The dissertation is devoted to improving the results of treatment of patients with locally advanced rectal cancer by studying the effectiveness of neoadjuvant radiation and chemoradiation therapy in the complex treatment of resectable locally advanced rectal cancer.
Work analysis of the results of treatment of 176 patients with locally spread rectal cancer (cT3c-4N1-2M0, with the presence of extramural vascular invasion (EMVI - extramural vascular invasion), with the involvement or destruction of the own fascia at the expense of the tumor itself or a metastatically affected lymph node (CRM+ - circumferential resection margin), who underwent a prolonged course of neoadjuvant chemotherapy, neoadjuvant radiation therapy and subsequent surgical intervention in the departments of radiotherapy, chemotherapy and tumor surgery of the Transcarpathian Antitumor Center from 2017 to 2022.
In all patients, the rectal tumor was morphologically verified. The degree of differentiation of tumor cells was determined taking into account the criteria of the international histological classification of tumors (WHO, 2010).
During the work, the patients were divided into 3 groups. The first two groups are a prospective, single-center, randomized, open study where a prolonged course of NRT or NCRT on a linear accelerator using VMAT and IMRT technologies was used in the treatment process (2021-2022). Group 3 included patients whose treatment results were studied retrospectively and who received treatment according to the NCRT standard without the use of 3D planning technologies, on a cobalt device (2017-2020).
The first (main) group included 57 patients with LARC who, as part of the neoadjuvant stage of treatment, received only a course of neoadjuvant PT in the fractionation mode (RVD 1.8 Gy/d, 5 fractions per week, SVD 50.4 Gy per regional lymph nodes of the pelvis and on the primary tumor and affected lymph nodes) in connection with the refusal of patients to perform chemotherapy at the non-adjuvant stage of treatment.
The second group (control group) included 56 patients with LARC who underwent a course of NCRT in the mode of classical fractionation (RVD 1.8 Gy/d, 5 fractions per week, SVD 50.4 Gy to the regional lymph nodes of the pelvis and to the primary tumor and affected lymph nodes) with capecitabine potentiation (825 mg/m2 2 r/d 5 days a week). In this group, patients gave their consent for NCRT with a radiopharmaceutical.
The third group (control group) consisted of 63 patients who received treatment according to the NCRT standard - the classical fractionation regime (RVD 1.8 Gy, SVD 50.4 Gy) in combination with capecitabine), but with the use of a cobalt device. The study was approved by the bioethical commission of the Uzhhorod National University. The study was conducted in accordance with the Helsinki Declaration of Human Rights. The average age of patients in our study was 56.7±2.06 years.
When comparing the MRI results performed before and after the end of the NCRT and NRT course in 160 (90.1%) of 176 patients, 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. When comparing the results of NCRT and NRT, a statistically significant difference was established in favor of NCRT, where in patients the distance between the distal border of the tumor and the anocutaneous line before treatment was 58.7 ± 1.48, and after NCRT this indicator was already 70.8 ± 1.28 ( p=0.0001), similarly, a similar picture is observed when using other methods, but when comparing NCRT and NRT, the best results were observed in the group where capecitabine augmentation was used, in contrast to the cobalt installation and the usual use of NRT in the mode of classical fractionation.
When comparing the results of radiation therapy according to the distance between the distal border of the tumor and the anocutaneous line, it was established that when using the VMAT technology, the results were the best in the II group of patients, where this indicator was 71.8±1.35 mm, compared to the I group and the III group, where the results were 64.4±2.10 mm and 63.5±3.29 mm, respectively (p=0.0001). When evaluating the extent of the tumor before and after neoadjuvant radiation therapy, a statistically significant difference was found in the comparison groups in favor of the VMAT technology in patients of the II group in comparison with the I and III groups (p=0.0001). When comparing the results of Group I and VMAT and IMRT technologies and Group III, it was found that that when using IMRT technology and classical fractionation without capecitabine enhancement and PT according to the same scheme with enhancement on a cobalt unit, no statistically significant difference was established. The obtained statistical results were checked using FDR and the Bonferroni test where p<0.001 indicators are relevant.
