Table 2.

INRG staging system

INRG Stage	Definition
L1	Localised disease, without imaging defined risk factors (for example encasement of major blood vessels or encroachment into the spinal canal).
L2	Localised disease with imaging defined risk factors.
M	Metastatic disease which does not fall into the MS category (for example those aged less than 18 months with bone metastases, and all older patients with distant metastases).
MS	Age less than 18 months with metastatic disease limited to liver, skin or bone marrow.