Single-Fractionated Stereotactic Radiosurgery for Intracranial Meningioma in Elderly Patients: 25-Year Experience at a Single Institution.

BACKGROUND: Stereotactic radiosurgery (SRS) has been accepted as a therapeutic option for intracranial meningiomas; however, the detailed data on outcomes in elderly patients remain unclear. OBJECTIVE: To delineate the efficacy of SRS for meningiomas in elderly patients. METHODS: The outcomes of 67 patients aged ≥65 yr who underwent SRS for benign intracranial meningioma (World Health Organization grade I) between 1990 and 2014 at our institution were retrospectively analyzed. The median age was 71 yr (range, 65-83 yr), and the mean and median follow-up were 62 and 52 mo (range, 7-195 mo), respectively. Tumor margins were irradiated with a median dose of 16 Gy, and the median tumor volume was 4.9 cm3 (range, 0.7-22.9 cm3). RESULTS: Actuarial local tumor control rates at 3, 5, and 10 yr after SRS were 92%, 86%, and 72%, respectively. Previous surgery and parasagittal/falcine location were statistically significant predictive factors for failed tumor control. Mild or moderate adverse events were noted in 9 patients. No severe adverse event was observed. A higher margin dose was significantly associated with adverse events by univariate analysis. CONCLUSION: SRS is one of the standard therapies for meningiomas in elderly patients, providing both favorable tumor control and a low risk of adverse events under minimum invasiveness.

Does Advanced Age Affect the Outcomes of Stereotactic Radiosurgery for Cerebral Arteriovenous Malformation?

BACKGROUND: Stereotactic radiosurgery (SRS) is generally considered a minimally invasive treatment modality. However, definitive evidence of the efficacy of SRS in the elderly population is still not available. METHODS: The outcomes of 561 elderly and nonelderly patients who underwent SRS for AVM at our institution between 1990 and 2013 were reviewed, analyzed, and compared. Elderly patients were defined as those age ≥60 years at the time of SRS. RESULTS: The elderly cohort comprised 55 patients; the nonelderly cohort, 506. In the elderly cohort, the median age was 65 years, and the duration of follow-up was 91 months. The actuarial obliteration rates were 47% at 3 years, 70% at 4 years, and 76% at 5 years in the elderly cohort, and 57% at 3 years, 76% at 4 years, and 83% at 5 years in the nonelderly cohort. In the elderly cohort, the hemorrhage rates during the post-SRS latent phase were 5.2%/year in patients with hemorrhagic onset and 0%/year in those with nonhemorrhagic onset, and event-free survival (EFS) was 93% at 6 years and 89% at 12 years. The obliteration rate, mortality, and EFS rate were not significantly different between the 2 cohorts, whereas the rate of perifocal edema was significantly lower (P = 0.021) in the elderly cohort. The pre-SRS and post-SRS hemorrhage rates were slightly higher in the elderly cohort, albeit without statistical significance. CONCLUSIONS: Therapeutic effects and outcomes of SRS are similar in elderly and nonelderly patients. Treatment-related neurologic deficits are rare, and longer EFS can be expected.

Contrast media-assisted in-treatment cone beam CT during single-isocentre volumetric-modulated arc therapy for multiple brain metastases: a case study.

A direct visualization technique for verifying intrafractional localization accuracy of multiple brain metastases during single-isocentre volumetric-modulated arc therapy has been proposed using contrast media-assisted in-treatment cone beam CT (CBCT). Contrast-enhanced planning CT images were acquired immediately after intravenous bolus administration of iodized contrast media at a dose of 2 ml kg-1. Out of 41 nodules detected on the images, 8 lesions were contoured as high-risk gross tumour volumes (GTVs). Prior to each treatment, CBCT imaging was performed to match the skull structures with the planning CT images. Immediately after another intravenous bolus injection of the iodized contrast media at the same dose as administered for the planning CT imaging, contrast-enhanced CBCT images were acquired during volumetric-modulated arc therapy delivery, thereby providing direct verification of time-averaged tumour position during treatment. The planning target volume contours were overlaid with the in-treatment CBCT images, thereby allowing us to directly visualize the localization accuracy of each GTV when the beam delivery was completed. It was visually confirmed that each GTV was accurately localized inside each planning target volume during beam delivery.

Long-Term Outcomes of Single-Session Stereotactic Radiosurgery for Cerebellar Arteriovenous Malformation, with a Median Follow-Up of 10 Years.

OBJECTIVE: Cerebellar arteriovenous malformation (C-AVM) is poorly tolerated because of its aggressive natural history. The aim of this study was to delineate long-term outcomes of Gamma Knife stereotactic radiosurgery (GKRS) for C-AVM. METHODS: The outcomes of 45 patients who underwent GKRS for C-AVMs at our institution were retrospectively analyzed. Event-free survival was defined as free from any neurologic deficits caused by AVMs or adverse phenomena from the treatment. RESULTS: The median age and follow-up were 41 years (range, 6-77 years) and 120 months (range, 5-291 months), respectively. The median volume and Pollock-Flickinger radiosurgical AVM score were 1.3 cm3 (range, 0.1-8.3 cm3) and 1.26 (range, 0.5-2.06), respectively. Actuarial obliteration rates were 46%, 75%, and 90% at 3, 5, and 6 years, respectively. Multivariate analysis showed that the maximal diameter ≤15 mm (P = 0.021) and margin dose >20 Gy (P = 0.0008) were significantly associated with better obliteration. Four patients experienced posttreatment hemorrhages, and annual hemorrhage rates were 1.9% and 0.30% before and after obliteration, respectively. One patient died because of hemorrhage, whereas the other 3 patients spontaneously recovered. Perifocal edema was confirmed in 8 (16%); however, no symptomatic edema was observed. Overall, neurologic deteriorations were noted in 4 patients; 3 were because of posttreatment hemorrhage, and 1 was because of pretreatment angiography. The event-free survival rates were 96%, 93%, and 93% at 4, 10, and 15 years, respectively. CONCLUSIONS: GKRS is a reasonable intervention for C-AVMs. Symptomatic complications are rare, and the long-term outcomes are favorable.

Discrete regions in the laterodorsal tegmental area of the rat regulating the urinary bladder and external urethral sphincter.

In urethane anesthetized rats, the laterodorsal tegmental area was stimulated systematically with a carbon fiber electrode to clarify regions regulating the urinary bladder and/or the external urethral sphincter. Contraction of the former was monitored by bladder pressure and that of the latter by electromyogram. Stimulation of a small area around the ventrolateral edge of the central gray in a plane at the junction of the mesencephalon and pons, where cholinergic neurons in the laterodorsal tegmental nucleus formed the largest mass, induced contraction only of the bladder. Arranged in tandem rostrocaudally with this bladder site, a very small area whose stimulation induced contraction only of the sphincter was found also at the ventrolateral edge of the central gray in a plane slightly caudal to the above. Slightly lateral and caudal to this sphincter site, there were sites the stimulation of which induced contraction of both the bladder and sphincter. It was thus shown physiologically that there were discrete sites in the laterodorsal tegmental area regulating the bladder and sphincter independently.