CNS-IPI Risk Calculator
Use this tool to estimate Central Nervous System International Prognostic Index (CNS-IPI) risk category in diffuse large B-cell lymphoma (DLBCL).
What is the CNS-IPI?
The CNS-IPI is a clinical scoring system used to estimate the risk of central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL). It builds on the traditional IPI (International Prognostic Index) and adds one extra high-risk feature: kidney or adrenal involvement.
This type of risk stratification helps teams discuss whether additional CNS-directed staging and prophylaxis should be considered. It does not replace pathology review, imaging, molecular profiling, or physician judgment.
How the calculator works
The score includes six binary factors. Each present factor contributes 1 point:
- Age > 60 years
- ECOG performance status > 1
- Elevated serum LDH
- Stage III or IV disease
- More than one extranodal site
- Kidney and/or adrenal involvement
Total score range: 0 to 6.
CNS-IPI risk groups
| Score | Risk Group | Typical 2-year CNS Relapse Risk* |
|---|---|---|
| 0-1 | Low | ~0.6% |
| 2-3 | Intermediate | ~3.4% |
| 4-6 | High | ~10.2% |
*Rates are approximate and depend on cohort, treatment era, and disease biology.
Why clinicians use a CNS IPI calculator
A quick CNS IPI calculation can support:
- Structured risk discussion at diagnosis
- Selection of patients for deeper CNS workup
- Shared decision-making around prophylaxis strategies
- Documentation consistency across multidisciplinary teams
Important limitations
No scoring model can capture every biologic risk signal. CNS relapse risk is also influenced by molecular and site-specific factors not included in the base CNS-IPI score. Real-world decisions often integrate:
- Cell of origin and molecular subtype
- Double-hit/triple-hit features
- Specific extranodal sites beyond kidney/adrenal
- Patient comorbidity and treatment tolerance
- Institutional protocols and current evidence updates
Practical interpretation tips
Low risk (0-1)
Generally associated with very low CNS relapse probability. Standard systemic management is usually the main focus.
Intermediate risk (2-3)
Represents a gray zone where individualized assessment is crucial. Additional risk markers may shift management discussions.
High risk (4-6)
Signals materially higher relapse risk. Teams may evaluate CNS-directed strategies more actively depending on full clinical context.
Frequently asked questions
Is CNS-IPI the same as IPI?
No. CNS-IPI includes all core IPI components and adds kidney/adrenal involvement as a sixth CNS-specific factor.
Can this tool diagnose CNS disease?
No. It is a risk estimator only, not a diagnostic test.
Should treatment decisions rely on this score alone?
They should not. Use CNS-IPI alongside clinician expertise, pathology, imaging, and current treatment guidelines.
Medical note: This page is educational and not a substitute for professional medical advice, diagnosis, or treatment.