Are Dual-Phase ¹⁸F-Fluorodeoxyglucose PET-mpMRI Diagnostic Performances to Distinguish Brain Tumour...

Area of Science:

• Neuro-oncology
• Radiology
• Nuclear Medicine

Background:

• High-dose radiotherapy improves outcomes for brain tumors but can cause radionecrosis.
• Distinguishing radionecrosis from tumor recurrence is challenging due to limitations of MRI and PET-CT.
• Accurate differentiation is crucial for appropriate patient management post-radiotherapy.

Purpose of the Study:

• To evaluate the diagnostic performance of dual-phase 18F-FDG PET-mpMRI in differentiating cerebral radionecrosis from local tumor recurrence.
• To compare qualitative and semi-quantitative analyses of PET-mpMRI findings.
• To assess the technique's efficacy in patients with inconclusive MRI results after cranial radiotherapy.

Main Methods:

• Retrospective analysis of 24 lesions in 23 patients treated with cranial radiotherapy.
• Inclusion of patients with inconclusive MRI findings and a history of brain tumors (primary or metastatic).
• Assessment of lesions using qualitative and semi-quantitative dual-phase 18F-FDG PET-mpMRI, with histopathology or 3-month follow-up as the gold standard.

Main Results:

• Qualitative analysis: 85.7% sensitivity, 75% specificity.
• Semi-quantitative analysis (contralateral background noise): 100% sensitivity, 50% specificity.
• Higher performance with contralateral frontal lobe noise: 92% sensitivity, 63% specificity.
• 100% sensitivity and specificity for metastatic lesions.

Conclusions:

• Dual-phase 18F-FDG PET-mpMRI demonstrates significant potential for distinguishing cerebral radionecrosis from tumor recurrence.
• The technique shows particularly high diagnostic accuracy for metastatic lesions.
• This imaging approach could improve post-radiotherapy management decisions in neuro-oncology.