Gamma Knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part II: Differences in obliteration rates, treatment-obliteration intervals, and prognostic factors.

PURPOSE: To evaluate and compare obliteration rates (OBRs) and treatment-obliteration intervals (TOIs) for cerebral arteriovenous malformations (cAVMs) treated with Gamma Knife radiosurgery in children/adolescents and adults; and to determine factors predicting the OBR and TOI in these two populations. METHODS AND MATERIALS: This study concerned 62 children/adolescents and 193 adults observed for > or = 3 years. Fisher exact two-tailed and Wilcoxon rank-sum tests, multiple logistics, and Cox proportional hazard models were used for statistical analysis. RESULTS: The overall OBR was 85.5% in children/adolescents and 87.6% in adults (p = 0.671), but children/adolescents showed higher 36-month actuarial OBRs (69.35%) and shorter median TOIs (25.7 months) than adults (66.84% and 28.2 months; p = 0.006 and p = 0.017, respectively). In children/adolescents, lower Spetzler-Martin grades (p = 0.043) and younger age (p = 0.019) correlated significantly with OBRs, and lower Spetzler-Martin grades (p = 0.024) and noneloquent cAVM locations (p = 0.046) with TOIs. In adults, low flow through the cAVM and < 6.2-cm3 volume were associated with both OBR and TOI (p = 0.012 and p = 0.002, respectively). CONCLUSIONS: The differences in OBRs within 3 years and TOIs, although slight, seem to show that pediatric cAVMs behave differently from those in adults after Gamma Knife radiosurgery.

Gamma knife radiosurgery for cerebral arteriovenous malformations in children/adolescents and adults. Part I: Differences in epidemiologic, morphologic, and clinical characteristics, permanent complications, and bleeding in the latency period.

PURPOSE: To compare the epidemiologic, morphologic, and clinical characteristics of 92 children/adolescents (Group A) and 362 adults (Group B) with cerebral arteriovenous malformations (cAVMs) considered suitable for radiosurgery; to correlate radiosurgery-related permanent complication and post-radiosurgery bleeding rates in the 75 children/adolescents and 297 adults available for follow-up. METHODS AND MATERIALS: Radiosurgery was performed with a model C 201-source Co60 Leksell Gamma Unit (Elekta Instruments, Stockholm, Sweden). Fisher exact two-tailed, Wilcoxon rank-sum, and two-sample binomial exact tests were used for statistical analysis. RESULTS: There were significant differences between the two populations in sex (p = 0.015), clinical presentation (p = 0.001), and location (p = 0.008). The permanent complication rate was lower in younger (1.3%) than in older patients (5.4%), although the difference was not significant (p = 0.213). The postradiosurgery bleeding rate was lower in Group A (1.3%) than in Group B (2.7%) (p = 0.694), with global actuarial bleeding rates of 0.56% per year and 1.15% per year, respectively. CONCLUSIONS: The different characteristics of child/adolescent and adult cAVMs suggest that they should be considered two distinct vascular disorders. The similar rates of radiosurgery-related complications and latency period bleeding in the two populations show that gamma knife radiosurgery does not expose young patients to a higher risk of sequelae than that for older patients.

Leksell gamma knife radiosurgery for cerebral arteriovenous malformations in pediatric patients.

OBJECTS: The authors report their experience of gamma knife radiosurgery (GKR) in a large series of pediatric cerebral arteriovenous malformations (cAVMs). The advantages, risks and failures of this approach are presented and discussed. METHODS: Gamma knife radiosurgery was performed on 63 children aged < or =16 years. Haemorrhage was the clinical onset in 50 out of 63 cases. The mean pre-GK cAVM volume was 3.8 cm(3). Fifty-eight out of 63 cAVMs were Spetzler-Martin grades I-III. Most lesions (47 out of 63) were in eloquent or deep-seated brain regions. CONCLUSION: Gamma knife radiosurgery-related complications occurred in 2 out of 47 cases with an available follow-up (1 had transient and 1 permanent morbidity). No bleeding occurred during the latency period. In 39 children with >36-month follow-up, complete cAVM occlusion was angiographically documented in 31, with a 3- and 4-year actuarial obliteration rate of 72 and 77% respectively. High rates of complete obliteration and very low frequency of permanent morbidity with no bleeding during the latency period encourage widespread application of GKR in the treatment of pediatric cAVMs.

A two-stage logistic model based on the measurement of pro-inflammatory cytokines in bronchial secretions for assessing bacterial, viral, and non-infectious origin of COPD exacerbations.

UNLABELLED: Exacerbations often complicate the progressive course of chronic obstructive pulmonary disease (COPD), mainly due to infectious agents. The precise role of bacterial infections in the course and the pathogenesis of COPD has been a source of controversy for decades. Also viruses and other non-infectious causes of exacerbation play a relevant role and also contribute to persisting airway inflammation. Usually, the etiologic identification of the infective causes of COPD require considerable time and costs. The development of more rapid, reliable, and widely applicable methods to promptly define the etiology of COPD exacerbations should represent a relevant issue in devising earlier and more specific strategies for their effective therapeutic control. AIM: Of the study was to assess the predictive role of some pro-inflammatory cytokines measured in spontaneous bronchial secretions in discriminating the main infectious causes of COPD exacerbations. METHODS: 124 subjects with moderate COPD (51-79 y; mean basal FEV1 = 49.6% pred. +/- 4.6 sd; FEV1 reversibility +3.9% from baseline +/- 4.8 sd after salbutamol 200 mcg) were studied during acute exacerbation. Respiratory viruses were isolated from bronchial secretions in 21 cases; common bacteria (CFU > or = 10(6)/ml) in 28 cases; Pseudomonas Aeruginosa (Ps.Ae.; CFU > or = 10(6)/ml) in 20 cases. The cytokines IL1beta, IL8, and TNFalpha (pg/ml; Immulite; Diagnostic Product Corp, Los Angeles, CA, USA), and neutrophils (% total count) were measured in bronchial secretions of all patients. STATISTICS: A two-stage logistic model was chosen for discriminating the different causes of COPD exacerbations (such as: non-infectious, or viral, bacterial, or due to Ps.Ae.). RESULTS: At the first decisional step, the two-stage logistic model proved that TNFalpha levels in bronchial secretions recognise clearly patients belonging to the Ps.Ae. group from those of all other groups (Area under ROC curve = 0.96; 95% CI = 0.91-0.99), and that, at the second decisional step, IL8 + IL10 levels discriminate patients with bacterial causes (such as all bacteria) from the non-infected ones and from those with a viral cause of exacerbation (Area under ROC curve = 0.87; 95% CI = 0.77-0.94). Neutrophil percent count did not support any contribution in discriminating the different subgroups of COPD subjects. CONCLUSIONS: When exacerbated, COPD subjects express different patterns of pro-inflammatory mediators in bronchial secretions, which appear modulated according to the etiological cause of the exacerbation. In particular, TNFalpha concentration per se enables recognition of COPD exacerbations due to Ps.Ae., while IL8 + IL1beta levels prove helpful in discriminating those to common bacteria from those to viral agents and to non-infectious causes. When present data are further confirmed, the use of a decisional rule based on cytokine measurements might be regarded as a helpful predictive tool. As measures of pro-inflammatory cytokines are low-cost, simple, and faster to perform, they could support rapid clinical decision making at the bedside regarding therapeutic strategy for COPD exacerbations, in particular when they are needed for severe COPD patients.