18F-氟化钠PET和PET-CT诊断肺癌骨转移的对比研究

目的 对比研究18F-氟化钠(18F-NaF)PET和PET-CT对肺癌骨转移诊断的准确性.方法 34例初始诊断为肺癌的患者接受18F-NaF PET-CT检查,对PET和PET-CT图像分别进行解释,发现的病变分为恶性、良性和不确定三种.骨转移的综合评价方法包括MRI(34例)、18F-氟脱氧葡糖糖PET-CT(4例)、组织学活检(2例)和临床随访(6例).结果 按患者水平分析时,34例患者中的11例(32%)发生骨转移,其中,18F-NaF PET-CT准确诊断所有患者的骨转移,无假阳性和假阴性,而18F-NaF PET诊断真阳性8例、3例不能确定,18F-NaF PET确诊的8例骨转移患者中的4例PET没有显示全部转移病变(假阴性和不确定病变);按病变水平分析时,118个病变获得最终诊断,其中转移病变47个、良性病变71个,其中,18F-NaF PET诊断真阳性27个、真阴性64个、不确定病变24个、假阴性1个、假阳性2个,而18F-NaF PET-CT诊断真阳性46个、假阴性1个、真阴性71个.按患者水平分析,将不确定病变归为恶性时,18F-NaF PET-CT的特异性高于18F-NaF PET(100% vs 78%,χ2=10.78,P<0.05),二者的灵敏度均为100%;将不确定病变归为良性时,18F-NaF PET-CT诊断骨转移的灵敏度显著高于18F-NaF PET(100% vs 73%,χ2=6.41,P<0.01),二者特异度差异无显著性(100% vs 96%,χ2=2.03,P>0.05);按病变水平分析时,得到与患者水平分析相似结果.结论 18F-NaF PET-CT诊断肺癌骨转移的准确性优于18F-NaF PET,PET-CT中的低剂量CT可进一步提高良、恶性病变的鉴别能力.

Comparison between 18F-NaF PET and PET-CT to detect bone metastases in patients with lung cancer

Objective To evaluate the effect of 18F-sodium fluoride(18F-NaF)PET-CT in the detection of bone metastases in patients with lung cancer.Methods Thirty-four patients with newly diagnosed lung cancer were performed with 18F-NaF PET-CT.18F-NaF PET and 18F-NaF PET-CT were interpreted separately.Lesions were categorized as malignant,benign or inconclusive.A panel of reference methods was used,including MRI(34 patients),18F-fluorodeoxyglucose PET-CT(4 patients),histopathology(2 patients),or clinical follow-up of at least 6 months(6 patients).Results In patient-based analysis,11 of 34 patients had bone metastases.18F-NaF PET-CT correctly diagnosed all 11 patients with bone metastases,18F-NaF PET only correctly detected 8 of them.18F-NaF PET-CT had no false and inconclusive diagnosis.In lesion-based analysis,118 lesions were assessed which had final diagnosis(47 metastases,71 benign lesions).18F-NaF PET-CT was correct in 46 metastatic lesions and 71 benign lesions,but false-negative in lesion.18F-NaF PET was correct in 27 metastatic lesions and 64 benign lesions,but wrong in 3 lesions(2 benign lesions,1 metastatic lesions),and equivocal in 24 lesions.Based on the corresponding appearance on low-dose CT,46 of 47 lesions were categorized metastases(31 presented as sites of increased uptake with corresponding lytic or sclerotic changes,and other 15 metastases show normal or non-specific appearing bone),only 1 sclerotic metastasis was judged benign. All 71 benign lesions have a benign appearance on low-dose CT. In patient-based analysis, categorizing equivocal and malignant interpretation as suggestive for malignancy, the 18F-NaF PET-CT was more specific than 18F-NaF PET(100% vs 78%, χ2=10.78, P<0.05), the sensitivity was 100% for each other. Categorizing equivocal and benign as benignity, the 18F PET-CT was more sensitive than 18F-NaF PET (100% vs 73%, χ2=6.41, P<0.001), the specificity between them was not significantly (100% vs 96%,χ2=2.03, P>0.05). In lesion-based analysis, the similar results were obtained as patient-based analysis.Conclusion 18F-NaF PET-CT was both sensitive and specific for detection of bone metastases in patients with newly diagnosed lung cancer. With the diagnosis information of low-dose CT, its ability of differentiation between malignant and benign lesions is improved.