Collaborative Oncology: Preparing for a Multisite Trial to Facilitate Communication between Radiation Oncologists and Radiologists in Cancer Treatment Planning and Surveillance - Project Summary Radiotherapy (RT) planning systems are typically inaccessible to providers outside the RT department, making comprehensive sharing of RT targets a challenge. Many radiation oncologists (ROs) and radiologists feel that more collaboration is needed in both the pre-treatment planning and post treatment follow-up setting. Elimination of prevalent systemic barriers that currently limit collaboration between ROs and radiologists represents a low-cost, high-impact opportunity to improve cancer care delivery for the estimated 1 million US patients who receive RT each year. Improved communication could enhance RT target accuracy and reduce avoidable treatment toxicity, while also improving the efficiency and accuracy of post treatment imaging interpretation. Ultimately improved communication between providers has the potential to lead to improved locoregional cancer control, and beneficial impacts on patient stress and anxiety. Our multidisciplinary team of ROs, radiologists, and care delivery researchers developed the novel CORRECT workflow (Collaborative Oncology, between Radiologists and Radiation oncologists for the Evaluation of Contoured Targets) to enable efficient sharing of RT plans with diagnostic radiologists for input on accuracy of RT targets prior to treatment initiation. In our single site pilot trial, CORRECT facilitated communication between ROs and radiologists and led to substantial changes in treatment targets for 46% of reviewed lung cancer cases. Our pilot trial was promising but we need key information to inform a multi-site efficacy trial in collaboration with the Wake Forest NCI Community Oncology Research Program Research Base (WF NCORP RB). Specifically, we need to better understand: 1) feasibility of an updated workflow at community practices with varying usual patterns of RO-radiology collaboration for RT planning, 2) RO and radiology perspectives on barriers and facilitators to participation in the future trial, and 3) stakeholder preferences for key design features of the future trial. Community oncology practices may experience challenges in engaging radiology partners for research, thus it is critical to understand barriers and facilitators of provider engagement in future trials and ensure our promising feasibility and utility findings translate to community settings. To support the planning of a future Phase III multi-site efficacy trial of CORRECT to improve locoregional cancer control, we propose three Specific Aims. In Aim 1, we will determine feasibility and acceptability of CORRECT at 4 NCORP practices with varying RO-radiology collaboration for RT planning. In Aim 2, we will utilize semi structured interviews of ROs and radiologists to evaluate facilitators and barriers to RO-radiology research and clinical collaboration. Informants will include providers who participated in Aim 1 and providers who responded to our pre-grant survey indicating interest but with barriers to participation. For Aim 3, we will work closely with NCORP stakeholders to develop the future multicenter cluster randomized efficacy trial to determine the impact of CORRECT on locoregional cancer control outcomes, informed by data from Aims 1 and 2.