Hemangiopericytoma/Solitary Fibrous Tumor in the central nervous system. Experience with surgery and radiotherapy as a complementary treatment: A 10-year analysis of a heterogeneous series in a single tertiary center / Hemangiopericitoma/tumor fibroso solitario en el sistema nervioso central. Experiencia con Cirugía y Radioterapia como tratamiento complementario: un análisis de 10 años sobre una serie heterogénea en un centro terciario

Hemangiopericytoma and Solitary Fibrous Tumor are tumors with low incidence. They have a tendency to recur locally and to metastasize. The WHO integrated both tumors into a new entity but one of the pending issues is to demonstrate the effectiveness of surgery plus complementary radiotherapy (RT) and standardize the use of it. We reviewed the data from 10 years. We assessed pathologic and radiologic characteristics. The operation records were evaluated to determine the features and extent of tumor resection. We compared the outcomes in patients using or not RT. The mean follow-up was 74.8 months, with a range of 12 and 210 months. The population included 3 males (30%) and 7 females (70%). The most common location was brain convexity (30%), the remaining were cervical and lumbar spine, sacrum, intraventricular, torcular, sphenoid ridge and intraorbital. Postoperative external beam radiotherapy was delivered in 7 patients (70%), the criteria were a partial resection or WHO II and III histological grades.2 patients developed local recurrences at 12 and 19 months after initial surgery.1 patient underwent 2 surgeries, and the other, 4 surgeries. The mean recurrence free survival rate was 15.5 months. Distant metastases were found in 4 PATIENTS: 3 of the 10 patients died. Five-year overall survival rate was 66% and mean overall survival was 76 months. A safe and complete resection in the first surgery is the most important prognostic factor.complementary RT can be helpful, even in cases of complete resection in WHO low-grade

El hemangiopericitoma y el tumor fibroso solitario son enfermedades del sistema nervioso central (SNC) con una incidencia baja. Estos tumores también pueden tener algunas características como una tendencia a recurrir localmente y hacer metástasis. La OMS, en su última clasificación de tumores del SNC, integró ambos tumores en una nueva entidad: tumor fibroso solitario/hemangiopericitoma (SFT/HPC), pero uno de los problemas actuales pendientes es demostrar la efectividad de la cirugía y la radioterapia (RT) complementaria, y estandarizar el uso de la misma. Revisamos todos los datos clínicos de nuestro hospital en un período de 10 años, y encontramos 10 pacientes con SFT/HPC. Se evaluaron los tamaños de los tumores, las ubicaciones y las características radiológicas. Los registros quirúrgicos de cada paciente se evaluaron para determinar las características macroscópicas y el alcance de la resección del tumor (EOR). También comparamos los resultados en los pacientes que utilizan o no RT como tratamiento complementario. El seguimiento medio fue de 74,8 meses, con un rango de 12 y 210 meses. La población incluía 3 varones (30%) y 7 mujeres (70%). La localización más frecuente fue la convexidad cerebral (30%). Las distribuciones de las localizaciones restantes del tumor fueron columna cervical y lumbar, sacro, intraventricular, torcular, ala esfenoidal e intraorbitario. La radioterapia postoperatoria (EBRT) se administró en 7 pacientes (70%), los criterios para tratarlos fueron una resección parcial o un grado histológico de la OMS II y III. Dos pacientes desarrollaron recidivas locales a los 12 y 19 meses después de la cirugía inicial. Un paciente se sometió a 2 cirugías, y el otro a 4 cirugías. La tasa media de supervivencia libre de recidiva (RFS) fue de 15,5 meses. Se encontraron metástasis a distancia en 4 pacientes durante el período de seguimiento. Tres de los 10 pacientes fallecieron durante el período de seguimiento. La tasa de supervivencia general a 5 años fue del 66%, y la supervivencia media global fue de 76 meses. Una resección segura y completa en la primera cirugía es el factor pronóstico más importante. Consideramos que la RT complementaria puede ser útil, incluso en casos de resección completa en SFT/HPC de bajo grado. Sería interesante definir previamente la diferenciación entre el SFT/HPC y los meningiomas para las estrategias de tratamiento

Hemangiopericytoma/Solitary Fibrous Tumor in the central nervous system. Experience with surgery and radiotherapy as a complementary treatment: A 10-year analysis of a heterogeneous series in a single tertiary center.

