Bibliometric Analysis of the Literature Regarding MRI-Linac: A Paradigm Shift in Radiation Oncology

Background: By integrating an MRI scanner and a linear accelerator, MR-linac systems provide superior soft tissue imaging and allow to perform adaptive radiotherapy adjusted on daily anatomical changes. The advent of this technology represents a revolution in radiation oncology and could improve treatment accuracy and clinical outcomes. We performed a comprehensive bibliometric analysis with the aim of displaying the available scientific literature and trends regarding MR-linac. Methods: Scopus database was investigated, considering documents published up to 6 April 2025. Keywords encompassed terms related to “MR-linac” or “MRI-linac” and possible combinations and acronyms. BibTeX data file was imported into Biblioshiny (Bibliometrix package—v. 4.1.4) and analysis was conducted using R code (R version 4.3.2) and the Bibliometrix package (version 4.1.4). Results: A total of 1624 articles on MR-linac were identified. The number of annual publications gradually increased from 21 in 2008, peaking at 211 in 2022 and then remaining substantially stable in subsequent years. Most of the papers were original articles (79.2%) and the majority was published by the 10 journals with the largest output. Remarkably, of 6385 identified authors, over 85% were from one of the 10 most represented countries (including European, North American and Asian nations). Consistently, the 10 institutions with the larger output were North American, Australian or European and provided over 60% of the articles. International co-authorship was found in only 23.6% of the articles. Keyword and co-occurrence analyses identified MR-guided radiotherapy, SBRT, dosimetry, and adaptive strategies as core themes, with emerging trends in radiomics, diffusion metrics, and deep learning. Conclusions: Bibliometric analysis identified trends and patterns of scientific publications regarding MR-linac, highlighting a growing interest in the topic. Nonetheless, it should be considered that the majority of the papers were published by a few journals and over 85% of authors were from 10 countries, demonstrating an evident disparity across nations. Multicentric international research protocols and common frameworks could foster the transition towards collaborative practice-changing studies.