Topometric Preparation and Planning of Neoadjuvant Radiotherapy in the Complex Treatment of Rectal Cancer

Abstract

Objective(s). To evaluate the effectiveness of the use of topometry during neoadjuvant radiation therapy in the complex treatment of rectal cancer.
 Methods. The results of treatment of 113 patients with locally advanced rectal cancer (cT3c-4N1-2M0) were analyzed. The patients were divided into two groups: the first (main) group included 57 patients who received only a course of neoadjuvant radiation therapy as part of the neoadjuvant stage of treatment. The second group (control group) included 56 patients who underwent a course of radiation therapy with capecitabine potentiation. Topometric preparation, contouring of irradiated volumes, critical structures and radiation treatment of all patients included in the study were carried out according to standard principles and started 5 days before its implementation.
 Results. When comparing the results of MRI performed before the beginning and after the end of the radiation therapy course in 102 (90.2%) of 113, a positive trend was noted in the form of a decrease in the length of the tumor itself and an increase in the distance between the tumor and the anal edge, p=0.0001. No statistically significant differences were found when evaluating the influence of criteria of intragroup effects on the reduction of tumor length when choosing fractionation modes.
 Conclusions. In 52 (91.2%) patients of the main group and 51 (911%) of the control group had a positive CRM status. Analysis of CRM status in patients before and after the end of the course of neoadjuvant radiation therapy showed positive dynamics, both in the main and in the control group (p<0.000). After a prolonged course of neoadjuvant radiation therapy, the number of patients with a positive CRM status decreased to 17 (30%) in the main group and 19 (34%) in the control group (p<0.000). According to the MRI results performed before and after the course of neoadjuvant radiation therapy in 102 (90.2%) out of 113, positive dynamics were noted in the form of a decrease in the length of the tumor itself and an increase in the distance between the tumor and the anal edge, p=0, 0001.