PROJECT SUMMARY Many efficacious family-based interventions (FBIs) exist in cancer, but few have been integrated in routine care because they have not been designed/reported in a way that supports implementation. Barriers include resource- intensive designs that are incompatible with clinical workflows (e.g., multiple in-person visits or phone sessions with healthcare service providers) and a lack of healthcare reimbursement for services provided to caregivers. Making delivery channel adaptations could facilitate clinical uptake, and improve outcomes, but little guidance for adapting in-person/telephone-based FBIs for delivery via web/mobile platforms exists. This study uses Implementation Science (IS) and human-computer interaction principles to develop a model for adapting FBIs for digital delivery with the goal of improving uptake in oncology clinical care settings. We will adapt a highly promising telephone-based FBI called SHARE (Spouses coping with the Head and neck Radiation Experience) for delivery via mobile web (AIM 1), evaluate the feasibility, acceptability and non-inferiority of the new SHARE 2.0 prototype (AIM 2A), and elucidate factors that may influence implementation of SHARE 2.0 (AIM 2B). For AIM 1, we will adapt SHARE through collaborative efforts by assembling a stakeholder advisory committee (SAC) of 6 HNC patients and 6 caregivers to provide feedback on unadapted SHARE materials and desired technical features of SHARE 2.0 to inform an adaptation blueprint. Next, we will apply the Accelerated Creation-to- Sustainment (ACTS) model to iteratively develop SHARE 2.0 followed by usability testing with 5 patients and 5 caregivers. The outcome will be a functional prototype that is free from significant usability errors. For AIM 2A, we will conduct a single-arm trial of SHARE 2.0 with 65 patient-caregiver dyads. Participants complete surveys before initiating external beam radiation therapy (EBRT) and 1 month post-EBRT. We will judge the trial feasible and acceptable if results are consistent with at least 70% of eligible patients/caregivers enrolling and at least 80% reporting satisfaction with content/logistics. We will also examine whether SHARE 2.0 performs comparably to SHARE by comparing findings from this trial to the results of the original SHARE pilot trial. For AIM 2B, we will apply the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) QuEST (Qualitative Evaluation for Systematic Translation) mixed-methods framework to identify individual/organizational factors that may influence future adoption, implementation, and sustainability of SHARE 2.0 before proceeding to a hybrid implementation-effectiveness trial. Overall, this study will yield a functioning technology-enabled intervention that delivers symptom-management support, and meets the needs of stakeholders, thereby maximizing likelihood of uptake and sustainability in oncology clinical care. If successful, it could serve as a model for adapting other...