Radiocirurgia e radioterapia estereotática no tratamento de meningeomas sintomáticos do seio cavernoso / Radiosurgery and stereotactic radiotherapy in the treatment of symptomatic cavernous sinus meningiomas

Introdução: Radiocirurgia estereotática (RCE) e radioterapia estereotática fracionada (RCEF) são inovações modernas de procedimentos radioterápicos, de alta precisão que modelam o feixe de radiação para coincidir com o contorno da lesão, por meio de um sistema de imobilização exata do paciente ao aparelho, com definição do alvo através da fusão de imagens de RM, TC, Angiografia e PET/CT; em que pelas coordenadas de referência estereotática, determina-se que a dose de radiação de alta energia prescrita pelo médico seja depositada somente no volume-alvo, com preservação dos tecidos sadios, órgãos ou estruturas localizadas em suas adjacências. Meningeomas do seio cavernoso (MSCs) representam um problema especial porque podem evoluir comprimindo ou infiltrando estruturas neurovasculares presentes no seio cavernoso. Há evidências de que a RCE e a RCEF proporcionam controle satisfatório do crescimento dos meningeomas do seio cavernoso (MSCs) com efeitos adversos reduzidos. Objetivo: Avaliar resultados da avaliação clínica e da neuroimagem de doentes sintomáticos com MSCs tratados com RCEF ou RCE exclusivamente ou de modo adjuvante à neurocirurgia. Casuística e métodos: Estudo tipo coorte e retrospectivo sobre a avaliação de 89 doentes com MSC sintomático tratados com RCE (36%) ou RCEF (64%) entre janeiro de 1994 e março de 2009 e acompanhados até o final de 2012. Haviam sido submetidos à ressecação neurocirúrgica parcial (Simpson IV) ou à biopsia (Simpson V) previamente à radioterapia 29,2% dos doentes. A dose média de RCE foi de 14Gy, e a dose total de RCEF variou entre 50,4 e 54Gy, sendo fracionada em 1,8-2Gy/dose/dia. Resultados: O período de acompanhamento variou entre 36 e 180 meses (mediana de 73 meses). A percentagem de melhora dos sintomas neuroclínicos individuais e de melhora clínica e radiológica (p > 0,05) apresentou valores semelhantes nos doentes tratados com RCE ou RCEF, sendo respectivamente de 41,6% e 48,3%. Em 37% dos doentes, houve...

Introduction: Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRS) are modern innovations in radiotherapy procedures, precision shaping the radiation beam to match the contour of the lesion, through a system of accurate patient immobilization to the device, defining target through the fusion of MRI, CT, angiography and PET / CT, which is determined by reference to stereotactic coordinates. The radiation dose of high energy prescribed by the doctor to be delivery only in the target interest, with preservation of healthy tissues, organs or structures located in their vicinity. Cavernous sinus meningiomas (CSMs) pose a special problem because they can evolve compressing or infiltrating the neurovascular structures present of the cavernous sinus. There are evidences that SRS and FRS are efficient in the treatment of CSMs. Objectives: The evaluation of the long-term clinical results and neuroimaging findings in patients with symptomatic CSM treated with FSRT or SRS as single therapy or after a previous neurosurgical treatment. Patients and methods: Retrospective cohort study involving 89 patients with symptomatic CSMs treated with SRS (36%) or FSRS (64%) from January 1994 to March 2009, and followed until the end of 2012. Previous neurosurgical partial resection (Simpson IV) or biopsies (Simpson V) had been performed in 29.2% of the patients. The median dose of SRS was 14Gy and the total dose of FSRT ranged from 50.4 to 54Gy, fractionated in 1.8 to 2Gy/dose/day. Results: The follow-up period ranged from 36 to 180 months (median= 73months). There was improvement in the individual symptoms and in the clinical and radiological findings regardless the radiotherapeutic method in 41.6% and 48.3% of the patients treated with SRS or FSRT, respectively (p > 0,05). In 37% of the patients, at least one neurological complaint present before the treatment did not change and in 43.8% patients, the image of the tumor remained stable....

