Combined Treatment of Rectal Cancer Using Two-component Radiomodification with Neoadjuvant Radiation Therapy Together with a Chemotherapy
Authors:   N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia, Moscow, Russia, Barsukov Yu.A. , Tkachev S.I. ,   N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia, Moscow, Russia, Mammadli Z.Z. ,   N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia, Moscow, Russia, Aliev V.A. ,   N.N. Blokhin National Medical Research Center of Oncology, Ministry of Health of Russia, Moscow, Russia, Vlasov O.A. ,   Russian Scientific Center of Radiology and Nuclear Medicine, Ministry of Health of Russia, Moscow, Russia, Oltarzhevskaya N.D. ,   “Coletex” Ltd., Moscow, Russia, Korovina M.A. ,   “Coletex” Ltd., Moscow, Russia
Published: August 2022

Purpose: to evaluate the effectiveness of a “short” course of neoadjuvant radiation therapy using two radio modifiers with different mechanisms of radio-modulating action together with a drug therapy. Material and methods: To increase the effectiveness of radiation therapy there was created a variant of combined treatment of patients with rectal cancer, using the concept of polyradiomodification. Two radio modifiers have been applied (local microwave hyperthermia and intrarectal Metronidazole administration as part of a polymer composition) together with neoadjuvant radiation therapy and oral administration of Capecitabine, followed by surgical intervention 4–6 weeks after the end of radiation therapy. For intrarectal delivery of Metronidazole to the tumor, a new medical device was created, which is a biopolymer composition in the form of a hydrogel with a Metronidazole substance physically immobilized in it (RF Patent No. 2007139304, 2007). Results: The study included 520 patients, of whom 114 underwent a new variant of combined treatment with modulation of the effect of irradiation with two different radiomodifiers together with a drug therapy (group-1), 193 patients underwent only single-mode radiation therapy (group-2), and 213 patients underwent a combination of radiation therapy with local microwave hyperthermia (group-3). Toxic manifestations in group-1 was diagnosed in 38 (33,3 %) of 114 patients, general toxic manifestations of the III degree – in 13 (11,4 %) of 114. Postoperative complications in the group-1 was observed in 21 (18,4 %) of 114 patients, which was significantly less than in the group-2 and group-3, where they occurred in 78 (40,4 %) of 193 (p=0,0001) and in 78 (36,6 %) of 213 (p=0,0006). With a median follow-up of 54,6 months. relapses of cancer in the group-1 was not detected in any of 114 patients, which is significantly less than in the group-2, in which cancer relapses were diagnosed in 17 (8,8 %) of 193 patients (p=0,0011), and in the group-3, where they were detected in 10 (4,7 %) of 213 patients (p=0,0188). This made it possible to increase the number of sphincter-preserving operations performed in the group-1 to 84,2 %, which is significantly more compared to 53,4 % in the group-2 (p=0,00001) and 56,8 % in the group-3 (p=0,00001). It was also possible to significantly increase the rate of five-year relapse-free survival in the group-1 up to 82,9 % compared to 65,3 % at group-2 (p=0,01106) and 61,1 % at group-3 (p=0,00276). Conclusion: The treatment option using polyradiomodification is effective in improving local antitumor control of the disease and increasing relapse-free survival rates compared to other combined treatment options.