Positron emission tomography for preoperative staging in patients with locally advanced or metastatic colorectal adenocarcinoma in lymph node metastasis.
OBJECTIVE
The impact of positron emission tomography was prospectively evaluated using 18 (F)-fluoro-deoxyglucose (FDG-PET) for the detection of lymph node (LN) metastasis in preoperative locally advanced colorectal adenocarcinoma, compared with computed tomography (CT) and pathologic findings.


METHODS
Fifty-three patients who were suspected of LN involvement by CT were staged preoperatively for LN metastasis using FDG-PET and CT. Regional LNs were classified into 3 groups, N1, N2-3, and N4, according to the Japanese General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus (6th Edition). A comparison of pathologic findings with CT and FDG-PET findings was used to calculate sensitivity, specificity, and accuracy.


RESULTS
The sensitivity, specificity and accuracy of CT/FDG-PET were 91.3%/52.2%, 91.7%/75.0% and 65.9%/72.3%, respectively, for N1, 91.7%/75.0%, 72.2%/94.4% and 77.1%/89.6%, respectively, for N2-3, and 100%/100%, 17.6%/100% and 41.7%/100%, respectively, for N4. The detection rate of the num ber of metastatic N1 LNs by CT was significantly higher than by FDG-PET, and not significantly in the N2-4 area. LNs hidden by strong halation of the primary tumor were not detected by FDG-PET.


CONCLUSIONS
While FDG-PET is markedly more sensitive than CT for detection of N4 LN involve. ment, the number of metastatic LNs is difficult to determine.
Kosugi
Chihiro
C
Division of Colorectal Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan. ckosugi0126@yahoo.co.jp
Saito
Norio
N
Murakami
Koji
K
Ochiai
Atsushi
A
Koda
Keiji
K
Ono
Masato
M
Sugito
Masanori
M
Ito
Masaaki
M
Oda
Kenji
K
Seike
Kazuhiro
K
Miyazaki
Masaru
M
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000556:secondary; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D011446:Prospective Studies