Leveraging large language models for heuristic usability assessment of medical software: Insights with the Radiation Planning Assistant

While ChatGPT did not reveal any critical usability failures, its heuristic assessment proved valuable in prompting discussion, identifying minor refinements, and enriching both developer and user engagement with the RPA's interface design. This study demonstrates that LLMs can serve as an effective, low-cost complement to conventional heuristic evaluation, supporting early-stage usability review and stakeholder dialogue in the development of medical software.