Organ preservation in rectal cancer and improvements in the primary and response assessment

Total mesorectal excision (TME) remains the standard treatment for rectal cancer, achieving excellent oncological outcomes but with significant morbidity. Neoadjuvant radiotherapy and chemoradiotherapy have enabled organ-preserving approaches for patients with good or complete response, reducing the need for extensive surgery.

This thesis evaluated organ preservation, tumor reassessment, and lymph node staging. Local excision after neoadjuvant therapy proved safe in early-stage rectal cancer, with low recurrence and preserved quality of life, though bowel function may be affected. Multimodal assessment combining MRI and endoscopy improved detection of complete response.

USPIO-enhanced MRI and high-resolution ex-vivo MRI were investigated for lymph node evaluation, showing promise but requiring further research. Overall, the work supports organ-preserving strategies, accurate tumor assessment, and optimized MRI applications to guide personalized rectal cancer treatment.