Background: Landmark research, e.g., randomized controlled clinical trials (RCTs), is often cited frequently. We correlated citations and journal impact factor of frequently cited RCTs published between 2000 and 2004. Material and Methods: The citation database Scopus was used to analyze number of citations. Results: Eighty-one publications were included, which achieved between 12 and 232 citations per year. A broad range of research questions were addressed, e.g., timing of radiotherapy, dose escalation, fractionation, and involved vs. extended field technique. Furthermore, radiotherapy alone was compared to combination treatment. Most RCTs were published in the Journal of Clinical Oncology (JCO), New England Journal of Medicine (NEJM), Lancet and International Journal of Radiation Oncology, Biology and Physics (IJROBP). These 4 journals were analyzed further. The journal with the highest impact factor (NEJM) had published RCTs that acquired significantly more citations than any other journal (median 74.5 per year). The Lancet ranked second, both regarding impact factor and citations (median 37 per year). The JCO (third highest impact factor) had published RCTs that acquired a median of 25 citations, which was not significantly different from that of the IJROBP, which had a much lower impact factor (median 23 citations per year). Ten out of the 11 most frequently cited RCTs were published in the NEJM or Lancet. Conclusions: Few of the most frequently cited publications appeared in journals with impact factor <20. Regarding the remaining studies, journal impact factor did not necessarily reflect citation figures.

Keywords: Radiation Oncology, Radiotherapy