The problems this contract is addressing include making it easy for patients to report toxicities after radiation therapy so that they can be timely and accurate and so that they can be incorporated into a medical database for use by medical professionals. This would allow the app to recommend (when appropriate), and for clinicians to intervene, with appropriate treatments and will lead to better design of patient-centric clinical trials. There is a need for a patient-facing smartphone mobile app that will ultimately improve treatment outcomes. The Phase-I scope includes developing Mobile PRO-CTCAE Administration System (mPROS), a smartphone application, that is tailorable, engaging, and relevant, and enables collection of high-quality symptom data related to radiation toxicities. The outcomes of this contract will include categorizing relevant PRO-CTCAE items for cancer patients treated with radiation therapy in the head/neck, breast, and pelvic anatomical areas, and structuring them in such a way that mPROS will be capable of administering tailored and personalized PRO-CTCAE items in an engaging and patient-centric manner.