Gamma Knife Radiosurgery for Treatment of Brain Metastases during the COVID-19 Outbreak.

INTRODUCTION: The WHO declared 2019 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) a public health emergency of international concern. The National and Regional Health System has been reorganized, and many oncological patients died during this period or had to interrupt their therapies. This study summarizes a single-centre experience, during the COVID-19 period in Italy, in the treatment of brain metastases with Gamma Knife stereotactic radiosurgery (GKRS). METHODS: We retrospectively analysed our series of patients with brain metastases who underwent GKRS at the Niguarda Hospital from February 24 to April 24, 2020. RESULTS: We treated 30 patients with 66 brain metastases. A total of 22 patients came from home and 8 patients were admitted to the emergency room for urgent neurological symptoms. Duration of stay was limited to 0-1 day in 17 patients. We chose to treat a cluster of 9 patients, whose greater lesion exceeded 10 cm3, with 2-stage modality GKRS to minimize tumour recurrence and radiation necrosis. CONCLUSION: Due to the COVID-19 pandemic, the whole world is at a critical crossroads about the use of health care resources. During the COVID-19 outbreak, the deferral of diagnostic and therapeutic procedures and a work backlog in every medical specialty are the natural consequences of reservation of resources for COVID-19 patients. GKRS improved symptoms and reduced the need for open surgeries, allowing many patients to continue their therapeutic path and sparing beds in ICUs. Neurosurgeons have to take into account the availability of stereotactic radiosurgery to reduce hospital stay, conciliating safety for patients and operators with the request for health care coming from the oncological patients and their families.

Adaptive Staged-Dose Gamma Knife Radiosurgery for the Treatment of Large Brain Metastases: Report of 40 Consecutive Cases and Analysis of Literature.

Background: Brain metastases are the most common brain tumors, being one of the most frequent neurological complications of systemic cancer and an important cause of morbidity and mortality. Stereotactic radiosurgery is efficacious and safe in the treatment of brain metastases, with good local control rates and low adverse effects rate. Large brain metastases present some issues in balancing local control and treatment-related toxicity. Objective: Demonstrating adaptive staged-dose Gamma Knife radiosurgery (ASD-GKRS) being a safe and effective treatment for large brain metastases. Materials and Methods: We retrospectively analyzed our series of patients treated with two-stage Gamma Knife radiosurgery for large brain metastases in [BLINDED], between February 2018 and May 2020. Results: Forty patients with large brain metastases underwent adaptive staged-dose Gamma Knife radiosurgery, with median prescription dose of 12 Gy and a median interval between stages of 30 days. At three-month follow-up, the survival rate was 75.0% with a local control rate of 100%. At six-month follow-up, the survival rate was 75.0% with a local control rate of 96.7%. The mean volume reduction was 21.81 cm3 (16.76-26.86; 95% CI). The difference between baseline volume and six-month follow-up volume was statistically significant. Conclusions: Adaptive staged-dose Gamma Knife radiosurgery is a safe, non-invasive and effective treatment for brain metastases, with a low rate of side effects. Large prospective trials are needed to strengthen data obtained about the effectiveness and safety of this technique in managing large brain metastases.

Stereotactic Radiosurgery with Gamma Knife in Recurrent Rathke's Cleft Cyst: Case Report and Literature Analysis.

Background: Rathke's cleft cyst is a benign expansive lesion of the sella turcica. If related to clinical disorders, the patient needs surgical treatment. Objective: To demonstrate the efficacy of radiosurgery in the treatment of relapse of Rathke's cleft cyst as an alternative to surgery. Methods and Material: The stereotactic radiosurgical treatment was performed at the Gamma Knife Center of the Niguarda Hospital in a patient with Rathke's cleft cyst subjected to two subsequent neurosurgical resections with early regrowth of the cyst. The cyst underwent radiosurgery with a prescription dose of 12 Gy at 50% (minimum dose 9.8, mean 17.3 and maximum 24.4). Results: Three years after stereotactic radiosurgical treatment the patient is asymptomatic and does not present disorders of the hypothalamic-pituitary axis or further visual alterations. The control MRI shows a reduction of the cyst's volume. Conclusions: Stereotactic radiosurgery resulted in a reduction of the cyst's volume and avoided further recourse to surgery.