1. A Late Haemorrhagic Complication in a Cured Arterio- Venous Malformation D. Le Feuvre, A. Taylor

2. 19 year old male presents with a grand mal siezure in November 2004 MRI shows a left-sided parieto- occipital AVM

3. DSA 2004

4. Decision to treat with radiosurgery in March 2005 Linac 23 Gy with 18.5Gy @ 80%

5. In January 2007 had another DSA to assess result of the radiosurgery

6. 6 DSA 2007

7. DSA PRE and POST Radiosurgery

8. November 2009 Presented with sudden onset headache and hemi-sensory loss on the right

9. MRI T1 without and with gadollinium

10. MRI Flair and Gradient Echo

11. Why so much mass effect and oedema on the MRI? Radionecrosis - but unusual so extensive and so late Venous compromise - the radiosurgery closed some normal veins or the brain was utilising the vein the AVM used to drain Radionecrosis - but unusual so extensive and so late Venous compromise - the radiosurgery closed some normal veins or the brain was utilising the vein the AVM used to drain

12. Venous drainage

13. Venous drainage looks normal Haematoma/heamorrhage from cavernoma but small amount of blood on T1 Venous drainage looks normal Haematoma/heamorrhage from cavernoma but small amount of blood on T1

14. Patient taken to theatre because of ongoing headache, failure of hemi- sensory loss to recover and extensive oedema

16. The lesion fulfils Cahan’s criteria 1) a latency interval between radiation and lesion development- in our case just over 4 1/2 years 2) the lesion arose in the radiation field 3) the lesion was histologically distinct from from the originally treated lesion 4) the patient was not be genetically predisposed to the lesion he develop 1) a latency interval between radiation and lesion development- in our case just over 4 1/2 years 2) the lesion arose in the radiation field 3) the lesion was histologically distinct from from the originally treated lesion 4) the patient was not be genetically predisposed to the lesion he develop

17. CONCLUSION Radiosurgery is safe Incidence of radiosurgially induced pathology is under reported Oedema/cerebral swelling in the late post- radiosurgical period has different causes Radiosurgery is safe Incidence of radiosurgially induced pathology is under reported Oedema/cerebral swelling in the late post- radiosurgical period has different causes