Intra-operative electron beam radiotherapy for newly diagnosed and recurrent malignant gliomas: feasibility and long-term outcomes.

INTRODUCTION: Intra-operative electron beam radiotherapy (IOERT) is an alternative to dose escalation for the treatment of central nervous system tumors. The objective of this study was to describe the feasibility and long-term outcomes of IOERT in the treatment of primary and recurrent gliomas. MATERIALS AND METHODS: From January 1992 through December 2002, all patients treated with IOERT at the Hospital San Francisco de Asis, Madrid/Spain were retrospectively reviewed. The selection criteria included patients with superficial tumors, KPS >70 % and lesions <6 cm. Irradiation was administered in one section. The prescribed dose considered the amount of post-resection residual tumor, previous radiotherapy and the tolerance level of brain structures exposed to IOERT. RESULTS: There were 17 patients (53 %) with newly diagnosed malignant brain gliomas and 15 patients with recurrent tumors. The delivered dose varied from 8 to 20 Gy (median 12.5 Gy) for primary and from 8 to 16 Gy (median 10 Gy) for recurrent tumors. The median overall survival for the entire cohort was 13 months (14 and 10.4 months for the primary and recurrent, respectively). Three patients presented with radionecrosis, one patient with osteomyelitis at the craniotomy bone flap, one with intracerebral hemorrhage, and another patient experienced a pulmonary embolism. CONCLUSIONS: IOERT is a feasible technique and can be viewed as a tool in the treatment of newly diagnosed or recurrent brain gliomas.

Malformaciones arteriovenosas del tronco cerebral tratadas con radiocirugía con acelerador lineal. Resultados a largo plazo / No disponible

Objetivo Las malformaciones arteriovenosas (MAV) del tronco cerebral conllevan un alto riesgo de hemorragia recurrente y de morbimortalidad. Las opciones de tratamiento son limitadas y principalmente asientan sobre la radiocirugía estereotáctica. Estudiamos los resultados de nuestra serie de MAV de tronco tratadas con acelerador lineal (LINAC) con seguimiento a largo plazo. Métodos Se analizan retrospectivamente los datos clínicos y radiológicos de 41 pacientes consecutivos con MAV de tronco tratadas mediante radiocirugía con acelerador lineal de 6MV entre 1992 y 2010. Comprendían 25 lesiones en mesencéfalo, 14 en protuberancia, una en bulbo y otra bulboprotuberancial. Se analizan los resultados del tratamiento en cuanto a (..) (AU)

[Linear accelerator radiosurgery for brainstem arteriovenous malformations. Long-term results]. / Malformaciones arteriovenosas del tronco cerebral tratadas con radiocirugía con acelerador lineal. Resultados a largo plazo.

OBJECTIVE: Arteriovenous malformations (AVM) in the brainstem carry a high risk of recurrent haemorrhage, mortality and morbidity. Treatment options are limited and mainly based on stereotactic radiosurgery. We studied the results of our series of brainstem AVM treated with linear accelerator (LINAC) and with a long-term follow-up. METHODS: We retrospectively analysed the clinical and radiological data of 41 consecutive patients with brainstem AVM treated by radiosurgery with a 6MV linear accelerator between 1992 and 2010. Twenty five lesions were located in the mesencephalon, 14 in the pons, one in the medulla oblongata and one was bulbopontine. We analysed the treatment results in relation to survival, rate of radiological obliteration, rebleeding, and treatment toxicity. RESULTS: The obliteration rate confirmed by angiography/MRA was 59.5% on 38 controlled patients. The mean follow-up period was 61 months (range: 6.7-178) and the margin dose was 14Gy in most treatments. Up to 39% of patients received more than one radiosurgery procedure to achieve closure of the malformation. No statistical correlation was found with the margin dose, presence of pretreatment haemorrhage, nidus diameter or score on the Pollock-Flickinger grading system. The annual haemorrhage rate after radiosurgery was 3.2%. Three patients died from rebleeding and actuarial survival rate was 88% at 5 and 10 years after treatment. Four patients suffered new transient neurological deficits due to toxicity, and only one presented a permanent deficit (2.6%). CONCLUSIONS: Nidus obliteration in brainstem AVM must be achieved according to three main criteria: maximum obliteration rate forced by the high rate of rebleeding, minimal morbidity given its critical location, and the greatest possible accuracy. Stereotactic radiosurgery with our moderate-dose protocol, which we believe achieved these three premises, may become an elective therapeutic modality for these patients.