Web of Science (WoS) is recognized as one of the most comprehensive, systematic, and authoritative databases, encompassing a vast array of literature metrics and over 12,000 high-quality journals from around the world. It is widely utilized for bibliometric analysis and visualization of scientific literature.

The literature screening process included in this study follows the PRISMA guidelines, as depicted in Figure 1 . Publications were retrieved from the Science Citation Index Expanded (SCI-Expanded) of WoSCC for the period spanning from January 1, 2014 to October 25, 2023. Data were downloaded on October 25, 2023, within a single day to mitigate biases arising from daily database updates. Search terms used were: ((((((((((((((((((((ALL=(Neoplasm, Stomach)) OR ALL=(Stomach Neoplasm)) OR ALL=(Neoplasms, Stomach)) OR ALL=(Gastric Neoplasms)) OR ALL=(Gastric Neoplasm)) OR ALL=(Neoplasm, Gastric)) OR ALL=(Neoplasms, Gastric)) OR ALL=(Cancer of Stomach)) OR ALL=(Stomach Cancers)) OR ALL=(Gastric Cancer)) OR ALL=(Cancer, Gastric)) OR ALL=(Cancers, Gastric)) OR ALL=(Gastric Cancers)) OR ALL=(Stomach Cancer)) OR ALL=(Cancer, Stomach)) OR ALL=(Cancers, Stomach)) OR ALL=(Cancer of the Stomach)) OR ALL=(Gastric Cancer, Familial Diffuse) AND (((((((((((((((((TS=(Radiotherapy)) OR ALL=(Radiotherapies)) OR ALL=(Radiation Therapy)) OR ALL=(Radiation Therapies)) OR ALL=(Therapies, Radiation)) OR ALL=(Radiation Treatment)) OR ALL=(Radiation Treatments)) OR ALL=(Treatment, Radiation)) OR ALL=(Radiotherapy, Targeted)) OR ALL=(Radiotherapies, Targeted)) OR ALL=(Targeted Radiotherapies)) OR ALL=(Targeted Radiotherapy)) OR ALL=(Targeted Radiation Therapy)) OR ALL=(Radiation Therapies, Targeted)) OR ALL=(Targeted Radiation Therapies)) OR ALL=(Therapies, Targeted Radiation)) OR ALL=(Therapy, Targeted Radiation)) OR ALL=(Radiation Therapy, Targeted).

Inclusion criteria encompassed: (1)English-language articles, reviews and meta-analyses pertaining to radiotherapy for gastric cancer; and (2) only published data were used.

Exclusion criteria included conference abstract, editorial material, book chapters, animal studies, and cadaver investigations.

Data collection: All relevant details were retrieved from the Web of Science in text format, encompassing author names, article categories, citation counts, countries, digital object identifiers (DOIs), impact factors, journal names, institutions, keywords, sample sizes, study designs, titles, and publication years.

Data analysis: Data were analyzed using R-studio for summarizing and visualizing scientific literature. R-studio provides a rich set of literature analysis packages and user-friendly syntax for efficiently processing large-scale literature data, extracting valuable insights, and uncovering developmental trends and key influencing factors in academic fields. The main steps are as follows: (1) importing the dataset into R software, (2) selecting the type of analysis (i.e., “co-occurrence network,” “thematic evolution,” and “main information”), and (3) setting analysis parameters.

From 2014 to 2023, a total of 484 articles were collected. Overall, these articles involved 2940 authors, averaging 8 authors per publication. There was a negative annual growth rate of -2.05%, resulting in a decrease in scientific output from 47 articles in 2014 to 39 articles in 2023 ( Figure 2 ). The average annual citations per article remained stable between 2 and 3 citations, with peaks in 2015 (2.46 citations per article) and 2019 (2.98 citations per article). The highest average citation per article was observed in 2015 at 24.63 citations, while the lowest was in 2023 at 0.54 citations, indicating a shorter duration of citable relevance.

In total, 186 journals published one or more of these articles. Table 1 and Figure 3 summarize the top 10 journals by publication volume and their basic information. Impact Factor (IF), often used to measure a journal’s importance within its field, represents the 5-year average number of citations. 17 journals (core sources) published approximately one-third of the retrieved documents. The most relevant journal was “FRONTIERS IN ONCOLOGY,” which published 17 articles from 2014 to 2023, followed by “BMC CANCER” (n = 13), “ANNALS OF SURGICAL ONCOLOGY” (n = 12), “CANCERS” (n = 12), and “RADIOTHERAPY AND ONCOLOGY” (n = 12). These journals predominantly fall within Q2, with impact factors around 5. Similar to most research fields, articles in the field of gastric cancer radiotherapy are mostly exploratory, with few achieving significant breakthroughs or providing high-level evidence in evidence-based medicine. Overall, the quality of articles in the field of gastric cancer radiotherapy remains good, with most articles located in the Q2 JCR zone.

