الفهرس | Only 14 pages are availabe for public view |
Abstract Colon cancer is very common type of cancer worldwide with the incidence and mortality rates vary markedly around the world. Colorectal cancer occurs in various anatomic locations in rectum with variable histological subtypes. Three major histological subtypes of colorectal cancer are identified: adenocarcinoma (AC), mucinous adenocarcinoma (MAC), and signet ring cell carcinoma (SRCC). Whereas typical ACs are the most common colorectal cancers and accounts for 96% of all CRCs. Most colorectal cancer patients are asymptomatic in the early stages and so colonoscopy and biopsy play a major role in diagnosis of colorectal cancer. Liver metastases occur in approximately half of the patients with colorectal cancer. The use of FDG PET-CT in the initial diagnosis of colorectal cancer is not justified while it has an important role in the evaluation of distant nodal (N), metastatic (M) staging and follow-up of colorectal cancer. PET/CT images allow both qualitative and quantitative analysis. Visual interpretation is susceptible to inter- and interobserver variabilities and defining thresholds to predict the outcomes on the basis of visual analysis only may not be possible. Quantitative analysis can overcome these limitations. SUVmax is the most commonly used 18F-FDG PET/CT parameter for diagnosis, staging and therapy monitoring. In our study we found that other quantitative PET parameters as MTV, TLG, percent MTV and TLG difference may provide additional diagnostic and prognostic value in patients with colorectal patients with liver metastases Limitations of the current Study: Retrospective nature of the study. Small number of patients. Incomplete data about interval therapy. Unequal interval between two scans. Suggestion for future researches: Increase number of patients or multicenter research. Measuring TLG for total lesions. Evaluating PET parameters in baseline PET/CT with long term follow up. |