This study will evaluate whether an artificial intelligence chatbot can help patients better understand radiation therapy for localized prostate cancer. Participants will be adults with prostate cancer who are planning definitive radiation therapy at Brigham and Women's Hospital.

All participants will receive standard radiation therapy education and clinician-led discussions as part of routine care. In addition, participants will interact with an educational chatbot about prostate cancer radiation therapy. The chatbot is designed to provide plain-language information about treatment logistics, preparation, possible side effects, follow-up, and when to contact the care team. The chatbot will not provide diagnosis, treatment recommendations, individualized medical advice, or replace conversations with clinicians.

Participants will complete questionnaires before and after using the chatbot. The study will measure changes in patient understanding, confidence in managing symptoms, usability of the chatbot, and safety-related concerns identified during clinician review of chatbot responses.