Calculators & Tools

Medulloblastoma / CNS Embryonal — Chang M-Stage

Metastatic staging of medulloblastoma and other CNS embryonal tumours.

1 What is the Medulloblastoma / CNS Embryonal — Chang M-Stage?

The Medulloblastoma / CNS Embryonal — Chang M-Stage is a oncology scoring tool used in paediatric practice. Metastatic staging of medulloblastoma and other CNS embryonal tumours. It scores 1 criteria and interprets the total across 4 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.

2 When to use it

  • Grading severity at the bedside in oncology
  • Recording an objective severity band in the case notes
  • Deciding when a total crosses the threshold for escalation
  • Re-scoring to track whether a child is improving or deteriorating
  • Checking the exact criteria of a score used infrequently

3 Formula & method

The score sums 1 criteria: Metastatic status. Totals are then banded: 1 stage or more - M0 - standard risk (if resected): m0 with <1.5 cm² residual tumour and age ≥3 years = standard risk. Craniospinal radiotherapy plus chemotherapy; 2 stage or more - M1 - high risk: m1 - positive CSF cytology places the patient in the high-risk group; 3 stage or more - M2-M3 - high risk: gross nodular seeding (intracranial or spinal) - high-risk disease requiring intensified therapy; 5 stage or more - M4 - high risk, extraneural: m4 - extraneural metastasis; rare and carries the poorest prognosis.
  • Risk stratification also uses extent of resection (residual <1.5 cm²), age (<3 years) and molecular subgroup (WNT, SHH, Group 3, Group 4).
  • Source: Chang CH, Housepian EM, Herbert C. An operative staging system and a megavoltage radiotherapeutic technique for cerebellar medulloblastomas. Radiology 1969;93:1351-9.
  • Source: Gupta S, Aitken JF, Bartels U et al. Paediatric cancer stage in population-based cancer registries: the Toronto consensus principles and guidelines. Lancet Oncol 2016;17:e163-72.

4 Frequently asked questions

How many criteria does the Medulloblastoma / CNS Embryonal — Chang M-Stage use?

1. They are Metastatic status.

What do the bands of the Medulloblastoma / CNS Embryonal — Chang M-Stage mean?

The total is interpreted as: 1 stage or more - M0 - standard risk (if resected): m0 with <1.5 cm² residual tumour and age ≥3 years = standard risk. Craniospinal radiotherapy plus chemotherapy; 2 stage or more - M1 - high risk: m1 - positive CSF cytology places the patient in the high-risk group; 3 stage or more - M2-M3 - high risk: gross nodular seeding (intracranial or spinal) - high-risk disease requiring intensified therapy; 5 stage or more - M4 - high risk, extraneural: m4 - extraneural metastasis; rare and carries the poorest prognosis.

Does the score replace clinical judgement?

No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.

Where does this score come from?

Risk stratification also uses extent of resection (residual <1.5 cm²), age (<3 years) and molecular subgroup (WNT, SHH, Group 3, Group 4).

Does it work offline?

Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.