Kim Hyun Jeong, Cho Arthur, Yun Mijin, Kim Young Tae, Kang Won Jun
Department of Nuclear Medicine, Yonsei University College of Medicine, 250 Seongsanno, Seodaemun-gu, Seoul, 120-752, Korea.
Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Institute of Women's Life Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Ann Nucl Med. 2016 Feb;30(2):104-13. doi: 10.1007/s12149-015-1037-8. Epub 2015 Nov 6.
Endometrial cancer is the most frequent cancer occurring in the female genital tract in the Western countries. Because surgical staging is currently the standard, noninvasive techniques that accurately identify lymph node (LN) metastases would be beneficial by reducing costs and complications. The purpose of our study is to compare the diagnostic accuracy of 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) with that of magnetic resonance imaging (MRI) for detecting LN metastases in the preoperative staging of endometrial cancer.
Two hundred eighty-seven consecutive patients with endometrial cancer underwent preoperative PET/CT and MRI for staging. The malignancy criteria for LNs were a short diameter of 1 cm or more by MRI and focally increased (18)F-FDG uptake by PET/CT. After evaluating PET/CT and MRI separately, morphologic and functional image findings were compared with the histological findings regarding LN metastasis for all patients. PET/CT and MRI images were classified on the basis of histological findings as true-positive, true-negative, false-positive, or false-negative. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated.
Histologic examination revealed LN metastases in 51 patients (17.8%). The maximal standardized uptake values (SUVmax) of the primary lesions by PET/CT ranged from 1.4 to 37.7, with a mean value of 9.3, whereas those of the metastatic LNs ranged from 2.0 to 22.5 with a mean of 7.3. On a per-patient basis, node staging resulted in sensitivities of 70.0% with (18)F-FDG PET/CT and 34.0% with MRI, and specificities of 95.4 % with PET/CT and 95.0% with MRI. The NPV of PET/CT was 94.3%, and that of MRI was 87.2%. On a lesion base analysis, sensitivity of PET/CT was 79.4% while that of MRI was 51.6%. In detecting distant metastasis, the sensitivity, specificity, accuracy, PPV, and NPV of PET/CT were 92.9, 98.9, 98.6, 81.3, and 99.6%, respectively.
Diagnostic performance of FDG PET/CT was better than MRI for detecting metastatic lymph nodes in patients with endometrial cancer both by patient basis and lesion basis analyses. Due to high NPV, FDG PET-CT could aid in selecting candidates for lymphadenectomy.
子宫内膜癌是西方国家女性生殖道最常见的癌症。由于手术分期是目前的标准，能够准确识别淋巴结（LN）转移的非侵入性技术将有助于降低成本和并发症。我们研究的目的是比较2-[(18)F]氟-2-脱氧-D-葡萄糖（(18)F-FDG）正电子发射断层扫描/计算机断层扫描（PET/CT）与磁共振成像（MRI）在子宫内膜癌术前分期中检测LN转移的诊断准确性。
287例连续的子宫内膜癌患者接受了术前PET/CT和MRI分期检查。LN的恶性标准为MRI显示短径≥1 cm以及PET/CT显示局部(18)F-FDG摄取增加。分别评估PET/CT和MRI后，将所有患者的形态学和功能影像表现与LN转移的组织学结果进行比较。根据组织学结果将PET/CT和MRI图像分类为真阳性、真阴性、假阳性或假阴性。计算敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和准确性。
组织学检查发现51例患者（17.8%）有LN转移。PET/CT显示的原发灶最大标准化摄取值（SUVmax）范围为1.4至37.7，平均值为9.3，而转移LN的SUVmax范围为2.0至22.5，平均值为7.3。以患者为基础，淋巴结分期时，(18)F-FDG PET/CT的敏感性为70.0%，MRI为34.0%；PET/CT的特异性为95.4%，MRI为95.0%。PET/CT的NPV为94.3%，MRI为87.2%。以病灶为基础分析时，PET/CT的敏感性为79.4%，MRI为51.6%。在检测远处转移方面，PET/CT的敏感性、特异性、准确性、PPV和NPV分别为92.9%、98.9%、98.6%、81.3%和99.6%。
无论是以患者为基础还是以病灶为基础分析，FDG PET/CT在检测子宫内膜癌患者转移淋巴结方面的诊断性能均优于MRI。由于NPV高，FDG PET-CT有助于选择淋巴结切除术的候选者。