Figure 4 illustrates the dynamics of the top 5 relevant journals. Among the top 5 journals, “FRONTIERS IN ONCOLOGY” and “CANCER” saw a rapid increase in published articles starting from 2018 and 2019 respectively, both originating from Switzerland. In contrast, the publication rate of the other three journals remained relatively stable. This highlights how “FRONTIERS IN ONCOLOGY” and “CANCER” have gathered excellent articles discussing gastric cancer radiotherapy in recent years.

( Table 2 , Figure 5 ) The most cited journals among all 484 articles (from the reference list) were “J CLIN ONCOL” with 1744 citations, followed by “INT J RADIAT ONCOL” with 1017 citations, “NEW ENGL J MED” with 779 citations, “LANCET ONCOL” with 548 citations, and “RADIOTHER ONCOL” with 464 citations. These journals are globally recognized top-tier publications that collect the highest quality articles on gastric cancer radiotherapy to date, many of which are considered landmark articles worthy of citation and reference by researchers worldwide. “J CLIN ONCOL” focuses on clinical oncology, while “INT J RADIAT ONCOL” specializes in radiation oncology, ranking first and second respectively among cited journals, underscoring their profound influence on the application of radiotherapy in gastric cancer.

The most prolific authors in terms of publications are Lee Jeeyun, Kang Won Ki, and Lim Do Hoon, with 11, 10, and 10 articles respectively. Among the top 10 authors by publication volume, they hail from South Korea, the Netherlands, and China. South Korea is the most productive in this field, primarily represented by Samsung Medical Center ( Table 3 ).

According to Lotka’s Law (7, 8)( Figure 6 ), the frequency distribution of scientific productivity identified 114 “core” authors who contributed to at least 3 articles (2.48%) and 2435 “occasional” authors who published only one paper (82.8%). Table 4 calculates the number of articles published by country based on the corresponding authors, with China topping the list. SCP (Single Country Publications) denotes articles where all authors are from the same country; MCP (Multiple Country Publications) indicates articles with authors from multiple countries, reflecting international collaboration. MCP Ratio = MCP/Articles denotes the proportion of collaborative articles in a country’s total publications. A higher value indicates more frequent international collaboration. According to MCP ratios, Turkey and major East Asian countries (China, Japan, South Korea) show relatively low rates of international collaboration, whereas North America (USA, Canada) and Europe (Netherlands, Germany, Italy) demonstrate higher rates. The national collaboration network based on publications shows the collaboration patterns between countries, with line thickness indicating the degree of collaboration closeness. Close collaborations are observed between the USA and Canada, USA and China, China and Singapore, and among European countries.

Table 5 and Figure 7 illustrate the production outputs by specific countries, with China leading with a total of 712 articles. In Figure 7 , darker colors indicate that the country has a higher publication volume. Significant affiliated institutions include China (Fudan University, Peking Union Medical College, Chinese Academy of Medical Sciences - Peking Union Medical College), South Korea (Samsung Medical Center, Sungkyunkwan University (SKKU)), followed by the USA (University of Texas System, UTMD Anderson Cancer Center, Harvard University), and the Netherlands (Netherlands Cancer Institute) ( Table 6 ).

The Table 7 lists the top 20 most cited articles in the field of gastric cancer (6, 9–27). Among these twenty papers, 13 are original articles, with 4 being clinical trials; 6 are systematic reviews/commentary articles, and 1 is a clinical practice guideline/consensus. The top-ranked article is “Treatment of gastric cancer,” cited globally 474 times. Most of these articles (n = 16) were published between 2014 and 2018, with limited recent publications (2019-2023), possibly due to a shorter citation window.

The Table 8 also lists the top 20 most cited articles in the field of gastric cancer radiotherapy (6, 10, 11, 14, 16, 25, 28–41).These articles better reflect the research advancements in radiotherapy for gastric cancer treatment.

Keywords are crystallizations of the content of an article, possessing high generality and reflective power within a particular research field, directly pointing to the essence of the text. Therefore, commonly used high-frequency keywords can present the focal issues of a research field, macroscopically reflecting the research hotspots within a certain period. To depict the current research status and hotspots in the field of gastric cancer radiotherapy, frequencies of keywords and the emergence of hot topics in different time periods were analyzed using R Studio ( Table 9 , Figure 8 ).

