Cryoablation is in clinical trial phases or off-lable (FDA) uses, although it has been used for years in renal cell cancer, liver, lung metastasis, etc. If your friend's child can come to US, there are several hospitals are doing this, including our hospital. Depends on the place of the giant cell tumor and size, several cryoprobs might have to be used. They are about $800.00 per probe. It will be done under CT or MRI monitoring.
It just so happened that EndoCare, the company makes the cryoprobs, is hosting a dinner tonight (28th) for all the US cryoablation guys in Chicago during the annule RSNA meeting. You can go to RSNA.org and find information in Interventional radiology section of the meeting.
Hope that helps. Sorry for the delays -- I do not come very often.