Medical notes [gleaned from the Internet]

Gamma Knife radiosurgery is very attractive in children with complex deep seated AVMs. Given their long period of risk for recurrent hemorrhage, 25 to 50 percent chance of size increase and tendency toward seizures, observing these lesions and taking no treatment action is not very attractive.

A multidisciplinary team of neurosurgeons, neuroradiologists, neurologists and neuropsychologists is involved in discussing the case, in order to develop an appropriate treatment plan.

Radiosurgery success is inversely related to the size and flow rate of AVMs. The usual time to resolution and occlusion in adults is two to three years for AVMs approximately 3cm in size [Rosie's AVM is 1.5cm]. For reasons as yet unclear, children have a shorter time to obliteration of the AVM after radiosurgery treatment than adults. It is not unusual to see a child's AVM disappear in less than one year and even six months past radiosurgery. For lesions 3cm or less, the rate of complete occlusion approaches 80 percent with a less than 1 percent treatment mortality [death] and less than 3 percent treatment morbidity [complication].

Where appropriate with AVMs, radiosurgery is easy on the child, cost effective and allows a rapid return to all activities with minimal risk.

The effect of the focused radiation on the AVM is realized over many months. While the precise mechanism of radiosurgery's action on the AVM is still not clearly understood, it is thought to act on the endothelial cells lining its blood vessels. These cells tend to multiply after radiosurgery and then become thrombolytic or clot-producing. These clots diminish blood flow through the tangle of vessels, thereby reducing the risk of hemorrhage.

Successive MRIs and angiograms allow neurosurgeons and neuroradiologists to monitor blood flow through the AVM and observe its decrease in size. The size decreases over a period of one to three years. Occasionally, further radiosurgerical treatment is required for large AVMs after two or three years of observation. Research suggests the obliteration rate for small AVMs treated radiosurgically to range between 80 and 90 percent upon two-year follow-up.

Gamma Knife radiosurgery is playing a larger role than ever in children with specific neurosurgical disorders and tumors. It is likely its use will expand in the treatment of both low-grad and malignant intracranial tumors. Its use as an adjunct treatment to surgery and external beam radiation has become more defined in recent years. In some instances, it may replace surgery and/or standard fractionated (over time) radiation therapy. It will remain the gold standard for treating many AVMs.

In plain language. With diagrams.

Peter, Wilma, and Rosie met with Miss Wirginia Maixner today.

Rosie wanted one more ride in the wheelchair we had borrowed but never used before we returned it.

Peter and Rosie made good use of the facilities in the waiting room.

Wirginia did some of the little tricks we got used to in hospital to see if Rosie's right side had improved and observed that her right arm strength and control was pretty much back to normal. She checked Rosie's field of vision and found that to be the same ie no right peripheral - confirmed by Rosie. The reason for the vision change is not known definitively - could be to do with pressure from the swelling or could be to do with changes in blood flow caused by the changes occurring round the AVM and aneurism ie something vascular. Wirginia was pleased with Rosie's progress and declared that she's fine to go to school by herself as normal with the exception of avoiding contact sports for the moment. Rosie's Principal also wants her to not do PE or any sports in the short-term. Rosie seems to have accepted that verdict with her usual calm, although she was a bit disappointed to be missing her favourite event, the cross country run which she won in her age group last year. Wirginia said swimming is fine and exertion in itself is not a problem so normal running around the playground is not an issue. She answered all our questions clearly and in plain language with diagrams so we have a better understanding of the proposed treatment and the structure and behaviour of Rosie's AVM and aneurism - too much detail to attempt here. The complete picture in actuality will be revealed after next Wednesday's MRI scan. Rosie will need to leave school that day after special maths and before Ensemble in order to lie completely still for half an hour or so in the MRI machine.

On the Thursday morning immediately following we will visit Wirginia again and she will interpret the results of the MRI. The following Wednesday, the 23rd of March, we are to show up at the Peter MacCallum Cancer Centre, where they have the facilities to perform radiation treatment (she doesn't have cancer!). We will then discuss the treatment with the doctors there.
After our appointment, the girls joined Sandra, Wilma's best friend from primary school days for lunch. Another old friend, Meg Hansen, who happens to be Jessye's Principal at Lauriston Girls' School joined them at Gorgio's in Armadale. Rosie had bowties carbonara. We gave school a miss today.

Later we were visited by Stephen and Robyn, more old Kiwi friends who had flown to Melbourne from Sydney to attend a funeral which turned out to be thick with neurologists.

After pizza from our local the ladies took the cats to the vet for their annual tuneup. While we waited Rosie went into the little kids' cage and tickled her fancy playing with numbers following yesterday's maths lesson on the order of operations while Sophie serenaded with a Ray Charles impersonation.