Patterns and determinants of radiotherapy treatment default in a rural cancer centre: A retrospective observational study.

11175 Background: Radiotherapy requires uninterrupted daily treatment over several weeks, making treatment adherence challenging, particularly in rural and resource-limited settings. Treatment default adversely affects outcomes and reflects underlying socioeconomic, access-related and clinical barriers. There is limited real-world data from rural India evaluating the magnitude and determinants of treatment default. This study aimed to determine the radiotherapy default rate and identify the associated factors. Methods: This retrospective observational study included patients enrolled for definitive, adjuvant, and palliative radiotherapy over a 2 year period at a rural tertiary cancer centre. Radiotherapy default was defined as missing 3 or more consecutive fractions after initiation of treatment or failure to complete the planned prescribed dose. Descriptive statistics were used to summarise patient demographics, socioeconomic characteristics and clinical variables. The radiotherapy default rate was expressed as a percentage. Associations between radiotherapy default and categorical variables were analysed using Chi-square or Fisher’s exact test, as appropriate. Variables significant on univariate analysis were included in a multivariate logistic regression model to identify independent predictors of radiotherapy default. A p-value < 0.05 was considered statistically significant. Results: Among 2755 patients enrolled for radiotherapy during the study period, 363 patients defaulted, resulting in an overall default rate of ~13.2%. Higher default rates were significantly associated with longer daily travel distance, financial constraints, lower educational status, inadequate family support, poor baseline general condition, treatment related toxicities, diet-related difficulties- particularly among head and neck cancer patients (p < 0.05). On multivariate logistic regression analysis, long travel distance, financial constraints, poor general condition, inadequate family support and diet-related difficulties remained independent predictors of radiotherapy default. Conclusions: Radiotherapy default remains a clinically significant challenge in rural practice and is driven by a combination of socioeconomic, access-related and clinical factors. Long travel distance, financial constraints, inadequate family support, poor general condition and diet-related difficulties independently contribute to treatment default. Early identification of high-risk patients and targeted interventions—including patient and caregiver counselling, nutritional optimisation, financial and travel assistance, symptom control, and multidisciplinary supportive care—have the potential to reduce radiotherapy default rates and improve treatment completion in resource-limited settings.