RADIOSURGERY - PRELIMINARY-RESULTS IN A FRENCH CENTER

Radiosurgery (RS) is a new technique that is being developed world-wid e to treat a variety of central nervous system (CNS) diseases. We repo rt preliminary results concerning the first 35 patients treated at our institution between October 1989 and December 1990. These patients pr esented with pituitary adenomas (PA : 12 patients), primary CNS tumors with different histologies (11 patients), arteriovenous malformations (AVM : 6 patients), acoustic neurinomas (3 patients) and CNS metastas es (3 patients). All patients were treated with a linear accelerator a nd received a single dose of 20 Gy delivered on the 70 % isodose curve localized stereotactically by mean of either a CT scan or angiography . Preliminary results with a median follow-up of 26 months were as fol lows. AVM had totally disappeared in 3 patients after 12 and 17 months , and remained stable in 3 at 6 and 26 months. In 3 PA patients, the a denoma was partially regressed on the CT scan and, in 2 patients, the visual field was moderately improved ; none experienced clinical impro vement due to hormonal hypersecretion. One patient with neurinoma expe rienced clinical improvement, but the CT scan remained unchanged in th e 3 patients. Of the patients with primary or secondary tumors, 8 exhi bited a reducted lesion diameter on the CT scan, but 3 died later of p rogressive disease. Complications were not rare. In 7 patients, delaye d rections were observed : one case of cerebral edema reversed under c orticotherapy ; and 6 cases of neurological impairment due to brain ne crosis, reversed in only one. RS appears to be an interesting approach for the treatment of deeply located AVM and for small acoustic neurin omas. Its role in the treatment of other CNS diseases, such as PA and malignant tumors, remains to be determined.