Keywords

  • Demographics: Male; 32 years

  • Initial Presentation: Seizures for 2 months before radiosurgery treatment

  • Diagnosis: Parieto-occipital AVM

  • Pre-radiosurgery Treatment: Endovascular embolization; 3 weeks before radiosurgery treatment

  • Pre-radiosurgery Presentation: Seizures (generalized tonic-clonic)

  • Radiosurgery Treatment:

    Adjunctive; Linac-based SRS for post-embolization residual, left, parieto-occipital AVM

  • Radiosurgery Dosimetry:

    • Target volume: 2.8 cc

    • Marginal dose: 20.0 Gy

    • Marginal isodose: 80%

    • Maximum dose: 25.0 Gy

    • Minimum dose: 18.1 Gy

    • Average dose: 23.9 Gy

    • Number of isocenters: 1

  • Follow-Up Period: 82 months post-SRS

  • Clinical Outcome:

    • 6 months post-SRS: Persistent seizures with medication

    • 18 months post-SRS: Decreased seizures frequency with medication

    • 30 months post-SRS: Controlled seizures with medication

    • 48 months post-SRS: Controlled seizures with lower dose of medication

    • 82 months post-SRS: Sustainable control of seizures with lower dose of medication

  • Complications: None

  • Radiological Outcome:

    • 6 months post-SRS (MRI): Stationary size of AVM nidus

    • 12 months post-SRS (MRI):

      • Decrease in size of AVM nidus

      • Appearance of perinidal high signal in T2 and FLAIR studies, denoting vasogenic edema

      • Appearance of perinidal enhancing lesion, in T1 Gadolinium-enhanced study, denoting radiation-induced parenchymal changes

    • 18 months post-SRS (MRI):

      • More decrease in size of AVM nidus

      • Increased perinidal high signal in T2 and FLAIR studies

      • Increase in size of perinidal enhancing lesion, in T1 Gadolinium-enhanced study

    • 24 months post-SRS (MRI):

      • More decrease in size of AVM nidus

      • Resolving perinidal high signal in T2 and FLAIR studies

      • Decrease in size of perinidal enhancing lesion, in T1 Gadolinium-enhanced study

    • 36 months post-SRS (MRI):

      • Stationary decreased size of AVM nidus

      • Mild residual perinidal high signal in T2 and FLAIR studies

      • Resolution of perinidal enhancement, in T1 Gadolinium-enhanced study

    • 36 months post-SRS (CTA): Residual small AVM nidus

    • 48 months post-SRS (CTA): Residual smaller AVM nidus

    • 82 months post-SRS (CTA): Residual much smaller AVM nidus

  • Post-radiosurgery Treatment: Continued anti-convulsant medication. The patient is scheduled for conventional cerebral angiography and will be offered surgery, repeat radiosurgery, or endovascular embolization for the post-radiosurgery residual, non-obliterated, small AVM nidus

6-parts of brain scan before embolization. An arrow points at the bottom left corner of the brain in the first five scans. An arrow points to the middle right in the last scan.
3-part brain scan of veins in the brain before embolization.
A 3-part brain scan of veins in the brain 3 weeks after embolization before S R S.
2-part M R I image of the brain on the treatment day. An arrow in the right image points at the embolization.
4-parts of M R I image of the brain after 6 months F slash U. An arrow in the right image points at the embolization.
7-parts of M R I image of the brain after 12 months F slash U. An arrow points at the embolization. The scans include top and side views.
7-parts of M R I image of the brain after 18 months F slash U. An arrow points at the embolization. The scan includes top and sideways views.
7-parts of M R I image of the brain after 24 months F slash U. An arrow points at the embolization. The scan includes top and sideways views.
7-parts of M R I image of the brain after 36 months F slash U. An arrow points at the embolization. The scan includes top and sideways views.
6-parts of brain image scans after 36 months F slash U. 3 arrows point to the embolization in the top 3 images. The bottom 3 images depict brain veins.
6-part of scans after 48 months F slash U. Top 3 images are brain scans. The bottom 3 images are brain veins.
6-parts of brain scans after 82 months F slash U. Arrows point to the embolization in the top 3 images. The bottom 3 images depict brain veins.
9-part brain image scans of intravenous structure. The top, middle, and bottom 3 images before S R S, 36 months F slash U, and 48 months F slash U.
9-part brain image scans of intravenous structure. The top, middle, and bottom 3 images before embolization, S R S, and 82 months F slash U.