3307 - Premature Radiation Treatment Terminations in Gynecologic Cancer Patients: Assessment of 10 year Database Using a Novel Score at a Tertiary Care Center

Purpose/Objective(s): This retrospective study evaluated the utility of a recently developed Radiation Scoring tool in predicting premature radiation therapy (RT) termination in gynecologic cancer patients at a large tertiary center. Two cohorts were analyzed: one included patients (2013–2022) who prematurely terminated Radiation therapy (RT), and the other included those who completed RT (2024–2025) for comparison. This study aimed to assess the predictive utility of the gynecologic scoring tool.

Materials/Methods: Patients with gynecologic cancers who prematurely terminated RT between 2013 and 2022 were retrospectively reviewed. Collected data included age, ECOG performance status, treatment site, RT field, number of treatment fractions, use of systemic therapy, prior surgery, and comorbidities. Premature termination was defined as completing less than 100% of the prescribed RT course. Within the premature termination group, patients were further categorized as completing less than 90% versus 90% or more (but less than 100%) of prescribed treatment. A separate cohort of patients who completed their prescribed RT course between 2024 and 2025 was also analyzed. The Radiation Score (range 0-35) was calculated for all patients. Descriptive statistics were used to summarize patient characteristics. Univariable logistic regression was used to assess the association between the Radiation Score and premature RT termination. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the score's predictive accuracy. A significance level of 0.05 was used for all tests. Data analysis was performed using SAS version 9.4

Results: Of the 83 patients whose RT was prematurely terminated between 2013-2022, 76 (91%) completed less than 90% and 7 (9%) completed 90% or more of their prescribed treatment. In this cohort, the Radiation Score was not significantly associated with premature termination (p=0.955; odds ratio 1.01, 95% CI 0.81-1.25). A comparison between the 83 patients with premature RT termination (2013-2022) and 84 patients who completed RT (2020-2023) revealed a significantly higher mean Radiation Score in the premature termination group (20.1±3.6) compared to the completion group (17.8±8.0; p<0.0001). In this comparison, the Radiation Score was significantly associated with premature termination (p=0.0003). ECOG performance status (p<0.0001), disease site (p=0.03), and prior surgery (p=0.001) were also significantly associated with premature termination.

Conclusion: The score was significantly higher among patients who prematurely terminated RT compared to those who completed treatment in a separate cohort and this retrospective analysis of a 10-year premature RT termination database demonstrates that a RT predictive score is effective in identifying and managing RT treatment terminations in gynecologic oncology. A prospective validation or a larger set of patients can further validate the score for application into clinical practice.