Influence of interruptions in radiation therapy on long-term results of treatment of stage I-III head and neck cancers in the absence of surgical and chemoradiotherapy

Abstract

Despite the fact that head and neck tumors are very sensitive to radiation treatment, patients who have completed a course of radiation therapy have a high rate of recurrence and mortality from the underlying disease.The aim of the study was to analyze the event-free survival of patients who completed a course of radiation therapy for stage I-III head and neck cancer according to a radical program under the influence of a number of independent factors such as age, gender, total focal dose, disease stage, duration of a break in a split course of radiation therapy.The effect of the duration of interruption on survival was assessed by analyzing the treatment regimens for patients who received radiation treatment for stage I-III head and neck cancer according to a radical program from 2016 to 2018 at the Brest Regional Oncological Dispensary. Statistical processing of the obtained data included the analysis by the Cox regression method. Data were analyzed using the Kaplan-Meier method to evaluate the outcome.In the multivariate analysis, it was found that the disease stage has the greatest relationship with event-free survival (p < 0.01). The same trend is observed for the duration of interruption in radiotherapy (p < 0.05). The cumulative survival was significantly higher in the group of patients with treatment interruption of less than 3 weeks compared to the group of patients who completed treatment more than 3 weeks apart (80.00 % vs 49.06 %). If the duration of the break is less than 3 weeks, the clinical stage (T1-T3) is not a factor influencing patient survival.Accounting for the effect of interruptions in the course of radiotherapy and the understanding the influence of controllable factors is essential for optimal treatment strategies.