Little Sherard G, Rice Thomas W, Bybel Bohdan, Mason David P, Murthy Sudish C, Falk Gary W, Rybicki Lisa A, Blackstone Eugene H
Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Cleveland, OH 44195, USA.
Eur J Cardiothorac Surg. 2007 May;31(5):791-6. doi: 10.1016/j.ejcts.2007.01.037. Epub 2007 Mar 2.
To ascertain whether fluorodeoxyglucose positron emission tomography is indicated for clinical staging of superficial cancer, we sought to determine if it accurately classifies tumor (T), regional nodal (N), and distant metastases (M), including distinguishing high-grade dysplasia (Tis) from invasive cancer (T1).
Fifty-eight superficial esophageal cancer patients had preoperative positron emission tomography, 53 (91%) fused with computed tomography. Tumor characteristics, esophagoscopy findings, and pTNM were compared with positron emission tomography cTNM. pT1 was subdivided into intramucosal cancers with lamina propria or muscularis mucosa invasion and submucosal cancers with inner or outer invasion.
Fluorodeoxyglucose uptake increased with pT, from 5/11 (45%) for pTis to 11/16 (69%) for pT1 (outer submucosa), P=0.07, as it did for standardized uptake value, median 0 for pTis to 2.7 for pT1 (outer submucosa), P=0.06. Positron emission tomography could not differentiate Tis (5/11, 45%) from T1 (26/47, 55%; P=0.03). Regional nodal fluorodeoxyglucose uptake in three patients (standardized uptake value 2.8, 4.9, 11) was false positive; in six pN1 patients, it was false negative. Positron emission tomography had 0% sensitivity and positive predictive value for N1. There were no distant metastases; one patient developed a pulmonary metastasis 15 months postoperatively. Positron emission tomography detected three (5%) distant hypermetabolic sites, all synchronous tumors (papillary thyroid cancer, adrenal pheochromocytoma, rectal adenoma). Only increasing tumor length was related to greater fluorodeoxyglucose uptake (P=0.004) and higher standardized uptake value (P=0.001).
Because positron emission tomography can neither differentiate pTis from T1 nor classify T, N, and M, it is not indicated in staging superficial esophageal cancer. Finding a synchronous primary tumor in approximately every 20th patient is its only benefit. Better, less expensive screening tools are available for common synchronous malignancies.
为确定氟脱氧葡萄糖正电子发射断层扫描是否适用于浅表癌的临床分期，我们试图判定其能否准确区分肿瘤（T）、区域淋巴结（N）及远处转移（M），包括区分高级别异型增生（Tis）与浸润性癌（T1）。
58例浅表食管癌患者术前行正电子发射断层扫描，其中53例（91%）与计算机断层扫描融合。将肿瘤特征、食管镜检查结果及pTNM与正电子发射断层扫描cTNM进行比较。pT1分为侵犯固有层或黏膜肌层的黏膜内癌以及侵犯内层或外层的黏膜下癌。
氟脱氧葡萄糖摄取随pT升高而增加，从pTis的5/11（45%）增至pT1（外层黏膜下）的11/16（69%），P = 0.07，标准化摄取值情况类似，pTis的中位数为0，pT1（外层黏膜下）为2.7，P = 0.06。正电子发射断层扫描无法区分Tis（5/11，45%）与T1（26/47，55%；P = 0.03）。3例患者区域淋巴结氟脱氧葡萄糖摄取呈假阳性（标准化摄取值为2.8、4.9、11）；6例pN1患者呈假阴性。正电子发射断层扫描对N1的敏感性及阳性预测值均为0%。无远处转移；1例患者术后15个月出现肺转移。正电子发射断层扫描检测到3个（5%）远处高代谢部位，均为同步肿瘤（甲状腺乳头状癌、肾上腺嗜铬细胞瘤、直肠腺瘤）。仅肿瘤长度增加与更高的氟脱氧葡萄糖摄取（P = 0.004）及更高的标准化摄取值（P = 0.001）相关。
由于正电子发射断层扫描既无法区分pTis与T1，也不能对T、N和M进行分期，因此不适用于浅表食管癌的分期。每20例患者中约有1例发现同步原发性肿瘤是其唯一益处。对于常见的同步恶性肿瘤，有更好、更便宜的筛查工具。
