Faculty Bibliography

OBJECT: Pituitary adenomas are very common neoplasms, constituting between 10 and 20% of all primary brain tumors. Historically, the treatment armamentarium for pituitary adenomas has included medical management, microsurgery, and fractionated radiotherapy. More recently, radiosurgery has emerged as a viable treatment option. The goal of this research was to define more fully the efficacy, safety, and role of radiosurgery in the treatment of pituitary adenomas. METHODS: Medical literature databases were searched for articles pertaining to pituitary adenomas and stereotactic radiosurgery. Each study was examined to determine the number of patients, radiosurgical parameters (for example, maximal dose and tumor margin dose), duration of follow-up review, tumor growth control rate, complications, and rate of hormone normalization in the case of functioning adenomas. A total of 35 peer-reviewed studies involving 1621 patients were examined. Radiosurgery resulted in the control of tumor size in approximately 90% of treated patients. The reported rates of hormone normalization for functioning adenomas varied substantially. This was due in part to widespread differences in endocrinological criteria used for the postradiosurgical assessment. The risks of hypopituitarism, radiation-induced neoplasia, and cerebral vasculopathy associated with radiosurgery appeared lower than those for fractionated radiation therapy. Nevertheless, further observation will be required to understand the true probabilities. The incidence of other serious complications following radiosurgery was quite low. CONCLUSIONS: Although microsurgery remains the primary treatment modality in most cases, stereotactic radiosurgery offers both safe and effective treatment for recurrent or residual pituitary adenomas. In rare instances, radiosurgery may be the best initial treatment for patients with pituitary adenomas. Further refinements in the radiosurgical technique will likely lead to improved outcomes.

INTRODUCTION: When cancer spreads to the brain, patients and their families report a much reduced quality of life. Whole-brain radiation therapy (WBRT) and/or radiosurgery (RS) are mainstays of management for patients with metastatic brain cancer. Despite the ubiquity of this problem, little is known about the patients' perspective regarding management-related complications. To assess the patients' perspective regarding current therapeutic options, we retrospectively surveyed 200 consecutive patients who underwent radiosurgery with or without WBRT. METHODS AND MATERIALS: The survey consisted of 10 questions that sought information on quality of life, employment status, side effects (hair loss, fatigue, memory, concentration, mood, or employment), activity level, and satisfaction. RESULTS: We tabulated 104 responses (52%). WBRT was used in 69% (72 of 104); all patients had radiosurgery. After WBRT, the following were noted: hair loss (88%; total regrowth in 24%), excess fatigue (95%), problems with short-term memory (72%), long-term memory (33%), concentration (61%), and depression (54%). Sixty-three percent of patients who had WBRT thought they had side effects after treatment compared with 34% who had radiosurgery only (P <0.001). Only 5% of RS patients reported fatigue. Seventy-six percent and 56% of respondents considered RS or WBRT, respectively, a good treatment of them (P = 0.25). Only 26 patients (27%) were employed at the time of treatment and 16 remained employed (62%). Eighteen percent believed that WBRT delayed other cancer treatments. CONCLUSIONS: Patients with brain metastases often report complications of their disease or its treatment. Side effects are most pronounced in those who received WBRT. Radiosurgery had fewer reported side effects and was believed by more patients or families to be effective. Further study of clinical outcomes and quality of life is important to guide our management of patients with these common brain tumors.

OBJECT: Lung carcinoma is the leading cause of death from cancer. More than 50% of those with small cell lung cancer develop a brain metastasis. Corticosteroid agents, radiotherapy, and resection have been the mainstays of treatment. Nonetheless, median survival for patients with small cell lung carcinoma metastasis is approximately 4 to 5 months after cranial irradiation. In this study the authors examine the efficacy of gamma knife surgery for treating recurrent small cell lung carcinoma metastases to the brain following tumor growth in patients who have previously undergone radiation therapy, and they evaluate factors affecting survival. METHODS: A retrospective review of 27 patients (47 recurrent small cell lung cancer brain metastases) undergoing radiosurgery was performed. Clinical and radiographic data obtained during a 14-year treatment period were collected. Multivariate analysis was utilized to determine significant prognostic factors influencing survival. The overall median survival was 18 months after the diagnosis of brain metastases. In multivariate analysis, factors significantly affecting survival included: 1) tumor volume (p = 0.0042); 2) preoperative Karnofsky Performance Scale score (p = 0.0035); and 3) time between initial lung cancer diagnosis and development of brain metastasis (p = 0.0127). Postradiosurgical imaging of the brain metastases revealed that 62% decreased, 19% remained stable, and 19% eventually increased in size. One patient later underwent a craniotomy and tumor resection for a tumor refractory to radiosurgery and radiation therapy. In three patients new brain metastases were demonstrating on follow-up imaging. CONCLUSIONS: Stereotactic radiosurgery for recurrent small cell lung carcinoma metastases provided effective local tumor control in the majority of patients. Early detection of brain metastases, aggressive treatment of systemic disease, and a therapeutic strategy including radiosurgery can extend survival.

OBJECT: Glomus jugulare tumors are rare tumors that commonly involve the middle ear, temporal bone, and lower cranial nerves. Resection, embolization, and radiation therapy have been the mainstays of treatment. Despite these therapies, tumor control can be difficult to achieve particularly without undo risk of patient morbidity or mortality. The authors examine the safety and efficacy of gamma knife surgery (GKS) for glomus jugulare tumors. METHODS: A retrospective review was undertaken of the results obtained in eight patients who underwent GKS for recurrent, residual, or unresectable glomus jugulare tumors. The median radiosurgical dose to the tumor margin was 15 Gy (range 12-18 Gy). The median clinical follow-up period was 28 months, and the median period for radiological follow up was 32 months. All eight patients demonstrated neurological stability or improvement. No cranial nerve palsies arose or deteriorated after GKS. In the seven patients in whom radiographic follow up was obtained, the tumor size decreased in four and remained stable in three. CONCLUSIONS: Gamma knife surgery would seem to afford effective local tumor control and preserves neurological function in patients with glomus jugulare tumors. If long-term results with GKS are equally efficacious, the role of stereotactic radiosurgery will expand.