After searching for the terms “gastric cancer” and “radiotherapy,” analysis of the top 50 high-frequency keywords reveals that “surgery,” “adenocarcinoma,” “phase-III trial,” and “chemotherapy” are the most frequently appearing terms, with 140, 119, 118, and 100 occurrences respectively. This indicates that adenocarcinoma is the predominant pathological type of gastric cancer, with surgery and chemotherapy currently being the mainstream treatments. Radiotherapy continues to play a supportive role in gastric cancer treatment, as complete pathological remission is challenging to achieve solely with radiotherapy. Phase-III clinical trials remain the most evidence-based approach among all articles. The top 25 keywords mainly focus on gastric cancer treatments involving radiotherapy, chemotherapy, and surgery. Specific hotspots related to gastric cancer radiotherapy are reflected in keywords ranked 26-50, such as “neoadjuvant radiochemotherapy,” “gastroesophageal,” and “intensity-modulated radiotherapy.”

The main themes and trends are depicted in the Figure 9 . In the thematic map, the x-axis represents centrality, which indicates the importance of the field, while the y-axis represents density, which indicates the potential for development. Based on this, four quadrants can be drawn:•First quadrant (top-right corner): motor-themes, which are both important and well-developed. Second quadrant (top-left corner): very specialized/niche themes, which are well-developed but not important for the current field. Third quadrant (bottom-left corner): emerging or disappearing themes, which are marginal and underdeveloped, possibly newly emerging or about to disappear. Fourth quadrant (bottom-right corner): basic themes, which are important for the field but have not yet been well-developed. These generally refer to fundamental concepts.

The thematic map indicates emerging topics such as radiotherapy dose and treatment response, while clinical trials (survival, phase III trials) and treatment strategies (surgery, chemotherapy, radiotherapy, perioperative treatment) represent fundamental and cross-sectional themes. Checkpoint inhibitors and bleeding are isolated topics.

The national collaboration network ( Figure 10 ) shows country-based collaborations based on publications. The thickness of lines represents the proximity of collaboration. Close collaborations are observed between the United States and Canada, United States and China, China and Singapore, as well as Germany and Australia. There is a clear tendency for collaboration among European countries.

Analyzing national and institutional distributions allows us to identify major contributors in this field. China leads in publication quantity, benefiting from East Asia’s highest gastric cancer incidence and its large population of patients. Moreover, China’s numerous doctors and several top institutions involved in gastric cancer radiotherapy research contribute significantly to its high productivity. However, the institution with the most publications is Samsung Medical Center in South Korea, highlighting Korean institutions’ deep exploration in this medical domain. Two of the top five highly cited articles in gastric cancer radiotherapy originate from South Korea, demonstrating its significant influence in this field. Despite China’s relatively late start in this field compared to South Korea, its development pace has been remarkable, with both quantity and quality of publications steadily increasing in recent years. These achievements stem from comprehensive advancements in Chinese healthcare, although their impact still requires further enhancement.

The geographical distribution of scientific publications spans continents, reflecting gastric cancer’s high incidence globally. Primary scientific production centers are in Asia (China, South Korea), North America (United States, Canada), and Europe (Netherlands, Germany, Italy). South Korea and China exhibit high quantitative scientific output, showcasing concentrated rather than dispersed scientific capabilities. North American and European countries maintain high scientific productivity, often engaging in regional scientific collaborations. The geographic distribution of scientific outputs highlights top academic institutions in gastric cancer radiotherapy across different regions. One limitation of the current analysis is that collaboration is measured simplistically using shared authors, which may not fully capture active scientific networks or the scientific value of published works.

By analyzing journal sources, researchers can efficiently identify suitable outlets for their papers. Journals like “Frontiers in Oncology” and “Cancer” have shown the highest output in recent years, indicating significant influence in gastric cancer radiotherapy and suitability for submission. The impact factors of these journals partly reflect the importance and priority of radiotherapy. Such high-quality journals underscore the significance of radiotherapy in gastric cancer as a vital research direction.

Authors frequently cited are considered more influential than less cited ones. In terms of contributions and citations, the most influential authors in this field are Jeeyun Lee from South Korea and Annomieke Cats from the Netherlands, both leading large-scale Phase III clinical trials in adjuvant radiotherapy and chemoradiotherapy for gastric cancer. Their teams represent excellent potential collaborators for researchers in gastric cancer radiotherapy studies.

High-frequency keywords are pivotal in presenting hot topics within a research field, reflecting its evolving themes over different periods. From 2014 to 2016, gastric cancer radiotherapy primarily focused on “adjuvant therapy,” transitioning to “neoadjuvant chemoradiotherapy” from 2020 to 2022. Initially, studies emphasized radiotherapy forms (e.g., conformal radiotherapy) and dosages. Subsequently, due to the fixed location and high sensitivity of esophagogastric junction cancer, extensive research occurred from 2017 to 2019. In 2022, the advent of “nivolumab” marked the era of immunotherapy, resulting in a surge of articles on this topic. These developments illustrate discussions on treatment modalities, radiation patterns, treatment sites, and emerging combined therapies in gastric cancer radiotherapy.