Trends of mapping knowledge structure and themes of cancer sonodynamic therapy: a text-mining study

Sonodynamic therapy (SDT) is a non-invasive cancer treatment technique stemming from photodynamic therapy (PDT) and has garnered escalated interest among researchers in recent years. Numerous aspects of cancer SDT remain contentious, and the global research trajectory within this domain remains insufficiently explored. This study seeks to delineate the comprehensive knowledge framework, developmental trends, and pivotal research focal points concerning cancer SDT.

The study retrieved documents on cancer SDT from the Web of Science Core Collection (WoSCC) database spanning from 1 January 2000 to 7 December 2023. Bibliometric visualization was carried out through the utilization of CiteSpace 6.2 R6, VOSviewer 1.6.20, and an online analytical platform. Several bibliometric techniques including co-authorship, co-citation, co-occurrence, cluster, as well as burst analysis were used.

A total of 672 publications including 603 articles and 69 reviews were included. The annual publication count exhibited a steady increase over time, notably experiencing a surge, particularly in recent years. In terms of contributors, China has maintained its prominent position with the highest outputs and the most financial support. Chinese Academy of Sciences contributed the most articles. Materials Science was the most investigated research areas. Breast cancer emerged as the most extensively studied tumor, succeeded by sarcoma, hepatocellular carcinoma, melanoma, pancreatic cancer, glioma. According to co-cited references, "harnessing nanomaterial", "sonodynamic precision tumor therapy" and "metal-organic framework" denote the current and emerging research focuses within the field. In tandem with the results from keywords co-occurrence and burst, we identified the following research topics including mechanism of induced cell death (ferroptosis, immunogenic cell death), nano-related research (nanoplatform, nanozymes, nanomaterials, nanosheets, metal-organic frameworks (MOFs), nanocomposites, nanoparticles, nanosonosensitizers, liposomes, nanocarriers), combination therapies (chemodynamic therapy, immunotherapy, radiotherapy, photothermal therapy), and tumor microenvironment (hypoxia, singlet oxygen, oxidative stress), that may remain the research hotspots and receive sustained attention in the near future.

For the first time, this bibliometric analysis not only presents a comprehensive portrayal of the knowledge framework, but also delineates shifts in research focal points related to cancer SDT within the last two decades. This systematic summarization offers a comprehensive and lucid comprehension of cancer SDT, providing valuable insights for further investigations in this domain.