⁶⁸Ga-DOTATATE PET-Based Radiation Contouring Creates More Precise Radiation Volumes for Patients With Meningioma

Area of Science:

• Neuro-oncology
• Radiology
• Nuclear Medicine

Background:

• Meningioma radiation treatment planning traditionally relies on MRI.
• Delineating gross tumor volume can be challenging with MRI, especially for skull base meningiomas or post-resection.
• ⁶⁸Ga-DOTATATE PET imaging demonstrates higher sensitivity and specificity than MRI for tumor detection.

Purpose of the Study:

• To evaluate the utility of ⁶⁸Ga-DOTATATE PET imaging in radiation treatment planning for meningiomas.
• To compare target volume delineation and disease detection between ⁶⁸Ga-DOTATATE PET and MRI.
• To test the hypothesis that PET-based planning leads to smaller radiation volumes and identifies additional disease areas.

Main Methods:

• Retrospective analysis of 25 meningioma patients who underwent both ⁶⁸Ga-DOTATATE PET and MRI.
• Blind contour delineation of gross tumor volume by 7 central nervous system specialists.
• Non-sequential contouring of both MRI and PET scans for each patient.

Main Results:

• Median PET volumes were significantly smaller than median MRI volumes across all physicians.
• ⁶⁸Ga-DOTATATE PET identified new, non-adjacent disease areas in 28% of patients not visible on MRI.
• These PET-identified areas would have been excluded from traditional MRI-based radiation volumes.

Conclusions:

• ⁶⁸Ga-DOTATATE PET imaging enhances radiation treatment planning precision for meningiomas.
• PET imaging aids in detecting occult disease not visualized by MRI.
• Prospective studies are recommended to further investigate PET-guided treatment planning.