Apparent diffusion coefficient mapping in medulloblastoma predicts non-infiltrative surgical planes

Area of Science:

• Neuro-oncology
• Radiology
• Pediatric Neurosurgery

Background:

• Surgical planning for posterior fossa tumors requires identifying tumor planes to minimize damage to critical brain structures.
• Magnetic resonance imaging (MRI) provides limited information on tumor infiltration in pediatric medulloblastomas.
• Apparent diffusion coefficient (ADC) maps show diffusion restriction in medulloblastomas, suggesting potential for predicting tumor-brainstem interfaces.

Purpose of the Study:

• To investigate the predictive value of ADC maps in identifying infiltrative and non-infiltrative planes between medulloblastomas and the brain stem/cerebellar peduncles.
• To assess the utility of ADC maps in preoperative surgical planning for pediatric medulloblastoma.

Main Methods:

• Retrospective review of 34 pediatric patients with medulloblastoma who underwent surgical resection (2004-2012).
• An experienced pediatric neuroradiologist assessed tumor planes on preoperative MRI and ADC maps.
• Intraoperative surgical findings were documented and compared with radiographic assessments to determine predictive accuracy.

Main Results:

• Twenty-six patients met inclusion criteria for ADC map analysis.
• Positive predictive values for ADC maps ranged from 69-88%, and negative predictive values ranged from 70-89%.
• Sensitivity for detecting tumor invasion approached 93%, with specificity around 78%.

Conclusions:

• ADC maps are valuable tools for predicting tumor infiltration at the brain stem and cerebellar peduncle interface in medulloblastomas.
• Incorporating ADC map evaluation into preoperative assessments can significantly aid surgical resection planning for pediatric medulloblastoma patients.