[Hyperintensity on T2 MRI and size as predictors of obliteration in radiosurgically treated arteriovenous malformations]. / Hiperintensidad en secuencias T2 y tamaño como factores pronósticos de obliteración en malformaciones arteriovenosas tratadas mediante radiocirugía.

OBJECTIVE: The aim of this study was to determine which factors were statistically related to radiological and clinical outcomes following radiosurgical treatment of arteriovenous malformations (AVMs). METHODS: The data of 59 patients receiving radiosurgical treatment at our department were retrospectivelly reviewed. Different clinical and biological data, including Spetzler-Martin grade, the presentation of symptoms, radiation dose, number of isocenters and both radiological and clinical outcome, were subjected to multivariate analysis. RESULTS: AVM obliteration was achieved in 77% of patients, the majority of them occurring between 3-5 years after treatment. Ten patients (17%) showed either acute or delayed complications. Only one patient died due tor hemorrhage during the follow-up after radiosurgery. A multivariate analysis showed that, hyperintensity on T2 MRI and a nidus smaller than 3 cm were the only factors statistically related to oclusion of the AVM (p=0.03 and p=0.05, respectively). CONCLUSION: The nidus size and the development of hyperintensity on T2 MRI after the treatment were the strongest predictive factors of obliteration in our series of AVMs radiosurgically treated. Moreover, given that many AVMs showed complete obliteration between 3-5 years after treatment, we recommend to wait untill 5 years after treatment before considering a new terapeuthic approach in patients showing small residual nidus at control imaging.

Hiperintensidad en secuencias T2 y tamaño como factores pronósticos de obliteraciónen malformaciones arteriovenosas tratadas mediante radiocirugía / Hyperintensity on T2 MRI and size as predictors of obliteration in radiosurgically treated arteriovenous malformations

Objetivo. Analizar retrospectivamente los factoresimplicados en la obliteración de las malformacionesarteriovenosas (MAVs) tratadas mediante radiocirugía.Métodos. Se revisaron retrospectivamente las historiasclínicas y las pruebas de imagen de 59 pacientescon MAVs tratados consecutivamente mediante tratamientoradioquirúrgico en nuestro Servicio. Se recogenlos datos demográficos y clínicos en el momentodel diagnóstico, así como los referentes al tratamientoempleado y la evolución de dichos pacientes.Resultados. Se consiguió la obliteración en el 77%de las MAVs tratadas. La obliteración completa seobservó en los primeros tres años en sólo el 40% de loscasos, mientras que en el resto, la obliteración ocurrióentre los tres y los cinco años. Diez pacientes (17%)sufrieron complicaciones agudas o crónicas. Sólo unpaciente murió como resultado de una hemorragiaintraparenquimatosa durante el periodo de seguimiento.El análisis multivariable utilizando los diversosfactores y parámetros potencialmente relacionadoscon la obliteración mostró que sólo la hiperintensidadperilesional observada en secuencias T2 de la RM yun tamaño del nidus menor de 3 cm incrementaron demanera estadísticamente significativa la probabilidadde oclusión completa (p=0,03 y p=0,05, respectivamente).Conclusión. Nuestros resultados, son similares a losreportados en otras series. Sin embargo, se obtuvo unamenor tasa de oclusiones en las MAVs >3cm de diámetro,confirmando que el tamaño es un factor determinanteen probabilidad de cierre de las MAVs tratadas (..) (AU)

Objetive. The aim of this study was to determinewhich factors were statistically related to radiologicaland clinical outcomes following radiosurgical treatmentof arteriovenous malformations (AVMs).Methods. The data of 59 patients receiving radiosurgicaltreatment at our department were retrospectivellyreviewed. Different clinical and biological data,including Spetzler-Martin grade, the presentation ofsymptoms, radiation dose, number of isocenters andboth radiological and clinical outcome, were subjectedto multivariate analysis.Results. AVM obliteration was achieved in 77% ofpatients, the majority of them occurring between 3-5years after treatment. Ten patients (17%) showed eitheracute or delayed complications. Only one patient dieddue tor hemorrhage during the follow-up after radiosurgery.A multivariate analysis showed that, hyperintensityon T2 MRI and a nidus smaller than 3 cm werethe only factors statistically related to oclusion of theAVM (p=0,03 and p=0,05, respectively).Conclusion. The nidus size and the development ofhyperintensity on T2 MRI after the treatment were thestrongest predictive factors of obliteration in our seriesof AVMs radiosurgically treated. Moreover, given thatmany AVMs showed complete obliteration between 3-5years after treatment, we recommend to wait untill 5years after treatment before considering a new terapeuthicapproach in patients showing small residual nidusat control imaging. (AU)