[Evaluation of positron emission tomography by using F-18-fluorodeoxyglucose in diagnosis of recurrent colorectal cancer].

UNLABELLED

Accurate detection of recurrent colorectal carcinoma remains a clinical challenge. 18-F-fluorodeoxyglucose-positron emission tomography is new imaging technique that allows direct evaluation of cellular metabolism. This method is mainly used in oncology, especially in fusion with computer tomography (FDG-PET/CT, PET/CT Fusion). The aim of the study was to evaluate the usefulness of FDG-PET/CT in diagnosis of recurrent colorectal cancer.

MATERIAL AND METHODS

The results of FDG-PET/CT scan performed in 120 patients who had suspected recurrence disease were analyzed retrospectively. The definite diagnosis was established on the basis of histopathological examination or clinical follow-up. FDG-PET/CT results were compared with 76 computer tomography (CT), 30 magnetic resonance imaging (MRI), 81 ultrasonography (US), 75 chest roentgenogram (X-ray) and 91 carcinoembryonic antigen (CEA) test.

RESULTS

Recurrence colorectal cancer was demonstrated on FDG-PET-CT in 69 patients (57.5%). In 24 patients local recurrence, 33 liver metastases, 23 pulmonary metastases and in 36 other metastases were found. A total of 116 suspicious lesions were identified. The final diagnosis of recurrence was obtained in 56 patients (46.6%). Sensitivity, specificity, and accuracy for malignant findings were: for FDG-PET/CT 98, 94 and 97%; for CEA test 68, 82 and 72%; for CT scan 85, 91 and 89%; for RMI scan 96, 86 and 93%; for ultrasound test 71, 96 and 82%; for X-ray 87, 96 and 92%, respectively. FDG-PET-CT influenced surgical decisions in 23.6% of cases.

CONCLUSIONS

FDG-PET/CT is a very useful diagnostic method in case of patients with suspected recurrence of colorectal carcinoma. Its usefulness is higher than the serum level of CEA and other conventional imaging modalities (CT MRI, US, X-ray).