Magnetic resonance imaging (MRI) in rectal cancer: a comprehensive review

Magnetic resonance imaging (MRI) has established itself as the primary method for local staging in patients with rectal cancer. This is due to several factors, most importantly because of the ability to assess the status of circumferential resection margin. There are several newer developments being introduced continuously, such as diffusion-weighted imaging and imaging with 3 T. Assessment of loco-regional lymph nodes has also been investigated extensively using different approaches, but more work needs to be done. Finally, evaluation of tumours during or after preoperative treatment is becoming an everyday reality. All these new aspects prompt a review of the most recent advances and opinions. In this review, a comprehensive overview of the current status of MRI in the loco-regional assessment and management of rectal cancer is presented. The findings on MRI and their accuracy are reviewed based on the most up-to-date evidence. Optimisation of MRI acquisition and relevant regional anatomy are also presented, based on published literature and our own experience

Cross-sectional imaging for local staging of rectal cancer

Cross-sectional imaging plays a key role in the local staging of rectal cancer. The two main goals of imaging are to classify patients into differentiated tumour risk profiles for neoadjuvant treatment stratification and to provide an anatomical roadmap of the tumour for detailed planning of the surgical resection strategy. In many countries, MRI is considered the modality of the first choice for local staging of rectal cancer. Strengths of MRI include its ability to accurately stratify high-risk T3 and T4 tumours and to assess tumour invasion into important surgical landmarks including the mesorectal fascia and anal sphincter. CT should only be considered as an alternative for local staging in upper rectal tumours (close to the rectosigmoid junction) or in case of limited availability or contraindications for MRI. Restaging with imaging has recently gained clinical significance due to the shift in treatment towards organ-preserving treatments for patients that respond very well to neoadjuvant treatment. In this setting, use of anatomical MRI to detect and stage any residual tumour is limited by the presence of fibrosis, and the addition of functional imaging (diffusion-weighted MRI) helps to improve the performance of MRI

Early rectal cancer: the European Association for Endoscopic Surgery (EAES) clinical consensus conference

Background: The last 30 years have witnessed a significant increase in the diagnosis of early-stage rectal cancer and the development of new strategies to reduce the treatment-related morbidity. Currently, there is no consensus on the definition of early rectal cancer (ERC), and the best management of ERC has not been yet defined. The European Association for Endoscopic Surgery in collaboration with the European Society of Coloproctology developed this consensus conference to provide recommendations on ERC diagnosis, staging and treatment based on the available evidence. Methods: A multidisciplinary group of experts selected on their clinical and scientific expertise was invited to critically review the literature and to formulate evidence-based recommendations by the Delphi method. Recommendations were discussed at the plenary session of the 14th World Congress of Endoscopic Surgery, Paris, 26 June 2014, and then posted on the EAES website for open discussion. Results: Tumour biopsy has a low accuracy. Digital rectal examination plays a key role in the pre-operative work-up. Magnification chromoendoscopy, endoscopic ultrasound and magnetic resonance imaging are complementary staging modalities. Endoscopic submucosal dissection and transanal endoscopic microsurgery are the two established approaches for local excision (LE) of selected ERC. The role of all organ-sparing approaches including neoadjuvant therapies followed by LE should be formally assessed by randomized controlled trials. Rectal resection and total mesorectal excision is indicated in the presence of unfavourable features at the pathological evaluation of the LE specimen. The laparoscopic approach has better short-term outcomes and similar oncologic results when compared with open surgery. Conclusions: The management of ERC should always be based on a multidisciplinary approach, aiming to increase the rate of organ-preserving procedures without jeopardizing survival