The stereotactic volumetric information: Its role in two-step resection of brainstem and thalamic giant tumor. Report of three cases and technical note.

BACKGROUND A compact intracerebral tumoral lesion is usually considered to be completely resectable. Nevertheless, radical resection of a huge lesion located in a critical area may damage the surrounding compressed brain tissue. In cases with a good prognosis, a two-step removal appears to be a safer strategy. METHODS In three cases, two with huge brain stem lesions and one with a thalamic lesion, a two-step volumetric stereotactic resection was planned. This strategy allowed us to evaluate the amount of tumor to be removed during the first procedure and to have, during the second operation, an exact definition of the reduced mass with regard to the scar tissue and postoperative adhesions. Furthermore, we avoided significant shifting of the cerebral structures during both procedures. RESULTS There was a very good final recovery in the cases with brain stem lesions and a minimal deficit in the patient with the thalamic lesion. The patient with a mesencephalic lesion remained comatose for almost 2 days after the first procedure, confirming our fears about too radical a one-step resection. CONCLUSIONS We think that by using current techniques, it is possible to remove a well circumscribed lesion regardless of its position. This is probably easier with giant lesions where a safe trajectory can be planned. In these cases, with lesions located in very critical areas but with a good prognosis, a two-step resection appears to be a good option. (C) 1999 by Elsevier Science Inc.