Brain metastases are a leading cause of morbidity and mortality for patients with systemic cancer and are among the most common intracranial tumors in adults. Its incidence increases as cancer therapies improve, and patients live longer, providing new challenges to the multidisciplinary teams that manage these patients. The contemporary neurosurgical treatment of intracranial metastases has become gradually more complex as the available therapeutic options increase. For the past 50 years, whole brain radiotherapy and systemic corticosteroids have been considered as the standard of care for patients with brain metastases. However, in recent years, stereotactic radiosurgery is spotlighted as an alternative therapeutic modality for these patients because of its relatively short, convenient, and non-invasive treatment course. Stereotactic radiosurgery is a radiation therapy technique in which multiple focused radiation beams intersect over a target, which results in the delivery of highly conformal, high-dose of radiation to the target and minimal radiation to surrounding normal parenchyma. The purpose of this review is to provide an overview of stereotactic radiosurgery as a treatment modality for patients with brain metastases.
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Radiation therapy has multiple roles in the treatment of meningioma although surgery remains the primary treatment of choice. In this retrospective study, we report the results of radiation therapy for meningioma as definitive, postoperative or salvage therapies.
Seventeen patients diagnosed with meningioma were treated with radiation therapy in our institute from May 2000 to October 2009. Radiation therapies were performed as definitive therapies in 8 patients, as postoperative therapies in 5 and as salvage therapies in 4. Nine patients received stereotactic radiosurgery (SRS), 2 patients fractionated stereotactic radiotherapy (FSRT), and 5 patients 3-dimensional conformal radiotherapy (3DCRT). Radiation dose were 12 to 20 Gy for SRS, 36 Gy in 9 fractions for FSRT and 50.4 Gy in 28 fractions for 3DCRT. Follow-up imaging study of computed tomography or magnetic resonance imaging was performed at 6 to 12 months intervals and neurologic exam was performed with an interval less than 6 months.
The median follow-up duration was 38 months (range, 12 to 85 months). Tumor progression after radiation therapy developed in one patient. The reduction of tumor volume measured on follow-up images were more than 20% in 4 patients and minimal change of tumor volume less than 20% were observed in 12 patients. Peritumoral edema developed in 4 patients and disappeared without any treatment. One patient had radiation necrosis.
Our experience is consistent with the current understanding that radiotherapy is as an effective and safe treatment modality for meningiomas when the tumor cannot be resected completely or when recurred after surgery.