Han Eun Ji, O Joo Hyun, Yoo Ie Ryung, Kim Yeon Sil, Kim Min Sik, Kang Jin Hyoung, Choi Woo Hee
Department of Radiology, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, South Korea.
Hell J Nucl Med. 2017 May-Aug;20(2):134-140. doi: 10.1967/s002449910554. Epub 2017 Jul 12.
The aim of this study was to assess the diagnostic performance of fluorine-18-fluoro-2-deoxyglucose (F-FDG) positron emission tomography (PET)/computed tomography (CT) for locoregional recurrent/residual tumor in patients with head and neck cancer (HNC) who underwent previous radiotherapy (RT).
F-FDG PET/CT images from patients with HNC who previously underwent RT were retrospectively reviewed. Only cases with histological confirmation within 4 weeks of PET/CT imaging were included. Standardized uptake values were obtained for lesions and PET/CT findings were compared with histological results.
Of 181 cases, 114 (63%) were histologically confirmed as malignant and 67 (37%) as benign. The sensitivity, specificity, and accuracy of PET/CT were 93%, 64%, and 82%, respectively. Inflammation was the most common cause of false positives and small tumor volume and low F-FDG avidity were the causes of false negatives. PET/CT had 100% sensitivity and 56% specificity for detecting recurrent or residual disease within 12 weeks after RT and 93% sensitivity and 64% specificity, more than 12 weeks after RT. The frequency of false positives in PET/CT images within 12 weeks of RT was similar to the results obtained 12 weeks after RT (15% vs. 14%). False positives were more frequent in PET/CT cases after two-dimensional or three-dimensional conformal RT than in those after intensity-modulated RT, although not statistically significant (15% vs. 9%, p>0.05).
F-FDG PET/CT might aid the diagnosis of locoregional residual/recurrent tumors in patients with HNC previously treated with RT. Inflammation was the main cause of false positives regardless of the interval between RT and PET/CT, even several years after RT. Therefore, histological verification of positive PET/CT findings should be conducted during follow-up of HNC patients treated with RT.
本研究旨在评估氟-18-氟-2-脱氧葡萄糖（F-FDG）正电子发射断层扫描（PET）/计算机断层扫描（CT）对先前接受过放射治疗（RT）的头颈癌（HNC）患者局部区域复发/残留肿瘤的诊断性能。
对先前接受过RT的HNC患者的F-FDG PET/CT图像进行回顾性分析。仅纳入PET/CT成像后4周内有组织学确诊的病例。获取病变的标准化摄取值，并将PET/CT结果与组织学结果进行比较。
181例病例中，114例（63%）经组织学确诊为恶性，67例（37%）为良性。PET/CT的敏感性、特异性和准确性分别为93%、64%和82%。炎症是假阳性的最常见原因，肿瘤体积小和F-FDG摄取低是假阴性的原因。PET/CT对RT后12周内复发或残留疾病的检测敏感性为100%，特异性为56%；RT后超过12周的敏感性为93%，特异性为64%。RT后12周内PET/CT图像中的假阳性频率与RT后12周的结果相似（15%对14%）。二维或三维适形RT后的PET/CT病例中假阳性比调强放疗后的更常见，尽管无统计学意义（15%对9%，p>0.05）。
F-FDG PET/CT可能有助于诊断先前接受过RT的HNC患者的局部区域残留/复发肿瘤。无论RT与PET/CT之间的间隔如何，即使在RT后数年，炎症仍是假阳性的主要原因。因此，在接受RT治疗的HNC患者随访期间，应对PET/CT阳性结果进行组织学验证。
