Tratamiento con CyberKnife®: descripción de la respuesta y los efectos adversos en las metástasis cerebrales

Background: Cancer´s first cause of death are metastases. Mean survival for untreated patients is 3 months, which can extend to six or twelve months with conventional radiotherapy or chemotherapy, depending on the tumor. Stereotactic radiosurgery is a method which aims an ionizing radiation dose towards an intracranial target, guided by computarized tomography or magnetic resonance, reducing radiation on healthy brain tissue, as well as adverse effects. Its main indication is to achieve tumor control in patients with oligometastases. Methods: Retrospective, observational study, with primary and secondary sources for data, for describing results of CyberKnife® treatment. Results: Data were available for 31 patients and 62 metastases. Mean age was 54 years, 74,19 % were women. Lung cancer was the most frequent primary tumor (54,8 %); half of the cases had more than two metastases; most common location was frontal lobes (33,9 %), being 48,4 % of the tumors morphologically necrotic. There was a previous treatment in 69,4 % of the tumors. There was radionecrosis in 19,4 % of the metastases, vasogenic edema in 77,4% of them and relapses in 59,7 % of the tumors. Tumor size was reduced in 80,7 % of the metastases and tumor control was achieved in 83,9 % of them. Conclusions: CyberKnife® was able to achieve control in at least four-fifths of the treated metastases, with a relevant influence of metastases´ location in central nervous and an acceptable prevalence of radionecrosis as a complication.