Stereotactic drainage of brain abscesses

Between 1981 and 1986, 16 patients with brain abscesses underwent computed tomography (CT) guided stereotactic aspiration with (n = 5) or without (n = 11), catheter drainage. Infectious sources were found in 11 patients; 6 patients had concomitant immune suppression. Bacterial or mixed toxoplasmic-fungal or toxoplasmic-viral abscesses were diagnosed in 14 patients. After prolonged antimicrobial treatment, follow-up clinical and radiological evaluations confirmed abscess resolution in 12 patients. The abscess size was smaller in four patients, three of whom died 30-60 days after surgery due to overwhelming systemic opportunistic infections. One patient with a tuberculous brain abscess continued to exhibit gradual abscess regression one year after beginning three-drug antituberculous therapy. No surgical mortality occurred but two patients required evacuation of post-operative intracerebral haematomas that resulted from over-vigorous abscess aspiration. CT stereotactic drainage is a safe and effective technique to diagnose and treat brain abscesses and is mandatory for small or deep-seated lesions. Empirical therapy of suspected brain abscesses is rarely warranted in the era of CT stereotactic surgery.     

Brain surgery with image guidance: current recommendations based on a 20-year assessment.

Image guidance promotes safe and effective surgical management of a wide array of intracranial diseases. To better define the historical importance of image guidance and to assess the relative contribution of each imaging modality to the safety and efficacy of selected procedures, we reviewed our 20-year experience at a single institution. A retrospective review of our departmental surgical records was performed to identify patients who underwent brain surgery with image guidance between January 1979 and January 1999. We identified the use of intraoperative fluoroscopy, endoscopy, computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, and angiography in 7,388 patients. During this 20-year interval, advances in neuroimaging were translated into the operating room environment. Fluoroscopic guidance received the highest overall rating and was deemed critical for the performance of successful transsphenoidal surgery (n = 436) and effective percutaneous trigeminal neuralgia management (n = 1,121). Ultrasound and angiography both had limited roles; the latter was important to successful outcomes in 64 patients undergoing aneurysm management (n = 64) and arteriovenous malformation Gamma Knife radiosurgery (n = 786). Endoscopy also had a small role but had limited cost. Beginning in 1982, a dedicated operating room CT scanner was used during both morphologic and functional stereotactic surgery (n = 1,749). After 1986, MRI was used increasingly in the management of selected functional and tumor cases (n = 337); despite great versatility for patients undergoing Gamma Knife radiosurgery, the costs were relatively high. Frameless neuronavigation (n = 263) had excellent versatility and was relatively low in cost. During the last 20 years, image guidance techniques have facilitated minimally invasive brain surgery at our institution. The relative merits of all these imaging tools depended mostly on their versatility and relative costs. Major centers currently contemplating the incorporation of image guidance into routine brain surgery need not reproduce our own learning curve.     

Leukoencephalopathy after whole‐brain radiation therapy plus radiosurgery versus radiosurgery alone for metastatic lung cancer

BACKGROUND:

As systemic therapies improve and patients live longer, concerns mount about the toxicity of whole‐brain radiation therapy (WBRT) for treatment of brain metastases. Development of delayed white matter abnormalities indicative of leukoencephalopathy have been correlated with cognitive dysfunction. This study assesses the risk of imaging‐defined leukoencephalopathy in patients whose management included WBRT in addition to stereotactic radiosurgery (SRS). This risk is compared to patients who only underwent SRS.

METHODS:

We retrospectively compared 37 patients with non–small cell lung cancer who underwent WBRT plus SRS to 31 patients who underwent only SRS. All patients survived at least 1 year after treatment. We graded the development of delayed white matter changes on magnetic resonance imaging using a scale to evaluate T₂/FLAIR (fluid attenuated image recovery) images: grade 1 = little or no white matter hyperintensity; grade 2 = limited periventricular hyperintensity; and grade 3 = diffuse white matter hyperintensity.

RESULTS:

Patients treated with WBRT and SRS had a significantly greater incidence of delayed white matter leukoencephalopathy compared to patients who underwent SRS alone (P < .001). On final imaging, 36 of 37 patients (97.3%) treated by WBRT developed leukoencephalopathy (25% with grade 2; 70.8% with grade 3). Only 1 patient treated with SRS alone developed leukoencephalopathy.

CONCLUSIONS:

Risk of leukoencephalopathy in patients treated with SRS alone for brain metastases was significantly lower than that for patients treated with WBRT plus SRS. A prospective study is necessary to correlate these findings with neurocognition and quality of life. These data supplement existing reports regarding the differential effects of WBRT and SRS on normal brain structure and function. Cancer 2013. © 2012 American Cancer Society.     

Stereotactic radiosurgery for intracranial chondrosarcoma

To assess outcomes after stereotactic radiosurgery (SRS) for chondrosarcomas of the skull base, we reviewed 22 patients with cranial base chondrosarcomas who underwent SRS between 1987 and 2009. The median patient age was 42 years (range, 15-75). The median SRS target volume was 8.0 cc (range, 0.9-28.2) and median margin dose was 15.0 Gy (range, 10.5-20). 15 patients (68 %) underwent one or more tumor resections and 3 of these patients also had fractionated radiation therapy. At a median follow-up of 75 months after SRS, seven patients died due to tumor progression. The actuarial overall survival after SRS for the entire group of chondrosarcoma patients was 95, 76, 70 and 56 % at 1, 3, 5 and 10 years, respectively. Factors associated with longer survival after SRS included patient age >40 years, a shorter interval (<6 months) between diagnosis and SRS, and either no or a single prior resection. Treated tumor control rates were 91, 72, 72 and 54 % at 1, 3, 5 and 10 years, respectively. Factors associated with longer progression-free survival after SRS included patient age >40 years and no prior RT. Symptomatic adverse radiation effects occurred in two patients (10 %). Stereotactic radiosurgery may provide a benefit to patients as either a primary or adjuvant therapy. The ability to achieve tumor control in patients with chondrosarcoma is likely to be enhanced by earlier timing of SRS after diagnosis and multimodal management, beginning with resection when feasible followed by early SRS for progressive residual tumor.