ABSTRACT Community-led Action Research in Oncology ? Pandemic-appropriate Radiotherapy Innovations Evaluated for LMICs (CLARO PARTE for LMICs) This application is being submitted in response to the Notice of Special Interest (NOSI) identified as NOT-CA- 21-033. This participatory action research (PAR) study will assess radiotherapy (RT) innovations in partnership with oncology professionals in Latin America and the Caribbean (LAC). We will leverage global experience and relationships of the Community-led Action Research in Oncology (CLARO) global oncology research team at Norris Cotton Cancer Center (NCCC) and involve RT professionals throughout LAC in evaluating ?frugal innovations,? which were developed during the COVID-19 pandemic and are defined as the creation of unexpected solution that are simpler and disruptive alternatives to provide adequate healthcare within reach of everyone (Tran et al. 2016). Our overall goal is to identify frugal innovations and evaluate them for safety, efficiency, quality, feasibility, acceptability, and potential potency, to assess adaptability for use in future pandemics, or other public health emergencies. Phase 1 involves convening LAC RT professionals in a Project ECHOTM (Extension for Community Healthcare Outcomes) tele-mentoring partnership to share frugal innovations devised by their clinics during the COVID-19 pandemic. The Latin-American and Caribbean Society for Medical Oncology (SLACOM) will facilitate a panel of RT professionals joining the teleconferences. In Phase 2, physicians and scientists experienced in radiation oncology and innovation will evaluate innovations for effects on virus control, maintenance of clinical operations, and continuance of quality care by a multidisciplinary team applying international standards. The innovations that meet standards will advance to Phase 3, returning to the panel of LAC RT professionals where participants will engage in a Delphi consensus- building process to assess feasibility, acceptability within their setting, and potential potency. Relying on highly participatory and iterative processes, which are the hallmarks of Participatory Action Research (PAR), we will move from data collection and reflection to action and improvement, leveraging relationships between NCCC?s CLARO and SLACOM. Ultimately, we will develop a manual of scalable frugal RT innovations suitable for LMICs in a pandemic. Innovations will be organized topically: routing, hygiene, ventilation, PPE, and scheduling, etc. and further organized in matrixes by high/low impact and high/low cost.