Neurofibrosarcoma

HI:
My niece who (who is living outside the US) is 14 yrs old was just diagnosed with Neurofibrosarcoma. Both biopsies confirmed it. The growth showed up 4 inches above her ear. The surgeons are going to another scrape (externally) and do another biopsy.  Then they will recommend the treatment options based on the biopsy results. No MRI or CT scans have been done.

Can a biopsy show the status of the cancer inside her head ( if it has grown inside)?
Isn't a CT Scan important.