Faculty Bibliography

PURPOSE: To evaluate tumor control and outcome from radiosurgery of meningiomas diagnosed by imaging without pathologic verification. METHODS AND MATERIALS: A total of 219 meningiomas diagnosed by imaging criteria underwent gamma knife radiosurgery to a median marginal tumor dose of 14 Gy (range 8.9-20), a median treatment volume of 5.0 cm(3) (range 0.47-56.5), and a median maximal dose of 28 Gy (range 22-50). The median follow-up was 29 months (range 2-164). RESULTS: Tumor progression developed in 7 cases, 2 of which turned out to be different tumors (metastatic nasopharyngeal adenoid cystic carcinoma and chondrosarcoma). One tumor was controlled, but the development of other brain metastases suggested a different diagnosis. The actuarial tumor control rate was 93.2% +/- 2.7% at 5 and 10 years. The actuarial rate of identifying a diagnosis other than meningioma was 2.3% +/- 1.4% at 5 and 10 years. The actuarial rate of developing any postradiosurgical injury reaction was 8.8% +/- 3.0% at 5 and 10 years. No pretreatment variables correlated with tumor control in univariate or multivariate analysis. The risk of postradiosurgery sequelae was lower (5.3% +/- 2.3%) in patients treated after 1991 (with stereotactic MRI and lower doses; p = 0.0104) and tended to increase with treatment volume (p = 0.0537). CONCLUSION: Radiosurgery of meningioma diagnosed by imaging without tissue confirmation is associated with a high rate of tumor control and acceptable morbidity but carries a small risk (2.3%) of an incorrect diagnosis.

OBJECTIVE: Whole brain radiotherapy (WBRT) provides benefit for patients with brain metastases but may result in neurological toxicity for patients with extended survival times. Stereotactic radiosurgery in combination with WBRT has become an important approach, but the value of WBRT has been questioned. As an alternative to WBRT, we managed patients with stereotactic radiosurgery alone, evaluated patients' outcomes, and assessed prognostic factors for survival and tumor control. METHODS: One hundred seventy-two patients with brain metastases were managed with radiosurgery alone. One hundred twenty-one patients were evaluable with follow-up imaging after radiosurgery. The median patient age was 60.5 years (age range, 16-86 yr). The mean marginal tumor dose and volume were 18.5 Gy (range, 11-22 Gy) and 4.4 ml (range, 0.1-24.9 ml). Eighty percent of patients had solitary tumors. RESULTS: The overall median survival time was 8 months. The median survival time in patients with no evidence of primary tumor disease or stable disease was 13 and 11 months. The local tumor control rate was 87%. At 2 years, the rate of local control, remote brain control, and total intracranial control were 75, 41, and 27%, respectively. In multivariate analysis, advanced primary tumor status (P = 0.0003), older age (P = 0.008), lower Karnofsky Performance Scale score (P = 0.01), and malignant melanoma (P = 0.005) were significant for poorer survival. The median survival time was 28 months for patients younger than 60 years of age, with Karnofsky Performance Scale score of at least 90, and whose primary tumor status showed either no evidence of disease or stable disease. Tumor volume (P = 0.02) alone was significant for local tumor control, whereas no factor affected remote or intracranial tumor control. Eleven patients developed complications, six of which were persistent. Nineteen (16.5%) of 116 patients in whom the cause of death was obtained died as a result of causes related to brain metastasis. CONCLUSION: Brain metastases were controlled well with radiosurgery alone as initial therapy. We advocate that WBRT should not be part of the initial treatment protocol for selected patients with one or two tumors with good control of their primary cancer, better Karnofsky Performance Scale score, and younger age, all of which are predictors of longer survival.

In this study, we evaluated the results in four patients with nongerminomatous germ cell tumors (NGGCT) of the pineal region. All underwent radiosurgery in conjunction with surgical resection, fractionated radiotherapy or chemotherapy. Four male patients with pineal region NGGCT were treated with radiosurgery. The mean age was 16.5 years. Three patients had histological confirmation by stereotactic biopsy or craniotomy prior to radiosurgery. One patient was diagnosed by serum and CSF tumor markers. The mean tumor volume was 10.5 cm(3). Radiosurgery was performed with mean maximum and marginal doses of 28 and 14 Gy, respectively. At last follow-up, three patients were alive and one was dead. The mean follow-up after diagnosis and after radiosurgery was 34 and 25 months, respectively. At last follow-up, two tumors had regressed, one was unchanged and one had progressed. No patient had complications after radiosurgery. Radiosurgery can play an important adjuvant role for NGGCT patients who also undergo multimodal management. In the case of prepubertal patients, radiosurgery may play an important role by reducing the radiation dose to the surrounding normal brain.

OBJECT: Nonfunctioning pituitary adenomas comprise approximately 30% of all pituitary tumors. The purpose of this retrospective study was to evaluate the efficacy and role of gamma knife surgery (GKS) in the treatment of these lesions. METHODS: The authors conducted a review of cases in which GKS was performed at the University of Pittsburgh between 1987 and 2001. Forty-six patients with nonfunctioning pituitary adenomas and with at least 6 months of follow- up data were identified. In 41 of these patients some form of prior treatment such as transsphenoidal resection, craniotomy and resection, or conventional radiation therapy had been conducted. Five patients were deemed ineligible for microsurgery, and GKS served as the primary treatment modality. Endocrinological, ophthalmological, and radiological responses were evaluated. The mean radiation dose to the margin was 16 Gy. In all patients with microadenomas and 91% of those with macroadenomas tumor control was demonstrated after radiosurgery. Gamma knife surgery had essentially equal efficacy in terms of achieving tumor control in cases of adenomas with cavernous sinus invasion and suprasellar extension. No new endocrinopathies were noted following radiosurgery. In two patients, however, tumor growth and decline in visual function occurred. CONCLUSIONS: Gamma knife surgery is safe and effective in treating nonfunctioning pituitary adenomas. Radiosurgery may serve as a primary treatment modality in some or as a salvage treatment in others. Treatment must be tailored to meet the patient's symptoms, overall health, and tumor morphometry.