摘要
目的比较3种FDG PET-CT勾画方法在食管癌GTV勾画中的差别,寻找GTV勾画的最佳SUV阈值,探讨FDG PET-CT在淋巴结检测中的作用。方法接受根治性食管癌切除术患者33例入组,除常规检查外均行PET-CT扫描。采用肉眼法、SUV2.5和40%SUVmax3种方法勾画肿瘤GTV,测量其纵轴长度后分别记为Lvis、L2.5和L40%。术后测量病理标本的长度,记为Lpath,并与PET-CT测量的长度比较。术后对PET重新阅片,采用不同的SUVmax百分数勾画GTV,当长度与Lpath一致时,该值为最佳SUV阈值。根据术后病理验证PET-CT对食管癌淋巴结转移诊断结果。结果病理长度(Lpath)为(5.52±2.00)cm,21个肿瘤长度≥5cm,12个肿瘤〈5cm。Lvis、L2.5和L40%值分别为(5.16±1.97)、(5.55±1.81)和(4.42±1.60)cm,与Lpath的相关系数分别为0.817、0.877和0.863。L40%显著小于Lpath(P〈0.001)。在所有肿瘤中最佳SUV阈值为24.30%±10.96%,在长度≥5cm的肿瘤中为21.14%±9.06%,〈5cm的为29.83%±12.15%。最佳SUV阈值与L/B比值和Lpath的相关系数分别为-0.730、-0.515。对淋巴结检测的敏感性、特异性和准确性分别为77.8%、95.2%和92.3%。结论不同方法勾画的肿瘤长度不同。L2.5勾画的结果与病理长度一致性最好。最佳SUV阈值与L/B比值和肿瘤长度呈负相关。FDG PET-CT能够较准确地检测转移淋巴结。
Objective To compare the gross tumor volumes (GTVs) delineated with 3 different methods on FDG PET imaging, to find the optimal threshold of GTV delineation for esophageal cancer, and to evaluate the accuracy of FDG PET-CT in the detection of lymph node metastasis. Methods Thirty-three patients with esophageal squamous cell cancer treated with radical surgery were enrolled. All patients underwent a pretreatment evaluation and a FDG PET-CT scan. GTV was delineated with 3 different methods ( visual interpretation, SUV 2.5 and 40% SUVmax ) on FDG PET imaging. The longitudinal length of tumors was measured and recorded as Lvis, L2.5 and L40% , respectively. The length of surgical specimen measured by pathological examination was recorded as Lpath and compared with the length of PET scan. All PET data were reviewed again postoperatively, and the GTV was delineated using various percentages of SUVmax. The optimal threshold SUV was generated when the length of PET matched the Lpath. The diagnosis of PET-CT for lymph node metastasis was validated with the pathological result. Results The mean Lpath was 5.52 ± 2.00 cm. There were 21 tumors equal to or more than 5 cm and 12 tumors less than 5 cm. The mean Lvis, L2.5 and L40% were 5.16 ± 1.97 cm, 5.55 ± 1.81 cm and 4.42 ± 1.60 cm. The correlation coefficients were 0.817, 0.877 and 0. 863 when compared with Lpath, respectively. The mean L40% was significantly shorter than Lpath (P 〈 0.001 ). The mean optimal threshold was 24.30% ± 10.96% for all tumors. The value was 21.14% ±9.06% for tumor 〉15 cm and 29.83% ± 12.15% for tumor 〈5 cm. The correlation coefficient of the optimal threshold was- 0.730 with lesion/background (L/B) and -0. 515 with Lpath. The sensitivity, speeifieity and accuracy of FDG PET-CT in the deteetion of lymph node metastasis were 77.8% , 95.2% and 92.3%, respectively. Conclusions Different methods used in target volume delineation on PET scan yield different tumor length, and the L2.5 is elosely eonsistent with the Lpath. The optimal threshold is inversely correlated with L/B and tumor length. FDG PET-CT is accurate for evaluating metastasis to individual lymph node groups.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2008年第1期22-25,共4页
Chinese Journal of Radiation Oncology
基金
国家自然科学基金资助项目(30700196)
山东卫生厅医药卫生科技发展计划资助项目(2005HW137)