PURPOSE

This study examined the sensitivity and specificity of CT/magnetic resonance imaging serial review compared to fluoro-2-deoxy glucose positron emission tomography-CT scanning to optimize colorectal cancer follow-up.

PATIENTS AND METHODS

Using standardized proformas, three blinded radiologists reviewed serial CT and magnetic resonance imaging in suspected cases of colorectal cancer recurrence in patients undergoing fluoro-2-deoxy glucose positron emission tomography-CT imaging.

RESULTS

Fifty eligible patients were included in the review. On follow-up, 23 patients had positive and 27 patients had negative diagnoses for colorectal cancer recurrence. Serial imaging review reduced the number of equivocal studies from 20 to 4 and unexplained carcinoembryonic antigen elevations from 17 to 10. Using fluoro-2-deoxy glucose positron emission tomography-CT, the number of equivocal studies reduced from 20 to 6 and unexplained carcinoembryonic antigen elevations reduced from 17 to 10. Fluoro-2-deoxy glucose positron emission tomography-CT altered management in 8 percent of patients (4/50, 95 percent CI, 0-16 percent). No significant differences were found between accuracy, sensitivity and specificity upon comparison of serial imaging review and fluoro-2-deoxy glucose positron emission tomography-CT in detecting recurrent disease. Extra information was demonstrated on 18 fluoro-2-deoxy glucose positron emission tomography-CT compared to serial imaging review in 8 of 50 patients and one patient had a positive incidental finding.

CONCLUSIONS

With suspected recurrence, we recommend undertaking serial imaging review with careful correlation of suspicious findings with previous studies. Fluoro-2-deoxy glucose positron emission tomography-CT imaging was useful when findings remain equivocal after serial imaging review for colorectal cancer recurrence.