As of March 2008 ASTRO counts almost 9,500 radiation oncologists, physicists, radiobiologists, oncology nurses, medical dosimetrists, physician assistants, program administrators, radiation therapists, veterinarians, radiation oncology residents, medical and clinical oncologists, and many other occupations among its members.
ASTRO Membership 2008
| Category | Number |
| Active | 4,214 |
| Affiliate | 65 |
| Allied | 138 |
| International | 1,121 |
| Associate | 1,210 |
| Associate/Nurse | 402 |
| Corresponding | 409 |
| Member-in-Training (current residents) | 626 |
| Member-in-Training (residency complete) | 51 |
| International Member-in-Training | 487 |
| Emeritus | 750 |
| Honorary | 23 |
| Total members as of July 1, 2007 | 9,496 |
For more information regarding the requirements, benefits and other information on the different ASTRO member categories please click on the appropriate link above.
Some other membership facts
- Outside of the United States ASTRO currently has members on every continent (except Antarctica) and in more than 80 different countries including Canada, Brazil, Chile, Nigeria, Ireland, Greece, Croatia and Japan to name just a few.
- By gender ASTRO members are approximately 75 percent male and 25 percent female.
- Approximately 60 percent of the members have their M.D., another 12 percent have a Ph.D., and 5 percent have both.
- Another 5 percent have nursing certifications including R.N., B.S.N., and/or O.C.N.
- ASTRO also counts a number of MBAs, lawyers and other professionals among its members.
All membership related numbers and other membership related information on this page are current as of March 2008.