Reasons for Declining Applicant Numbers in Radiation Oncology From the Applicants' Perspective: Results From the Applicant Concerns and Radiation Oncology Sources Survey (ACROSS).

Purpose: Applications to radiation oncology in the United States have decreased the past 3 years, resulting in unfilled residency positions (30 [14.5%] in 2019 and 35 [18.5%] in 2020).