Abstract: The efficacy of colorectal cancer treatment is not very satisfactory. Conventional morphologic imagings are limited in the diagnosis and in the applications of   multimodality treatment for colorectal cancer. ¹⁸F-fluorodeoxyglucose PET-CT can play a pivotal role in detecting metabolism changes and in the localization of lesions concurrently. It is valuable in the assessment of responses to therapy,  prediction of prognosis and  selecting modality management and monitoring postoperative recurrence. The rightmoment and proper application of PET-CT can increase the therapeutic efficacy of colorectal cancer. 

Key words: Colorectal carcinoma, Multimodality treatment, ¹⁸F-FDG PET-CT