Pre- And Postoperative Imaging Methods in Colorectal Cancer

Abstract

Introduction: Among the screening tests for colorectal cancer, colonoscopy is currently considered the most sensitive and specific technique. However, computed tomography colonography (CTC), magnetic resonance imaging (MRI), and transrectal ultrasonography have gained significant ground in the clinical practice of pre-treatment, screening and, more recently, post-treatment and surgical evaluation. Objective: To demonstrate the high accuracy of CT and MRI for pre and postoperative colorectal cancer staging. Methods: Search and analysis of articles in Pubmed, Scielo, Capes Periodicals and American College of Radiology with headings “colorectal cancer” and “colonography”. Weew selected 30 articles that contained radiological descriptions, management or statistical data related to this type of neoplasia. The criteria for radiological diagnosis were the American College of Radiology. Results : The great majority of patients with this subgroup of neoplasia is submitted to surgical procedures with the objective of cure or relief, except those with clinical contraindication. CTC colonography is not the most commonly used technique for screening; however, it is widely used for treatment planning, assessment of the abdomen for local complications or presence of metastasis, and post-surgical evaluation. MRI colonography is an alternative diagnostic method to CT, recommended by the American Society of Gastrointestinal Endoscopy. Although there are still no major studies on the use of MRI for screening, the high resolution examination has now shown good results for the American Joint Committee on Cancer TNM classification. Conclusion: MRI and CT represent the best means for colorectal neoplasm staging. The use of these methods as screening tools becomes beneficial to decrease complications and discomfort related to colonoscopy.

Magnetic Fields and Cancer: Epidemiology, Cellular Biology, and Theranostics

“…There is evidence that an important proportion of colorectal cancer patients remain untreated [541]. Pelvic MRI is used for the local of T and N staging of rectal cancer and has the advantage of improved patient comfort [542], improved reproducibility and accuracy [543], reduced care costs [544], and for completeness and better understanding of related pelvic anatomy [545][546][547]. The use of DWI with ADC value in addition to conventional MRI yields better diagnostic accuracy than using conventional MRI alone in detection, correlation with tumor histologic grade, and the initial staging in patients with locally advanced colorectal cancer [548,549]; however, DW-MRI is inferior to [F-18]-FDG-PET for the detection of primary lesions but superior for the detection of lymph node metastases [550].…”

Is There a Difference Between Right- Versus Left-Sided Colon Cancers? Does Side Make Any Difference in Long-Term Follow-Up?

“…Differences have been noted in the following characteristics: right-sided colon cancers are more likely to be exophytic, to be diploid, and to have mucinous histology and high microsatellite instability, whereas left-sided colon cancers are often infiltrating lesions, present with obstructive symptoms, and are more often aneuploid 5 , 15 , 23 , 35 .…”

Is Superficial Colorectal Lesions With Low and High Grades Intraepithelial Neoplasms More Prevalent in Older Above 65 Years?

“…Colorectal cancer is one of the most common cancers worldwide, and colonoscopy is the gold standard for detecting precancerous lesions at risk of progression to colorectal neoplasia 5 , 19 .…”