EVALUATION OF THE EFFICA-CY OF CHRONOMEDULATED RADIOCHEMOTHERAPY IN PATIENTS WITH LOCALY AD-VANCED HEAD AND NECK CANCER

The article presents the results of administration of the chronomodulated radiochemotherapy method with 5-fluorouracil in the dose hypofractionation mode and methods for evaluating its effectiveness. This method is used in the SI “Grigoriev Institute for Medical Radiology of NAMS of Ukraine” in treatment of genital and rectal tumors, and was first tested in the treatment of locally advanced squamous cell carcinoma of the head and neck. The study included 74 patients with locally advanced squamous cell carcinoma of the head and neck (stages III, IVa, IVb). In the experimental group (39 patients), the treatment was performed in the chronomodulated dose hypofractionation mode with 5-fluorouracil chemomodification to 60-70 Gy of isoTFD (patent of Ukraine for utility model "Method of chemoradiation therapy of locally advanced laryngeal cancer" № 104194, Bull. № 1, 12.01.2016). In the comparison group (35 patients), independent remote radiotherapy was performed in the classical dose fractionation mode to the TFD of 60-70 Gy. The SCCA marker was detected in blood plasma by immunochemiluminescent analysis before and one month after the end of treatment. The efficacy of treatment was evaluated using the criteria of RECIST v.1.1, Kaplan-Meier Survival Curves and SCCA (squamous cell carcinoma antigen) marker dynamics with the help of the "STATISTICA 12" software package. Compared to independent radiation therapy, the developed method showed an increase in the frequency of objective tumor response to treatment from 57.2 to 77.0 % (p = 0.035) and two-year survival from 25.7 ± 7.4 to 46.2 ± 8,3 % (p = 0.034). The analysis of treatment toxicity revealed no statistically significant differences in both groups, which indicates the high tolerance of the developed method, and the possibility of its use in the treatment of patients with reduced somatic status and in elderly patients. The diagnostic sensitivity of the SCCA marker was 53.3 %. Statistically there was no difference between the mean scoring levels of SCCA in patients with stage III and IV, but the median in the group of patients with stage IV was by 1.5 times higher. Its dynamics correlates with an objective response to treatment (r = 0.68; p = 0.003). It should also be noted the relationship of absolute change in the level of SCCA tumor marker and time to death of patients (r = 0.5942; p = 0.015). It can play a prognostic role and influence the tactics of managing patients after the completion of chemo radiotherapy.