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Updated: Jun 17, 2026
Quantifying Cognitive Decrements Caused by Cranial Radiotherapy
Published on: October 18, 2011
Impact of radiation avoidance on survival and neurocognitive outcome in infant medulloblastoma
L Lafay-Cousin1, E Bouffet, C Hawkins
1Department of Pediatric Oncology and Bone Marrow Transplantation, Alberta Children's Hospital, Calgary, AB. lucie.lafay-cousin@albertahealthservices.ca
Insights
Avoiding conventional craniospinal irradiation (CSI) in infants with medulloblastoma may preserve neurocognitive function. This study compared survival and neurocognitive outcomes in young children treated with or without CSI.
Area of Science:
- Pediatric Oncology
- Neuro-oncology
- Radiation Oncology
Background:
- Concerns exist regarding long-term neurocognitive sequelae from radiotherapy in young children.
- Medulloblastoma treatment in infants has evolved, shifting away from routine craniospinal irradiation (CSI).
Purpose of the Study:
- To compare survival and neurocognitive outcomes in infants with medulloblastoma treated with adjuvant conventional CSI versus reduced or no radiotherapy.
- To evaluate the impact of changing treatment philosophies on outcomes for this patient population.
Main Methods:
- Retrospective review of 29 patients aged 3 years or younger diagnosed between 1985 and 2007.
- Comparison of outcomes between children receiving adjuvant radiotherapy with chemotherapy and those receiving chemotherapy alone post-surgery.
Main Results:
- Five-year event-free survival was 35.9% and overall survival was 50.2%.
- Patients treated with chemotherapy alone showed improved intellectual function over time.
- Conventional CSI was associated with significantly lower intelligence quotient scores and academic performance, excluding receptive vocabulary.
Conclusions:
- Avoiding conventional CSI in very young medulloblastoma patients appears to preserve neurocognitive function.
- Future infant medulloblastoma protocols should prioritize neurocognitive evaluation.
Purpose:
Concerns about radiotherapy-related neurocognitive sequelae in young children have led to deferral or avoidance of radiation in contemporary treatment for this fragile group of patients. We compared survival and neurocognitive outcome in two groups of infants with medulloblastoma who received adjuvant conventional craniospinal irradiation (CSI) or reduced or no radiotherapy during an era of change in the philosophy of infant medulloblastoma treatment.
Patients And Methods:
From 1985 to 2007, 29 patients 3 years of age or younger were diagnosed and treated with curative intent in our institution. Children treated before 1994 received adjuvant radiation with chemotherapy; subsequently, radiation was prescribed essentially for disease progression or relapse.
Results:
Median age at diagnosis was 24 months (range: 1-36 months); 15 patients (52%) presented with metastatic disease at diagnosis. As part of initial treatment, 8 children received adjuvant radiotherapy with chemotherapy, and 21 children received postoperative chemotherapy only. Five children treated with chemotherapy alone are in prolonged remission. The 5-year event-free and overall survivals were 35.9% +/- 9.8% and 50.2% +/- 9.6% respectively. Extent of resection, metastatic status, and desmoplastic histology were not found to be significant prognostic factors. On serial neurocognitive evaluations, patients treated with chemotherapy with or without reduced radiotherapy demonstrated improvement of intellectual function over time. Patients treated with conventional csi exhibited significantly lower intelligence quotient scores and academic performance, with the exception of receptive vocabulary.
Conclusions:
Avoidance of conventional CSI in treatment of very young children with medulloblastoma appears to be associated with a preserved neurocognitive profile. Neurocognitive evaluation should be integrated into the primary objectives of future infant protocols.
