**1. Introduction**

Rectal cancer is currently a real public health problem, being the second most common type of cancer in women and the third most common type of cancer in men. Surgical treatment with curative intent (rectal resection with total mesorectal excision - TME) is the only therapeutic possibility that can ensure the healing of these patients [1].

In recent decades, the prognosis of these patients has significantly improved following the introduction in clinical practice of neoadjuvant radio chemotherapy, both to improve the life expectancy and to reduce the incidence of local recurrence. In this regard, studies show that in 15–27% of patients with rectal cancer, neoadjuvant radio-chemotherapy has caused a significant decrease in the size of tumors [2]. Therefore, a particularly important role in clinical practice is the

response identification to neoadjuvant therapy in these patients. At the same time, a particularly important role in the prognosis of patients, in addition to the response to neoadjuvant radio chemotherapy, is the surgery itself and especially the achievement of a total mesorectal excision (TME) as accurate as possible and obtaining negative surgical resection margins [3, 4].
