Background: The therapeutic potential of proton therapy (PT) was first recognized in 1946 by Robert Wilson, and nowadays, over 100 proton centers are in operation worldwide, and more than 60 are under construction or planned. Bibliometric data can be used to perform a structured analysis of large amounts of scientific data to provide new insights, e.g., to assess the growth and development of the field and to identify research trends and hot topics. The aim of this study is to provide a comprehensive bibliometric analysis of the current status and trends in scientific literature in the PT field. Methods: The literature on PT until the 31st December 2022 in the Scopus database was searched, including the following keywords:protonANDradiotherapyANDcancer/tumorin title, abstract, and/or keywords. The open-source R Studio’s Bibliometrix package and Biblioshiny software (version 2.0) were used to perform the analysis. Results: A total of 7335 documents, mainly articles (n = 4794, 65%) and reviews (n = 1527, 21%), were collected from 1946 to 2022 from 1054 sources and 21,696 authors. Of these, roughly 84% (n = 6167) were produced in the last 15 years (2008–2022), in which the mean annual growth rate was 13%. Considering the corresponding author’s country, 79 countries contributed to the literature; the USA was the top contributor, with 2765 (38%) documents, of whom 84% were single-country publications (SCP), followed by Germany and Japan, with 535 and 531 documents of whom 66% and 93% were SCP. Considering the themes subanalysis (2002–2022), a total of 7192 documents were analyzed; among all keywords used by authors, the top three were radiotherapy (n = 1394, 21% of documents), intensity-modulated radiotherapy (n = 301, 5%), and prostate cancer (n = 301, 5%). Among disease types, prostate cancer is followed by chordoma, head and neck, and breast cancer. The change in trend themes demonstrated the fast evolution of hotspots in PT; among the most recent trends, the appearance of flash, radiomics,relative biological effectiveness (RBE), andlinear energy transfer (LET)deserve to be highlighted. Conclusions: The results of the present bibliometric analysis showed that PT is an active and rapidly increasing field of research. Themes of the published works encompass the main aspects of its application in clinical practice, such as the comparison with the actual photon-based standard of care technique and the continuing technological advances. This analysis gives an overview of past scientific production and, most importantly, provides a useful point of view on the future directions of the research activities.
背景：质子治疗（PT）的治疗潜力最早由罗伯特·威尔逊于1946年提出，如今全球已有超过100个质子中心在运行，另有60多个正在建设或规划中。文献计量数据可用于对大量科学数据进行结构化分析，从而提供新的见解，例如评估该领域的增长与发展，并识别研究趋势和热点。本研究旨在对PT领域的科学文献现状和趋势进行全面文献计量分析。方法：检索Scopus数据库中截至2022年12月31日关于PT的文献，检索词包括标题、摘要和/或关键词中的"质子"、"放射治疗"和"癌症/肿瘤"。使用开源R Studio的Bibliometrix软件包和Biblioshiny软件（2.0版）进行分析。结果：共收集到1946年至2022年间的7335篇文献，主要类型为文章（n=4794，65%）和综述（n=1527，21%），来自1054个来源和21,696位作者。其中约84%（n=6167）产生于最近15年（2008-2022年），年均增长率为13%。从通讯作者所属国家来看，共有79个国家贡献了文献；美国是最大贡献者，共发表2765篇（38%），其中84%为单国出版物（SCP），其次是德国和日本，分别发表535篇和531篇，其中SCP占比分别为66%和93%。在主题子分析（2002-2022年）中，共分析了7192篇文献；在作者使用的所有关键词中，排名前三的是放射治疗（n=1394，占文献的21%）、调强放射治疗（n=301，5%）和前列腺癌（n=301，5%）。在疾病类型中，前列腺癌之后依次是脊索瘤、头颈癌和乳腺癌。趋势主题的变化表明PT领域热点快速演变；在最新趋势中，FLASH、放射组学、相对生物有效性（RBE）和线性能量转移（LET）的出现值得关注。结论：本次文献计量分析结果表明，PT是一个活跃且快速发展的研究领域。已发表作品的主题涵盖了其在临床应用中的主要方面，例如与当前基于光子的标准治疗技术的比较以及持续的技术进步。该分析概述了过去的科研成果，更重要的是为未来研究方向提供了有益视角。
More than Five Decades of Proton Therapy: A Bibliometric Overview of the Scientific Literature
肿瘤(癌症)患者之家