Clinical rotations are one or two calendar months long. In general, residents work one-on-one with an attending physician for one or two months at a time and they work with each attending physician approximately twice during the four-year residency. The American Board of Radiology requires Radiation Oncology residents to spend at least 36 months on clinical Radiation Oncology electives. Other rotations generally include one month of dosimetry/treatment planning and two months of diagnostic radiology, mini-fellowships and/or research time.