Diagnostic value of (18)F-FDG PET/CT as first choice in the detection of recurrent colorectal cancer due to rising CEA.
BACKGROUND
The diagnostic value of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) as the first imaging approach in the evaluation of rising carcinoembryonic antigen (CEA) is not clear. The objective of this study was to investigate the value of (18)F-FDG PET/CT in patients with colorectal cancer (CRC) and suspected recurrence based on rising CEA.


METHODS
A total of 73 patients with CRC were referred to PET/CT after radical surgery. Generally, all patients were scheduled to follow a CT-based post-surgical follow-up regimen. In the case of rising CEA, (18)F-FDG PET/CT was performed in most patients with contrast-enhanced CT. The PET/CT images were independently reviewed by two readers. The presence or absence of recurrence was based on histology and/or standardized clinical follow-up.


RESULTS
Among 35 patients who had confirmed recurrence of CRC, PET/CT demonstrated recurrence with a sensitivity of 85.7 %, a specificity of 94.7 %, a positive predictive value of 93.8 %, and a negative predictive value of 87.8 %. The SUVmax ranged from 1.3 to 19.9. The mean time since the last postoperative imaging and PET/CT was 8 months (median 4 months). CEA values at referral ranged from 1.5 to 164.0 μg/L (median 5.6 μg/L). The diagnostic properties of PET/CT were analyzed in subgroups of patients with a single rising CEA sample (30 patients, 41 %), 31 patients (43 %) with two or more consecutive increases, and 12 patients (16 %) with persistently elevated values.


CONCLUSIONS
(18)F-FDG PET/contrast-enhanced CT has high diagnostic accuracy in the diagnosis of recurrent CRC, even in patients in a conventional CT-based follow-up program.
The Department of Nuclear Medicine, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, DK-9000, Aalborg, Denmark. michael.g@rn.dk.
Michael
M
Gade
The Department of Nuclear Medicine, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, DK-9000, Aalborg, Denmark. m.kubik9@yahoo.dk.
Magdalena
M
Kubik
The Department of Nuclear Medicine, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, DK-9000, Aalborg, Denmark. rvf@rn.dk.|The Department of Radiology, Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark. rvf@rn.dk.
Rune V
RV
Fisker
The Department of Gastrointestinal Surgery, Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark. otu@rn.dk.|The Department of Clinical Medicine, Aalborg University, Aalborg, Denmark. otu@rn.dk.
Ole
O
Thorlacius-Ussing
The Department of Nuclear Medicine, Clinical Cancer Research Center, Aalborg University Hospital, Hobrovej 18-22, DK-9000, Aalborg, Denmark. lajp@rn.dk.|The Department of Clinical Medicine, Aalborg University, Aalborg, Denmark. lajp@rn.dk.
Lars J
LJ
Petersen
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000601:surgery / Q000628:therapy; D003131:Combined Modality Therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000175:diagnosis* / Q000601:surgery / Q000628:therapy; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis / Q000601:surgery; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000601:surgery / Q000628:therapy; D012811:Sigmoid Neoplasms / Q000175:diagnosis / Q000601:surgery / Q000628:therapy; D014057:Tomography, X-Ray Computed
D002272:Carcinoembryonic Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18