Treatment terminations during radiation therapy: A retrospective descriptive single-center analysis

Alaattin Ozen, Ilknur Harmankaya, Canan Ozdemır, Mehmet Halıcı, Oya Coskun, Ekin Baran Guler, Ozge Atılla, Sumeyra Can

Abstract:

Radiotherapy (RT) is a cornerstone of cancer management, substantially improving local tumor control and overall survival. However, a subset of patients fail to complete the prescribed RT course. Identifying the factors associated with treatment termination is essential to enhancing cancer care delivery and patient outcomes.

Introduction

Radiotherapy (RT) may be delivered with curative or palliative intent and can utilize conformal, intensity-modulated, or stereotactic techniques. It may be administered alone or alongside systemic cancer treatments. Approximately 50–60% of cancer patients require RT at some point in their disease course [1,2].

Materials and methods

The study was designed as a descriptive retrospective analysis and was not intended to evaluate causal relationships or independent predictors of treatment termination. This retrospective, single-center study included adult patients (≥18 years) who were scheduled to receive radiotherapy (RT) between 01/01/2020 and 12/31/2024.

Results:

Between 01/01/2020 and 12/31/2024, a total of 10,039 patients were scheduled for radiotherapy (RT) and underwent treatment planning. Among them, 297/10039 patients (2.96%) terminated RT after receiving at least one treatment fraction. A schematic patient flow is depicted in Fig 1.

Discussion

This study focused exclusively on patients who terminated radiotherapy after treatment initiation. Patients who failed to start RT following simulation were not included, as the determinants of non-initiation may differ substantially from those associated with treatment termination.

Conclusion

Radiotherapy termination occurred in a minority of patients, most commonly due to deterioration in performance status, and was more frequent among those receiving palliative-intent treatment. Despite higher termination rates, palliative patients completed a greater proportion of their prescribed fractions, likely reflecting the shorter hypofractionated schedules used in this setting.

Citation: Ozen A, Harmankaya I, Ozdemır C, Halıcı M, Coskun O, Guler EB, et al. (2026) Treatment terminations during radiation therapy: A retrospective descriptive single-center analysis. PLoS One 21(6): e0350496. https://doi.org/10.1371/journal.pone.0350496

Editor: Satyajeet Rath, All India Institute of Medical Sciences, INDIA

Received: January 5, 2026; Accepted: May 14, 2026; Published: June 4, 2026

Copyright: © 2026 Ozen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its figures.

Funding: The author(s) received no specific funding for this work.

Competing interests: The authors have declared that no competing interests exist. I have read the journal’s policy and the authors of this manuscript have the following competing interests: None.