Hemangiopericytoma and Solitary Fibrous Tumor are tumors with low incidence. They have a tendency to recur locally and to metastasize. The WHO integrated both tumors into a new entity but one of the pending issues is to demonstrate the effectiveness of surgery plus complementary radiotherapy (RT) and standardize the use of it. We reviewed the data from 10 years. We assessed pathologic and radiologic characteristics. The operation records were evaluated to determine the features and extent of tumor resection. We compared the outcomes in patients using or not RT. The mean follow-up was 74.8 months, with a range of 12 and 210 months. The population included 3 males (30%) and 7 females (70%). The most common location was brain convexity (30%), the remaining were cervical and lumbar spine, sacrum, intraventricular, torcular, sphenoid ridge and intraorbital. Postoperative external beam radiotherapy was delivered in 7 patients (70%), the criteria were a partial resection or WHO II and III histological grades. 2 patients developed local recurrences at 12 and 19 months after initial surgery. 1 patient underwent 2 surgeries, and the other, 4 surgeries. The mean recurrence free survival rate was 15.5 months. Distant metastases were found in 4 patients. 3 of the 10 patients died. Five-year overall survival rate was 66% and mean overall survival was 76 months. A safe and complete resection in the first surgery is the most important prognostic factor. Complementary RT can be helpful, even in cases of complete resection in WHO low-grade.

A1 asynchrony, a potential risk factor for the rupture of anterior communicating artery aneurysms: A computational fluid dynamics study / Asincronía de A1, un factor de riesgo potencial para la rotura de aneurismas de la arteria comunicante anterior: un estudio de dinámica de fluidos computacional

Introduction and objectives: The anterior communicating complex is one the most common locations for aneurysm development. It receives blood from both carotid circulations and the effect of synchrony on the arrival of blood flow has not been previously studied. The objective of this study was to compare the asynchrony conditions of the A1 pulse and its effects on the haemodynamic conditions of anterior communicating artery (ACoA) aneurysms. Materials and methods: From 2008 to 2017, 54 anterior communicating artery aneurysms treated at our centre were included in the study. Computational fluid dynamics (CFD) techniques were employed and simulations consisted of complete conditions of synchrony and introducing a delay of 0.2s in the non-dominant A1 artery. Time-averaged wall shear stress (TAWSS), low shear area (LSA), A1 diameter and ACoA angles were measured. Results: The difference in the LSA in conditions of synchrony and asynchrony resulted in a broad range of positive and negative values. The symmetry index (p=0.04) and A1/A2 angle on the dominant artery (p=0.04) were associated with changes in LSA. Conclusions: In asynchrony, LSA increased in the absence of A1 asymmetry and low A1/A2 angles, potentially increasing the risk of aneurysm rupture in this location

Introducción y objetivos: El complejo comunicante anterior es una de las localizaciones más frecuentes para el desarrollo de aneurismas; recibe sangre de ambas circulaciones carotídeas y el efecto de la sincronía en la llegada de sangre no ha sido estudiado previamente. El objetivo de este estudio es comparar las condiciones de asincronía del pulso de A1 y sus efectos en las condiciones hemodinámicas de los aneurismas de la arteria comunicante anterior (ACoA). Materiales y métodos: Desde 2008 hasta 2017, 54 aneurismas de la ACoA tratados en nuestro centro se incluyeron en el estudio. Se emplearon técnicas de dinámica de fluidos computacional y las simulaciones consistieron en condiciones de completa sincronía y en la introducción de un retraso de 0,2s en la arteria A1 no dominante. Se realizaron mediciones del TAWSS, área de bajo cizallamiento (LSA), diámetros de A1 y ángulos de la AcoA. Resultados: La diferencia producida en el LSA en condiciones de sincronía y asincronía resultó en un amplio rango de valores positivos y negativos. El índice de simetría (p=0,04) y el ángulo A1/A2 en la arteria dominante (p=0,04) se relacionan con los cambios en el LSA. Conclusiones: En asincronía, el LSA se incrementó en ausencia de asimetría A1 y ángulos A1/A2 menores, incrementando potencialmente el riesgo de rotura de aneurismas en esta localización

A1 asynchrony, a potential risk factor for the rupture of anterior communicating artery aneurysms: A computational fluid dynamics study.

