[Role of radiotherapy in watch and wait strategy after neoadjuvant trerapy for rectal cancer].

For locally advanced (T3-4/N+M0) rectal cancer (LARC), radiation-based neoadjuvant therapy followed by total mesorectal excision (TME) is the standard treatment. For those who achieved clinical complete response (cCR), a non-operative management called "watch and wait" (W&W) strategery can preserve organ function and improve the life quality. For W&W strategy, radiotherapy is still the core part of neoadjuvant therapy. To increase the tumor response grade and cCR rate is the goal of optimized neoadjuvant regimens. In this review, we summarized the role of radiotherapy in the W&W strategy and discussed the advances of optimized radiation-based neoadjuvant therapy to achieve higher cCR rate, including new radiosensitizing agents, induction and consolidation chemotherapy, combination with immunotherapy, and prolonged interval time. All of the above efforts aim to improve patient survival and quality of life.