Last verified on June 19, 2017The American Board of Radiology (ABR) offers the following alternate pathways to certification in radiation oncology: The International Medical Graduate (IMG) Alternate Pathway. An international medical graduate is defined as an individual trained in institutions outside the U.S., its territories, or Canada. The Holman Research Alternate Pathway The ABR recognizes the shortage of physician investigators in radiation oncology. To address this shortage, a research pathway program was designed for individuals to simultaneously train in radiation oncology and basic science, clinical, or transitional investigation. This pathway is named for B. Leonard Holman, MD, who first proposed this initiative.