ROLE OF PET/CT IN ASSESSMENT OF COLORECTAL CANCER

Abstract

Colorectal cancer is a leading cause of cancer worldwide and recurrence of colorectal cancer occurs in large proportion of patients within the first years after surgery. Resection of isolated metastases is associated with survival improvement while multifocal metastatic lesions are associated with less favorable prognosis. Early detection of recurrent colorectal carcinoma has become more important in the past decade, as the treatment options for localized disease have improved significantly; detection of tumor sites throughout the body is needed with high sensitivity and specificity. Preoperative chemoradiotherapy is increasingly used in patients with colorectal carcinoma and assessment of the therapeutic response is fundamental in order to change an ineffective but possibly toxic chemotherapy protocol or to decide surgical resection. Most radiologic procedures map the anatomy and morphology of tumors with little or no information about their metabolism. In recent years, imaging with positron emission tomography (PET) for tumor staging and therapy control has been introduced. Rather than anatomic information, it provides physiologic information on glucose uptake and metabolism. The main drawback of PET