J.C. Bustos

Intraoperative radiation therapy in malignant glioma: early clinical results.

Intraoperative radiation therapy (IORT) with high energy electron beams is a treatment modality that has been included in multimodal programs in oncology to improve local tumor control. From August 1991 to December 1993, 17 patients with primary (8) or recurrent (9) high grade malignant gliomas, anaplastic astrocytoma (4), anaplastic oligodendroglioma (6) and glioblastoma multiforme (7), underwent surgical resection and a single dose of 10-20 Gy intraoperative radiation therapy was delivered in tumor bed. Fourteen patients received either pre-operative (8) or post-operative (6) external beam radiation therapy. Primary gliomas: 18-months actuarial survival rate has been 56% (range: 1-21+ months) and the median survival time has not yet been achieved. Four patients developed tumor progression (median time to tumor progression: 9 months). Recurrent gliomas: 18-months actuarial survival rate and median survival time has been 47% and 13 months (range: 6-32+ months) respectively. The median time to tumor progression was 11 months. No IORT related mortality has been observed. IORT is an attractive, tolerable and feasible treatment modality as antitumoral intensification procedure in high grade malignant gliomas.

Stereotactic radiosurgery of the foramen magnum region and upper neck lesions: Technique modification

A modification of the stereotactic radiosurgical procedure to permit treatment of lesions in the foramen magnum and upper cervical regions is described. The modification consists of placing the frontal pins of the stereotactic head ring in the zigoma bone, with no changes in the position of the occipital pins, so the final BRW head ring is oblique to the orbito-meatal plane. In this new position there is room enough in the posterior part of the guide for the support scrubs. This is unhampered by the patients shoulders and the lesion is far enough to permit setting the axial coordinate sufficiently above the head ring plane.

IORT for CNS Tumors

High-grade malignant gliomas are the most common brain tumors of the adult life and account for about 30–45% of the primary human brain tumors. Of these, nearly 85% are glioblastoma multiforme (1).

El control de calidad en los tratamientos de radiocirugía. Recomendaciones metodológicas

Resumen La radiocirugia estereotaxica es una tecnica neuroquirurgica utilizada para el tratamiento de malformaciones arteriovenosas y de algunos tumores cerebrales. Se basa en la administracion de una dosis de radiacion, con gran exactitud y muy concentrada, en el volumen patologico. Utiliza diversos equipamientos: un sistema esterotaxico de localizacion espacial, equipos de identificacion de la lesion -TAC, RM o angiografia-; un sistema computarizado de planificacion y dosimetria, un sistema de posicionamiento del paciente y el sistema de irradiacion. Las caracteristicas del procedimiento de radiocirugia, donde el cumplimiento de una metodologia es basico, hacen conveniente la utilizacion de un protocolo de tratamiento, que a la vez sirva de control de calidad. El protocolo que se presenta ha sido utilizado en 300 casos tratados en la Unidad de Radiocirugia del Sanatorio San Francisco de Asis de Madrid. Esta dividido en 8 fases: recopilacion de datos e identificacion; colocacion de la guia estereotaxica, realizacion de TAC cerebral, angiografia cerebral (en malformaciones arteriovenosas), procesamiento e integracion de imagenes, planificacion y dosimetria, instalacion del equipamiento de radiocirugia en el acelerador lineal y tratamiento. Se destaca la necesidad de actuacion coordinada de los distintos especialistas –neurocirujanos, radioterapeutas, radiofisicos, neuroradiologos, informaticos, tecnicos operadores y de mantenimiento, ATS especializados, etc.– y de la disponibilidad de los equipos de diagnostico, planificacion y tratamiento.