The specific region of the body being treated with Radiotherapy.
National Codes
| P | Primary | 
| R | Regional Nodes | 
| 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 |