl-SPECT灵敏度最高（96%），而FDG-PET + MRI特异性最高（95%）。FDG-PET在确认肿瘤复发方面似乎稍好一些，而201Tl-SPECT在排除可能的复发方面更具优势（在FDG-PET阴性检查中，38%存在疾病）。在高级别亚组中，没有假阳性检查（特异性：100%），但不同技术的灵敏度有所不同（201Tl-SPECT：94%；201Tl-SPECT + MRI：97%；FDG-PET + MRI：83%）。在低级别亚组中，201Tl-SPECT + MRI灵敏度最高（95%），检验后阴性概率最低（9%）；FDG-PET + MRI特异性最高（92%），检验后阴性概率为35%。
FDG-PET并未明显提高201Tl-SPECT的诊断准确性，201Tl-SPECT似乎是诊断可能的脑肿瘤复发，尤其是排除复发的更合适检查方法。
