Faculty Bibliography

BACKGROUND: A retrospective study of patients undergoing stereotactic radiosurgery for one to four brain metastases from nonsmall lung cell carcinoma (NSCLC) was performed to document outcomes and risks. METHODS: Seventy-seven patients underwent radiosurgery during a 7-year interval; 71 also underwent whole brain radiation therapy. Univariate and multivariate analyses were used to determine significant prognostic factors affecting survival. RESULTS: The overall median survival was 10 months after radiosurgery, and 15 months from the diagnosis of brain metastases. Five factors significantly affected survival: extent of systemic disease, presence of a neurologic deficit, size of the intracranial tumor, initial imaging appearance of intratumoral necrosis, and initial resection of the primary tumor of the chest. Median survival time was 26 months in a subgroup of patients with no extracranial metastases, no neurologic deficits, and a small tumor without necrosis. The authors evaluated 91 tumors with imaging. Local tumor control was achieved in 77 lesions (85%) and tumoral radiation necrosis developed in 4 lesions (4.4%). Nineteen new metastatic tumors developed during the observation interval. CONCLUSIONS: Stereotactic radiosurgery for NSCLC brain metastases is effective and is associated with few complications. The early detection of brain metastases and treatment with radiosurgery combined with radiation therapy provide the opportunity for extended high quality survival.

OBJECTIVE: During an 8-year interval, we evaluated the survival benefit of stereotactic radiosurgery performed in 64 patients with glioblastomas multiforme (GBM) and 43 patients with anaplastic astrocytomas (AA). METHODS: Adjuvant radiosurgery was performed either before disease progression or for recurrent tumor at the time of disease progression. Clinical and imaging follow-up data were obtained for all patients. The diagnosis of GBM was obtained by performing craniotomies in 41 patients and by performing stereotactic biopsies in 23. The diagnosis of AA was obtained by performing craniotomies in 19 patients (44%) and by performing biopsies in 24. RESULTS: Of the entire series, the median survival time after initial diagnosis for patients with GBM was 26 months (standard deviation [SD], 19 mo; range, 5-79 mo) and the median survival time after radiosurgery was 16 months (SD, 16 mo; range, 1-74 mo). The 2-year survival rate was 51%. No survival benefit was identified for patients who underwent intravenously administered chemotherapy in addition to radiosurgery (P = 0.97). After undergoing radiosurgery, 12 patients (19%) underwent craniotomies and resections and 4 (6%) underwent subsequent radiosurgery for regional or remote recurrence. For 45 patients who underwent radiosurgery as part of the initial management plan, the median survival time after diagnosis was 20 months. Of the entire series, the median survival time after diagnosis for patients with anaplastic astrocytomas was 32 months (SD, 23 mo; range 5-96 mo) and the median survival time after radiosurgery was 21 months (SD, 18 mo; range 3-93 mo). The 2-year survival rate was 67%. Ten patients (23%) underwent subsequent craniotomies at a mean of 8 months after initial surgery, and two underwent subsequent radiosurgery. There was no acute neurological morbidity after radiosurgery. Histologically proven radiation necrosis occurred in one patient with GBM (1.6%) and two patients with AA (4.7%). For 21 patients for whom radiosurgery was part of the initial management plan, the median survival time after diagnosis was 56 months. CONCLUSION: In comparison to historical controls, improved survival benefit after radiosurgery was identified for patients with GBM and patients with AA. Although this survival benefit may be related to our selection of patients for radiosurgery based on their having smaller tumor volumes, no selection was made based on location. We observed that radiosurgery was safe and well tolerated. Its effectiveness as an adjuvant therapy deserves a properly stratified randomized trial.

Sphenopalatine neuralgia is a rare craniofacial pain syndrome that is characterized by unilateral pain in the orbit, mouth, nose, and posterior mastoid process. During attacks of pain, vasomotor activity often results in ipsilateral nasal drainage, eye irritation, and lacrimation. The authors present a patient with a 15-year history of sphenopalatine neuralgia who underwent stereotactic radiosurgery targeted at the sphenopalatine ganglion, with initial pain relief, and repeated radiosurgery 17 months later for partial pain recurrence. Two years following radiosurgery, the patient is pain free, no longer suffering from nasal discharge and eye irritation.

OBJECTIVE: Future improvements in the results of stereotactic radiosurgery will be related to better patient selection, dose planning, radiosensitization of the target, and, possibly, protection of the brain surrounding the target. 21-Aminosteroids may provide protection against brain radiation injury by inhibition of lipid peroxidation and a selective action on vascular endothelium. We hypothesized that the 21-aminosteroid U-74389G would reduce radiosurgery-related brain injury without attenuating the target volume response. METHODS: One hundred and forty-five rats were divided into four experimental groups before undergoing radiosurgery: control (n = 47); low-dose U-74389G (5 mg/kg of body weight, n = 30); high-dose U-74389G (15 mg/kg, n = 20); and methylprednisolone (2 mg/kg, n = 48). The drug was administered 1 hour before radiosurgery (4-mm gamma knife collimator) of the normal rat frontal lobe (single-fraction maximum doses of 50, 100, or 150 Gy) was performed. All brains underwent histological examination at 90 or 150 days to evaluate the diameters of necrosis and the findings of radiation-induced vasculopathy, brain edema, and gliosis. RESULTS: None of the animals that received 50-Gy radiation developed histological changes, whereas all of the animals that received 150-Gy radiation developed radiation necrosis without drug-induced protection from vascular changes or edema. In animals receiving 100-Gy radiation, high-dose aminosteroid reduced radiation-induced vasculopathy at 90 days (P = 0.06) and at 150 days (P = 0.02) and prevented regional edema at 90 days (P = 0.01) and at 150 days (P = 0.03). Low-dose aminosteroid and corticosteroid provided no protection. CONCLUSION: The 21-aminosteroid U-74389G provided protection after a single intravenously administered dose of 15 mg/kg against radiation-induced vasculopathy and edema. High-dose 21-aminosteroids seem to have optimal properties for radiosurgery, surrounding brain protection without reducing the therapeutic effect desired within the target volume.