For the observational validation cohort (WP1), the major prerequisites have been achieved: regulatory approval for the registry and individual beneficiaries as well as the development of the eCRF and implementation of the database structure. Although these haven been slightly delayed and some deliverables needed to be postponed, these now lay the ground for a successful start in data collection for further analysis. The preparative part for standardisation of target delineation (WP2) has been completed. All benchmark documents containing recommendations for substrate definition, delineation and data transfer have been created. An interactive workshop has been held to transfer this knowledge to the different partners. The prospective registry (WP3) preparation is ongoing in all centres being Members of the Consortium but the advancement of the work varies considerably from one site to another. In most sites, the participation in the STOPSTORM registry has been accepted by local IRBs and these sites provided also national versions of patient information brochures and informed consent forms. The recruitment process to the prospective cohort has started and the first prospective patient data have been entered into the database. The enrolment rate is lower than planned (also due to covid19) but as subsequent national trials are initialized we expect the number of patients enrolled to the prospective cohort to grow faster. The collaboration among STOPSTORM partners will be crucial to develop and implement the research protocol on patient and healthcare professionals' experiences. In WP4 (Quality assurance of clinical structure delineation, treatment planning, and treatment delivery), we successfully performed STOPSTORM partner centre credentialing with dedicated audit and review workflows for STAR; comprehensive surveys on the STAR patterns-of-practise in Europe; multi-centre multi-platform benchmark studies for contouring and treatment planning; and treatment unit quality audits for STAR. Within those successful tasks and subtasks, we established treatment quality guidelines that are based on international recommendations for STAR and a credentialing and audit committee that will review all STAR cases using a dedicated central treatment review guideline with newly developed software for joined electrophysiology-radiotherapy data presentation. The Ethics and regulations WPs (WP6 and WP9) will continue working on both ethical and legal issues about the registry and prospective data collection. The dissemination framework for STOPSTORM (WP7) was established in the first eighteen months of the project. This included the website, logo, and social media platforms, along with both a data management and dissemination and exploitation plan. In addition, the consortium developed a 3-minute animation video to explain the project concept. The STOPSTORM partners were also active in dissemination and communication efforts, including press releases, project videos, presentations at virtual, global scientific conferences, and the publishing of peer-reviewed publications. The project management structure and consortium guidelines were established and distributed to the consortium via the PM Handbook (WP8) by Month 6. The project management strategy has thus far been sufficient to maintain lines of communication between partners and to ensure that any potential issues are addressed early and proactively.