Radiocirurgia nos adenomas hipofisários / Radiosurgery for pituitary adenomas / Radiosurgery for pituitary adenomas

Os adenomas hipofisários correspondem a aproximadamente 15 por cento dos tumores intracraniais. As modalidades de tratamento incluem microcirurgia, terapia medicamentosa e radioterapia. A microcirurgia é o tratamento primário realizado nos pacientes com adenomas não-funcionantes e na maioria dos adenomas funcionantes. Dentre estes, a exceção são os prolactinomas, cujo tratamento primário é baseado no uso de agonistas dopaminérgicos. Entretanto, cerca de 30 por cento dos pacientes requerem tratamento adicional após a microcirurgia devido à recorrência ou persistência tumoral. Nesses casos, a radioterapia fracionada convencional tem sido tradicionalmente empregada. Mais recentemente, a radiocirurgia tem se estabelecido com uma alternativa terapêutica. A radiocirurgia permite que a dose prescrita seja precisamente conformada ao volume-alvo, e que se poupe os tecidos adjacentes. Portanto, os riscos de hipopituitarismo, alteração visual e vasculopatia são significativamente menores. Além disso, a latência da resposta à radiocirurgia é substancialmente menor do que na radioterapia fracionada convencional. Nesta revisão, procuramos definir a eficácia, segurança e o papel da radiocirurgia no tratamento dos adenomas hipofisários, bem como apresentar os dados preliminares de nossa instituição.

Pituitary adenomas represent nearly 15 percent of all intracanial tumors. Multimodal treatment includes microsurgery, medical management and radiotherapy. Microsurgery is the primary recommendation for nonfunctioning and most of functioning adenomas, except for prolactinomas that are usually managed with dopamine agonist drugs. However, about 30 percent of patients require additional treatment after microsurgery for recurrent or residual tumors. In these cases, fractionated radiation therapy has been the traditional treatment. More recently, radiosurgery has been established as a treatment option. Radiosurgery allows the delivery of prescribed dose with high precision strictly to the target and spares the surrounding tissues. Therefore, the risks of hypopituitarism, visual damage and vasculopathy are significantly lower. Furthermore, the latency of the radiation response after radiosurgery is substantially shorter than that of fractionated radiotherapy. The goal of this review is to define the efficacy, safety and role of radiosurgery for treatment of pituitary adenomas and to present the preliminar results of our institution.

Quality assurance program for prototype stereotactic system developed for Neptun 10 PC linac

A prototype stereotactic radiosurgery set was designed and constructed for a Neptun 10 PC linac that is currently being used at Imam Reza hospital in Mashhad. A complete quality assurance program was designed and performed for the constructed system including isocentric accuracy test, localization accuracy test, dose delivery accuracy test and leakage radiation test. Target simulator, control alignment device and plexiglass phantom which were parts of the developed hardware were used to fulfill quality assurance program. The average isocentric shift resulted from the gantry rotation and couch turning were respectively obtained to be 1.4 and 2 mm. The average localization error in the three coordinates was found to be 2.2 mm. The total treatment uncertainty due to all of the probable errors in the system was equal to 4.32 mm. The dose delivery accuracy test was carried out, the result indicated a 3-7% difference between the given and measured dose. The quality assurance tests showed consistent performance of the constructed system within the accepted limits; however, some inconsistency might exist in certain cases. The safety of SRS method is increased when the overall uncertainty is minimized and the treatment of the lesions adjacent to critical organs is avoided

Ventajas y desventajas del uso de la radiocirugía en el tratamiento de la neoplasia intraepitelial cervical - Estudio comparativo con conización fría

El estudio presenta tres años de experiencia en el uso de la radiocirugía (LEEP en el tratamiento de la neoplasia intraepitelial cervical (N.I.C) en el centro de la patología cervical y colposcopia de la empresa social del estado (E.S.E.) Metrosalud. Los resultados muestran las ventajas y desventajas del método en un reporte comparativo con conización hecha con bisturí frío. El LEEP permitió una mejor valorización reduciendo el diagnóstico principalmente en las pacientes con diagnóstico colpo-histológico de NIC II (37.5 por ciento), sin embargo se incrementó el porcentaje de compromiso de los bordes de resección (18.4 por ciento vs 4.8 por ciento), el cual disminuyó al lograr mayor experiencia con el método (5.8 por ciento). Se discute el manejo de los conos y LEEP con bordes comprometidos y la necesidad de un segundo procedimiento terapéutico ante la alta probabilidad de lesión residual (Cono frío = 66.7 por ciento y LEEP = 83.3 por ciento). Finalmente, se propone marginar la conización con bisturí frío a los procedimientos diagnósticos en que esté indicado en vista de su costo y morbilidad, y dejar de usarlo como procedimiento terapéutico reemplazándolo por la radiocirugía. En el futuro inmediato la radiocirugía permitirá también reducir el número de histerectomías por NIC