The purpose of this study is to determine the feasibility of capturing daily dietary intake of patients undergoing radiation therapy using a mobile food record. This is a prospective single group, non-randomized, feasibility study.

20 participants will be identified during routine clinical care visits with the study PI or co-investigators. Consent will be obtained in person during a clinic visit or using the e-consent process described in section 21.1. They will be asked to use the myCircadian Clock (mCC) app to document their dietary intake for the duration of their radiation treatment. No follow up data will be collected.

Inclusion Criteria:

• Patients age ≥18 starting a new course of radiation therapy for cancer treatment
• Written informed consent obtained from participant and ability for participant to comply with the requirements of the study.
• Stated willingness to comply with all study procedures and availability for the duration of the study
• Own a smartphone or smart device
• Able to read and speak English

Exclusion Criteria:

• Pregnant or lactating women per self report prior to starting radiation therapy