Cáncer de recto: diagnóstico, estudio y estadificación

Rectal cancer: diagnosis, study and staging Rectal cancer is defi ned as a tumour located between the anal verge and 15 cm within anal verge. In rectal cancer, a precise preoperative staging allows to categorize patients for different available treatments, as well as decide the best surgical treatment. Preoperative staging is performed by several radiological tech- niques. Currently available procedures are endorectal ultrasound (EUS), computed tomography (CT) mag- netic resonance (MRI), positron emission tomography-computed tomography (PET/CT) and intraoperative ultrasound. EUS is a procedure performed by the colorrectal surgeon that allows the evaluation of the depth of tumour invasion as well as lymph node status; nevertheless its main shortcoming is the inability to assess mesorectal fascia involvement. Nowadays, MRI is the best method to assess mesorectal fascia involvement in addition to tumour invasion and lymph nodes involved. CT is a widely available procedure, and its main use is evaluation of distant metastases, with lower accuracy to assess tumour invasion and lymph node status. PET/CT is currently gaining importance, however its role in preoperative staging it's not widely accepted. IOUS allows evaluation of liver metastases during surgery, and therefore determines management and prog- nosis. Consequently, is necessary for surgeons to maintain an up-to-date knowledge of current methods, its advantages and limitations.