Role of positron emission tomography/computed tomography for the staging of primary colorectal cancers

Abstract

ObjectiveThe aim of this paper was to evaluate the role of positron emission tomography (PET) combined with contrast-enhanced computed tomography (CECT) in staging patients with primary colorectal cancer (CRC).BackgroundCRC is the second leading cause of cancer-related deaths and the fourth most common malignancy worldwide. Cross-sectional imaging studies such as CT and MRI have evolved as the best modalities for staging rectal cancer. PET combined with CT is widely used not only for preoperative staging, but also for assessing the outcomes of rectal carcinoma.Patients and methodsThis prospective study was carried out on 50 patients: 30 (60%) men and 20 (40%) women in the age range from 27 to 74 years, who were diagnosed or suspected to have cancer colon by other radiological imaging.ResultsOur results showed that PET-CT had equal sensitivity (95.4%) and specificity (82%), positive predictive value (PPV) (80.7%), negative predictive value (NPV) (95.8%), and accuracy (88%) for the detection of regional lymph node metastasis compared to CECT. But PET-CT and CECT had higher sensitivity and higher specificity, PPV, NPV, and accuracy more than PET for detection of metastatic lymph nodes and PET-CT had equal sensitivity (92.8%) and specificity (86.2%), PPV (72.2%), NPV (96.8%), and accuracy (88%) for detection of lung metastasis compared to PET. But PET-CT and PET had higher sensitivity and higher specificity, PPV, NPV, and accuracy more than CECT for detection of pulmonary deposits.ConclusionAccording to our results, fluorine-18 fluorodeoxyglucose PET/CT has contributed positively to the staging of primary CRC patients.