• Wound healing impairment (risk <0.5 %): surface inflammation of the skin. In theory this inflammation can also attack the cerebral membranes or the brain itself.
• Hemorrhage (risk <1 %): When implanting the seed catheters, very small vessels in the brain, not previously evident in the MRI planning images, may be injured. If this should result in a large bleed causing paralysis or speech disturbance (risk <0.5 %) or a life-threatening condition, a further operation will be required to remove the bleed, the consequences of which may, in individual cases, not be foreseeable. So far none of the patients treated by us has suffered a fatal bleeding complication after implantation of the seed.
• CSF fistula (risk < 0.2 %): Cerebrospinal fluid (= CSF) seeping from the skin incision.
• Edema (risk <0.2 %) Swelling of the brain tissue around the implanted catheters.

Due to the radiotherapy of the tumor, patients may experience neurologic deficits (paralysis, paresthesia, seizures) and/or headaches for weeks and even months after the procedure. These disorders are caused by structural changes within the tumor triggered by the radiotherapy; in some cases fluid may collect in the brain tissue (edema) immediately adjacent to the tumor. The symptoms noted above will only appear if the edema exerts pressure on the brain tissue. These patients will then have to take cortisone medication (dexamethasone) for an extended period of time. The risk of edema formation worsening the situation is 6 to 8 %.