Faculty Bibliography

OBJECT: The aim of this study was to evaluate the outcomes of Gamma Knife surgery (GKS) when used for patients with intractable cluster headache (CH). METHODS: Four participating centers of the North American Gamma Knife Consortium identified 17 patients who underwent GKS for intractable CH between 1996 and 2008. The median patient age was 47 years (range 26-83 years). The median duration of pain before GKS was 10 years (range 1.3-40 years). Seven patients underwent unsuccessful prior surgical procedures, including microvascular decompression (2 patients), microvascular decompression with glycerol rhizotomy (2 patients), deep brain stimulation (1 patient), trigeminal ganglion stimulation (1 patient), and prior GKS (1 patient). Fourteen patients had associated autonomic symptoms. The radiosurgical target was the trigeminal nerve (TN) root and the sphenopalatine ganglion (SPG) in 8 patients, only the TN in 8 patients, and only the SPG in 1 patient. The median maximum TN and SPG dose was 80 Gy. RESULTS: Favorable pain relief (Barrow Neurological Institute Grades I-IIIb) was achieved and maintained in 10 (59%) of 17 patients at a median follow-up of 34 months. Three patients required additional procedures (repeat GKS in 2 patients, hypothalamic deep brain stimulation in 1 patient). Eight (50%) of 16 patients who had their TN irradiated developed facial sensory dysfunction after GKS. CONCLUSIONS: Gamma Knife surgery for intractable, medically refractory CH provided lasting pain reduction in approximately 60% of patients, but was associated with a significantly greater chance of facial sensory disturbances than GKS used for trigeminal neuralgia.

Stereotactic radiosurgery is used for many neoplastic, vascular, and functional disorders of the nervous system. The expanded use of this technique over the past two decades is based mainly on the spectrum of clinical research performed for these disorders. From case series to randomized trials, the safety and efficacy of radiosurgery is well documented. In this report, we discuss the key indications for radiosurgery and the kinds of research performed in this field.

BACKGROUND: A therapeutic radiosurgery procedure usually follows a separate diagnostic stereotactic procedure after days or weeks. OBJECTIVES: To define the clinical reliability, safety, and cost implications of same-day diagnostic stereotactic biopsy and therapeutic radiosurgery. METHODS: During an 8-year interval, 26 patients underwent stereotactic brain biopsy followed by immediate therapeutic stereotactic radiosurgery in a single-day combined procedure. The intraoperative diagnosis was determined using standard histopathological techniques. Diagnostic accuracy, hospital costs, and contribution margins associated with this treatment strategy were compared to those of 26 case-matched patients (controls) who underwent a stereotactic diagnostic procedure followed by a separate-day outpatient SRS procedure within 6 weeks during the same time interval. RESULTS: The intraoperative diagnosis correlated with the final histopathological diagnosis in 96% of the patients. Biopsy-related morbidity did not occur in this series. The mean total costs of same-day patients was significantly lower than the costs of patients who had two-stage procedures (USD 9,077 +/- 2,366 vs. 11,284 +/- 3,025; p = 0.008). The net contribution to the hospital margin of USD 13,736 was not significantly different between the two management strategies. CONCLUSIONS: The advantages of the same-day approach included a single stereotactic head frame application, reduced total admission time, consecutive histopathological diagnosis and therapy in a single hospital admission, and reduced total hospital costs. For patients who are highly suspected to have a brain tumor for which SRS is likely to be an effective therapeutic strategy, same-day diagnostic stereotactic biopsy followed by therapeutic SRS proved to be a safe, reliable, and cost-effective management strategy.