ĐẶC ĐIỂM HÌNH ẢNH CỘNG HƯỞNG TỪ TRONG ĐÁNH GIÁ GIAI ĐOẠN XÂM LẤN TẠI CHỖ VÀ DI CĂN HẠCH VÙNG TRÊN BỆNH NHÂN UNG THƯ TRỰC TRÀNG TẠI BỆNH VIỆN TRƯỜNG ĐẠI HỌC Y DƯỢC CẦN THƠ

Abstract

Background: In the multidisciplinary management of rectal cancer, pretreatment staging plays an important role in risk stratification and in planning an individualized treatment strategy for each patient. Objective: To investigate the magnetic resonance imaging characteristics in the assessment of local tumor invasion and regional lymph node metastasis in patients with rectal cancer. Materials and methods: A cross-sectional descriptive study was conducted on 44 patients with rectal cancer at Can Tho University of Medicine and Pharmacy Hospital. Results: Exophytic tumors accounted for 84.1% of cases, and all tumors were adenocarcinomas. Poorly differentiated tumors accounted for 63.6%. On histopathology, most cases were classified as T4 local invasion (56.8%) and N2 regional lymph node metastasis (56.8%). Tumors were most commonly located in the lower third of the rectum (43.2%) and were predominantly below the peritoneal reflection (52.3%). On magnetic resonance imaging, most tumors showed semicircumferential involvement (90.9%), intermediate signal intensity on T2-weighted imaging (84.1%), heterogeneous signal intensity (90.9%), and high signal intensity on diffusion-weighted imaging (90.9%). The mean tumor length was 52.89 ± 20.02 mm, and the mean tumor thickness was 16.38 ± 7.27 mm. Most cases were assessed as T4 local invasion (61.4%) and N2 regional lymph node metastasis (56.8%) on magnetic resonance imaging. Mesorectal fascia positivity was observed in 81.8% of patients. Conclusion: Magnetic resonance imaging is a valuable noninvasive imaging modality for rectal cancer staging. It enables assessment of the extent of local tumor invasion, regional lymph node metastasis, and mesorectal fascia involvement, thereby supporting pretreatment staging, risk stratification, and individualized treatment planning.