New opportunities of drug delivery in oncology

Abstract

Objective. Development of methods for accompanying therapy to protect normal organs and tissues in the irradiation zone. Method. The study included 112 patients with cervical and endometrial cancer after combined or independent radiotherapy from 2012 to 2016. In 71 female patients of the main group, Derinat with hydrogel was applied as a supportive therapy and in 41 patients of the control group, conventional prevention methods (olive oil, sunflower oil, methyluracyl ointment) were applied. For prevention of vaginal mucosal and cervical epitheliitis in the main group, hydrogel was used as applications from the first radiation day. For prevention of radiation proctitis, hydrogel was injected into the rectum once daily from the first radiation day. Hydrogel instillations into the bladder were started only with the first clinical signs of cystitis. For prevention of radiation reactions, vaginal oil and ointment and rectal oil micro-enema were administered to patients of the control group from the first day of irradiation. Radiation cystitis was treated with vegetable diuretics and uroseptic drugs. Results. Using the hydrogel with Derinat allowed to administer a course of radiotherapy without interruption in 84.5% (60/71) of patients and only in 48.8% (20/41) in the control group. Radiation cystitis occurred 60% less frequently (25.3% ± 3.3 versus 63.4% ± 2.7, p <0.01). Analysis of radiation cystitis severity in two groups (according to RTOG) showed that 75% of patients in the main group had grade I and 25% had grade II. Grade III and grade IV did not occur. At the same time, in the control group, grade I radiation cystitis developed in 44% of patients, grade II — in 40%, and grade III — in 16% of patients. The hydrogel treatment halved the frequency of radiation proctitis (26.7% ± 3.3 vs. 53.7% ± 3.2 p <0.1). With daily application of the hydrogel with Derinat, grade I epitheliitis (53.5%) predominated in vaginal and cervical mucosa, grade II was observed in 29.5%, and grade III radiation reaction — only in 16.9% of cases; grade IV reaction was not observed. In the control group, these proportions were 26.8%, 24.3%, 31.7%, and 17.2%, respectively. Cytological criteria were developed to evaluate the course of radiation reactions in the vaginal mucosa. Three degrees of change in the cytogram were identified, which correlated with clinical picture. In the main group, incidence of grade I radiation-induced changes was increased by more than 350% (52 ± 9.9% vs. 11.5 ± 6.3%, p <0.002), and incidence of grade III was decreased by more than 70% compared to the control group (12 ± 6.5% vs. 46.1 ± 9.8%, p <0.003). Conclusion. Using the hydrogel material with Derinat as an accompanying therapy during the course of irradiation allows to reduce frequency and severity of radiation injuries of the vaginal mucosa, bladder, and rectum, administer an uninterrupted course of radiotherapy, and improve the quality of life of patients.