Performance of integrated FDG PET/contrast-enhanced CT in the diagnosis of recurrent colorectal cancer: Comparison with integrated FDG PET/non-contrast-enhanced CT and enhanced CT.
OBJECTIVE
The aim of our study was to evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) using (18)F-fluorodeoxyglucose (FDG) with IV contrast for depiction of suspected recurrent colorectal cancer and to assess the impact of PET/contrast-enhanced CT findings on clinical management compared with PET/non-contrast-enhanced CT and CT component.


METHODS
One hundred seventy patients previously treated for colorectal cancer underwent PET/CT consisting of non-enhanced and contrast-enhanced CT for suspected recurrence. PET/contrast-enhanced CT, PET/non-contrast-enhanced CT and enhanced CT were interpreted by two experienced radiologists by consensus for each investigation. Lesion status was determined on the basis of histopathology, radiological imaging and clinical follow-up for longer than 6 months.


RESULTS
Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/contrast-enhanced CT were 93.2 (69/74), 95.8 (92/96) and 94.7% (161/170), respectively, whereas those of PET/non-contrast-enhanced CT were 89.2 (66/74), 94.8 (91/96) and 92.4% (157/170), respectively, and those of enhanced CT were 79.7 (59/74), 93.8 (90/96) and 87.6% (149/170), respectively. Sensitivity and accuracy differed significantly among the three modalities (Cochran's Q test: p = 0.0004 and p = 0.0001, respectively).The findings of PET/contrast-enhanced CT resulted in a change of management for 64 of the 170 patients (38%) and had an effect on patient management in 12 patients (7%) diagnosed by enhanced CT alone and 4 patients (2%) diagnosed by PET/non-contrast-enhanced CT.


CONCLUSIONS
Integrated PET/contrast-enhanced CT is an accurate modality for assessing colorectal cancer recurrence and led to changes in the subsequent appropriate therapy.
Department of Radiology, Dokkyo University School of Medicine, Mibu, Japan. kazu10041976@yahoo.co.jp
Kazuhiro
K
Kitajima
Koji
K
Murakami
Erena
E
Yamasaki
Yasushi
Y
Domeki
Masahiro
M
Tsubaki
Masakatsu
M
Sunagawa
Yasushi
Y
Kaji
Narufumi
N
Suganuma
Kazuro
K
Sugimura
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18