Large Language Model-Assisted Simplification of CT Staging Reports for Cancer Patients: A Prospective Quasi-Randomized Trial
Author Block: F. Busch, P. Prucker, K. K. Bressem, J. Peeken, A. W. Marka, S. H. Kim, S. Ziegelmayer, M. R. Makowski, L. C. Adams; Munich/DE
Purpose: To evaluate whether large language model (LLM)-assisted simplification of CT staging reports improves cancer patients' cognitive workload, text comprehension, report perception, and reading time.
Methods or Background: Prospective, controlled, open-label, quasi-randomized, pre-registered trial of 200 adult cancer patients undergoing routine CT re-staging with alternate 1:1 allocation to receive either the unmodified report or a locally generated LLM-simplified version (Llama-3.3-70B, on-premise via basebox) with mandatory radiologist review. Co-primary outcomes were reading time and three composite scores (cognitive workload, text comprehension, patient perception), each derived from three 7-point Likert items. Secondary outcomes included readability indices, word count, medical-terminology ratings, and independent radiologist assessments of factual errors, omissions, insertions, clinical usefulness, and overall quality. Logistic regression was performed to analyze patient-reported outcomes, adjusting for patient characteristics.
Results or Findings: Simplification reduced median reading time from 7 to 2 minutes (adjusted β: -3.86; 95% confidence interval (CI): -5.46, -2.26; P<.001). Patients reported lower cognitive workload (adjusted odds ratio (aOR): 0.18; 0.13, 0.25), higher text comprehension (aOR: 13.28; 9.31, 18.93), and enhanced perception of report usefulness (aOR: 5.46; 3.55, 8.38; all P<.001). Readability was significantly improved across metrics (e.g., Flesch-Kincaid Grade Level from 13.69 ± 1.13 to 8.89 ± 0.93; P<.001). Two radiologists independently identified factual errors in 6% of simplified reports (2 moderate, 4 severe), omissions in 7% (2 minor, 1 moderate, 4 severe), and unsupported insertions in 3% (1 minor, 2 moderate). The majority of simplified reports were rated clinically useful and of good or better quality.
Conclusion: LLM simplification substantially improves patient-centered outcomes and readability of CT staging reports while maintaining generally favorable clinical usefulness and quality. However, clinically relevant errors underscore the need for expert radiologist oversight before clinical implementation.
Limitations: Single-center, open-label with alternate allocation, self-reported patient outcomes.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Technical University of Munich (2025-186-S-KK)