RESUMEN:
El cáncer colorrectal es el tercer cáncer más común y la segunda principal causa de muerte relacionada con el cáncer. El cáncer rectal representa aproximadamente un tercio de los nuevos casos de cáncer colorrectal, siendo el adenocarcinoma el subtipo predominante. A pesar de una disminución general en la incidencia y mortalidad, impulsada por avances en la prevención del cáncer, diagnóstico precoz y opciones de tratamiento mejoradas, hay un preocupante aumento en las tasas entre los pacientes jóvenes. Avances recientes significativos en el manejo del cáncer rectal localmente avanzado, como enfoques quirúrgicos, el uso de diferentes protocolos de tratamiento neoadyuvante para casos de alto riesgo y la adopción de estrategias de preservación de órganos, han aumentado el papel de los radiólogos en la evaluación locorregional a través de la resonancia magnética en la evaluación inicial, reestadificación y vigilancia activa de pacientes con cáncer rectal. Este manuscrito tiene como objetivo revisar el papel de la resonancia magnética rectal en la reestadificación después de la terapia neoadyuvante, proporcionando a los radiólogos una guía práctica para revisar exámenes en este contexto.

ABSTRACT:
Colorectal cancer is the third most common cancer and the second leading cause of cancer-related death. Rectal cancer accounts for approximately one-third of new colorectal cancer cases, with adenocarcinoma as the predominant subtype. Despite an overall decline in colorectal cancer incidence and mortality, due to advancements in screening, early diagnosis, and treatment options, there is a concerning increase in incidence rates among young patients. Recent significant advances in managing locally advanced rectal cancer, such as the establishment of different surgical approaches, neoadjuvant treatment using different protocols for highrisk cases, and the adoption of organ-preservation strategies, have increased the importance of the role played by radiologists in locoregional assessment on magnetic resonance imaging at baseline, at restaging, and during active surveillance of patients with rectal cancer. In this article, we review the role of restaging rectal magnetic resonance imaging after neoadjuvant therapy, providing radiologists with a practical, step-by-step guide for assessing treatment response.

ABSTRACT:
Colorectal cancer is the third most common cancer and the second leading cause of cancer-related death. Rectal cancer accounts for approximately one-third of new colorectal cancer cases, with adenocarcinoma as the predominant subtype. Despite an overall decline in colorectal cancer incidence and mortality, due to advancements in screening, early diagnosis, and treatment options, there is a concerning increase in incidence rates among young patients. Recent significant advances in managing locally advanced rectal cancer, such as the establishment of different surgical approaches, neoadjuvant treatment using different protocols for highrisk cases, and the adoption of organ-preservation strategies, have increased the importance of the role played by radiologists in locoregional assessment on magnetic resonance imaging at baseline, at restaging, and during active surveillance of patients with rectal cancer. In this article, we review the role of restaging rectal magnetic resonance imaging after neoadjuvant therapy, providing radiologists with a practical, step-by-step guide for assessing treatment response.