Surveying Retracted Studies and Notices Within the Field of Radiation Oncology

Purpose: The purpose of this study was to characterize retracted studies within the field of radiation oncology. Methods and Materials: Computerized searches were performed in Ovid MEDLINE, PubMed, Ovid EMBASE, and the Cochrane Library up to May 2017 looking for retracted studies using the terms “retraction note,” “retracted note,” “withdrawn” and “radiotherapy,” and “radiation oncology.” Additional studies were identified by hand-searching 10 discipline-specific journals. Two authors independently screened papers and then extracted author demographics, journal characteristics, and retraction-specific variables. Results: Of the 58 studies identified, the most common reasons for retraction were misconduct (43%), methodological error (21%), authorship issues (5%), unknown causes (5%), and journal (administrative) errors (3%). A total of 13 systematic reviews or protocols (22%) were withdrawn from the Cochrane Library for being out-of-date or redundant. All but one retracted study and retraction notice were available in portable document format. Of the 57 retrieved papers, 79% were identified as retracted via in-text notations or watermarks. Overall median time to retraction was 44 months (interquartile range, 11-98 months). However, 42 studies (72%) were still cited after retraction notices were published. Conclusions: A retracted study within the field of radiation oncology remains a relatively uncommon event. Although promising, our data suggest that the majority of these retracted articles continue to be cited as valid research. As such, there is still a need for clinicians to remain vigilant with their academic rigor and good clinical research practices. There is an urgent need for publication houses to foster universal publishing standards along with discipline-specific retraction guidelines.