INTRODUCTION AND OBJECTIVES: The anterior communicating complex is one the most common locations for aneurysm development. It receives blood from both carotid circulations and the effect of synchrony on the arrival of blood flow has not been previously studied. The objective of this study was to compare the asynchrony conditions of the A1 pulse and its effects on the haemodynamic conditions of anterior communicating artery (ACoA) aneurysms. MATERIALS AND METHODS: From 2008 to 2017, 54 anterior communicating artery aneurysms treated at our centre were included in the study. Computational fluid dynamics (CFD) techniques were employed and simulations consisted of complete conditions of synchrony and introducing a delay of 0.2s in the non-dominant A1 artery. Time-averaged wall shear stress (TAWSS), low shear area (LSA), A1 diameter and ACoA angles were measured. RESULTS: The difference in the LSA in conditions of synchrony and asynchrony resulted in a broad range of positive and negative values. The symmetry index (p=0.04) and A1/A2 angle on the dominant artery (p=0.04) were associated with changes in LSA. CONCLUSIONS: In asynchrony, LSA increased in the absence of A1 asymmetry and low A1/A2 angles, potentially increasing the risk of aneurysm rupture in this location.

Hemodynamic Changes in the Treatment of Multiple Intracranial Aneurysms: A Computational Fluid Dynamics Study.

BACKGROUND: Intracranial aneurysm rupture is associated with a high mortality and disability despite modern medical care. Multiple aneurysms occur in nearly 16% of patients, and imaging studies of naturally occurring multiple aneurysms are valuable for computational fluid dynamics studies. In this study, we describe and analyze the hemodynamic changes produced in a distal aneurysm after the treatment of a proximal aneurysm. METHODS: Between January 2008 and December 2017, 24 cases of multiple intracranial aneurysms of the same vascular tree were treated in our center. Full carotid segmentations from digital subtraction angiography, computed tomography angiography, or magnetic resonance angiography were obtained, and transient pulsatile simulations were performed using computational fluid dynamics software. Output variables included maximum peak systole wall shear stress (WSS), minimum mid-diastolic WSS, maximum systolic pressure, low shear area, and high shear area both before and after treatment of the proximal aneurysm. RESULTS: The mean size of ruptured and unruptured aneurysms was 7.05 and 5.23 mm, respectively (P = 0.035), with respective aspect ratios of 1.22 and 2.04 (P = 0.001). Maximum peak systole WSS was lower and minimum mid-diastolic WSS was higher in unruptured aneurysms (P = 0.04 and 0.034, respectively). After treatment of the proximal aneurysm, low shear area in the distal aneurysm increased from 54.15% to 56.93% (P = 0.02). The opposite effect is noted in aneurysms with an interaneurysmal distance <10 mm. Posttreatment peak systole pressure was also increased significantly (P = 0.03). CONCLUSIONS: The hemodynamic changes in a distal aneurysm after treatment of a proximal aneurysm showed an unfavorable profile associated with an increased theoretical risk of bleeding.

Linear Accelerator Stereotactic Radiosurgery of Central Nervous System Arteriovenous Malformations: A 15-Year Analysis of Outcome-Related Factors in a Single Tertiary Center.

BACKGROUND: Linear accelerator stereotactic radiosurgery is one of the modalities available for the treatment of central nervous system arteriovenous malformations (AVMs). The aim of this study was to describe our 15-year experience with this technique in a single tertiary center and the analysis of outcome-related factors. METHODS: From 1998 to 2013, 195 patients were treated with linear accelerator-based radiosurgery; we conducted a retrospective study collecting patient- and AVM-related variables. Treatment outcomes were obliteration, posttreatment hemorrhage, symptomatic radiation-induced changes, and 3-year neurologic status. We also analyzed prognostic factors of each outcome and predictability analysis of 5 scales: Spetzler-Martin grade, Lawton-Young supplementary and Lawton combined scores, radiosurgery-based AVM score, Virginia Radiosurgery AVM Scale, and Heidelberg score. RESULTS: Overall obliteration rate was 81%. Nidus diameter and venous drainage were predictive of obliteration (P < 0.05), ruptured status and previous embolization were not related to rate of obliteration, and low-grade AVMs had higher obliteration rates. Posttreatment hemorrhage incidence was 8.72%; nidus diameter was the only predictor (P = 0.05). Symptomatic radiation-induced changes occurred in 11.79% of patients and were significantly associated with unruptured status (P < 0.05). Treatment success as a composite measure was obtained in 70.77% of patients. Receiver operating characteristic curves were presented for each scoring system and outcome measure; best area under the curve was 0.687 for Lawton combined score in the obliteration outcome. CONCLUSIONS: In the long-term, linear accelerator-based radiosurgery is a useful, valid, effective, and safe modality for treatment of brain AVMs.