The area or region to be treated with Radiotherapy.
National Codes
| P | Primary |
| PR | Primary and Regional Nodes |
| A | Non-anatomically specific primary site |
| O | Prophylactic (to non-primary site) |
| M | Metastasis |
This attribute is also known by these names:
| Context | Alias |
|---|---|
| plural | RADIOTHERAPY TREATMENT REGIONS |

