Radiation-induced gliomas are a rare complication of cranial irradiation, occurring in less than 3% of cases 15 years post treatment. Glioblastomas correspond to three-quarters of all radiation induced gliomas.
The risk of developing a secondary CNS cancer following radiation exposure has been well established, especially with meningiomas. However, it is important to highlight that the absolute risk of developing a radiation-induced tumour after radiotherapy to the CNS remains relatively low, and usually the overall benefits of the treatment outweigh this possible negative complication.
Studies have shown that the estimated cumulative risk for malignant brain tumours is 0.5-2.7% at 15 years post radiotherapy. 75% of all radiation induced gliomas are glioblastomas and 25% are lower grade astrocytomas 3.
Microarray gene-expression profiling has been used experimentally to differ radiation-induced from spontaneous glioblastomas 1.
Radiation-induced malignancies have been defined as those tumours which fulfill the following criteria 2:
- tumour in a previously irradiated area
- sufficient latency time between the original and new tumors
- new tumour must has a distinct histology from the original
- no history of disease predisposing to tumour development
- WHO classification of CNS tumours
- WHO grading of CNS tumours
- VASARI MRI feature set
- diffuse astrocytoma grading
- grade I:
- grade II:
- grade III
- anaplastic astrocytoma
- anaplastic oligodendroglioma
- grade IV:
- glioblastoma vs cerebral metastasis
- radiation-induced gliomas
- gliomatosis cerebri (growth pattern)
- specific locations
- treatment response
- Stupp protocol
- glioma treatment response assessment in clinical trials
- multicentric glioblastoma
- multifocal glioblastoma
- prognostic genetic markers
- 1. Madden JR, Addo-Yobo SO, Donson AM et-al. Radiation-induced glioblastoma multiforme in children treated for medulloblastoma with characteristics of both medulloblastoma and glioblastoma multiforme. J. Pediatr. Hematol. Oncol. 2010;32 (7): e272-8. doi:10.1097/MPH.0b013e3181e51403 - Pubmed citation
- 2. Cahan WG, Woodard HQ, Higinbotham NL et-al. Sarcoma arising in irradiated bone: report of eleven cases. 1948. Cancer. 1998;82 (1): 8-34. Pubmed citation
- 3 Paulino AC, Mai WY, Chintagumpala M et-al. Radiation-induced malignant gliomas: is there a role for reirradiation?. Int. J. Radiat. Oncol. Biol. Phys. 2008;71 (5): 1381-7. doi:10.1016/j.ijrobp.2007.12.018 - Pubmed citation
- 4. Prasad G, Haas-Kogan DA. Radiation-induced gliomas. Expert Rev Neurother. 2009;9 (6): 1511-7. doi:10.1002/pmic.200800802 - Free text at pubmed - Pubmed citation