# EORTC 22033-26033

Source: https://onco.cc/trials/eortc-22033/  
OnCo record `eortc-22033` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

EORTC 22033 asked whether temozolomide could replace radiotherapy as the first treatment for high-risk low-grade glioma and found no difference in progression-free survival, with the molecular subtype mattering more than the choice of treatment.

## Summary

EORTC 22033-26033 randomised 477 adults with high-risk low-grade glioma to 50.4 Gy radiotherapy or dose-dense temozolomide for up to a year. Median progression-free survival was 46 months with radiotherapy and 39 months with temozolomide (hazard ratio 1.16, not significant); IDH-mutant tumours without 1p/19q co-deletion did better with radiotherapy, and health-related quality of life did not differ (Baumert and colleagues, Lancet Oncology 2016). Radiotherapy followed by chemotherapy (as in RTOG 9802) remains the standard.

## Fields

- Kind: Trial
- Status: negative
- Last checked: 2026-09-17
- Tags: radiation-wave4
- Registry id: NCT00182819
- Phase: 3
- Setting: High-risk low-grade glioma: radiotherapy versus temozolomide alone as first treatment
- Sponsor: EORTC
- Enrolled: 477
- Result: Median progression-free survival 46 (radiotherapy) vs 39 months (temozolomide), no significant difference.

## Sources

- ClinicalTrials.gov NCT00182819: https://clinicaltrials.gov/study/NCT00182819
- Lancet Oncology 2016: https://doi.org/10.1016/S1470-2045(16)30313-8

## Connected records

- cancers: [Brain and spinal cord tumours (all types)](https://onco.cc/cancers/brain-tumours/), [Glioma & glioblastoma](https://onco.cc/cancers/glioblastoma/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)
- drugs: [Temozolomide](https://onco.cc/drugs/temozolomide/)

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