Management of adverse radiation effects after radiosurgery

Single-session stereotactic radiosurgery for large perioptic meningiomas

OBJECTIVE

Meningiomas close to the optic pathway are commonly candidates for microsurgical decompression, more so if they are large perioptic meningiomas. However, microsurgery itself imposes risk to vision, and the larger the tumor, the more the risk and the lower the possibility of postoperative visual recovery. Fractionated stereotactic radiotherapy is usually reserved for such cases. The purpose of this study was to assess the long-term efficacy and safety of single-session stereotactic radiosurgery (SRS) for large (≥ 10 cm3) perioptic intracranial benign meningiomas.

METHODS

This retrospective study included 175 patients with large perioptic benign meningiomas (≥ 10 cm3) who were treated by single-session SRS. Perioptic meningiomas were defined as meningiomas touching, compressing, or within 3 mm of the optic pathway. The median tumor volume was 15 cm3 (range 10-57.3 cm3, IQR 8.4 cm3). The median prescription dose was 12 Gy (range 9-14 Gy, IQR 1 Gy).

RESULTS

The median follow-up period was 72 months (range 13-217 months, IQR 65 months). The tumor control rate was 92%. The progression-free survival rates at 5 and 10 years were 97% and 80%, respectively. Favorable (better/stable) visual outcome was reported in 169 patients (97%) and unfavorable (worse) outcome in 6 patients (3%). Temporary adverse radiation effects were observed in 21 patients (12%), but only 7 patients (4%) were symptomatic. Sixty-three patients had a blind/nonuseful eye according to the pretreatment visual field examination. Visual improvement was observed in the blind/nonuseful eye in 17 patients (27%), while vision remained unchanged in 46 patients (73%). Ocular nerve palsy improved in 36 patients (61%). Tumor shrinkage was not a prerequisite for cranial nerve improvement.

CONCLUSIONS

SRS provides an effective and safe treatment option for large perioptic meningiomas.

Single-Session Stereotactic Radiosurgery for Large Benign Meningiomas: Medium-to Long-Term Results

BACKGROUND

The use of stereotactic radiosurgery for the treatment of intracranial meningiomas has been established as an effective and safe treatment modality. Larger meningiomas typically are managed by surgery followed by radiosurgery. Treatment of large meningiomas (usually defined as >10 cc) by stereotactic radiosurgery has been investigated in some recent reports, either by single-session, volume-staged, or the hypofractionation technique. We sought to assess the long-term efficacy and safety of single-session stereotactic radiosurgery for large (10 cc or more) intracranial benign meningiomas.

PATIENTS AND METHODS

In this retrospective study, we included 273 patients with large benign meningiomas (≥10 cc) who were treated by single-session SRS and followed up for more than 2 years. Tumors were in a basal location in 228 patients (84%). There were 161 tumors (59%) in the perioptic location. The median tumor volume was 15.5 (10-57.3 cc [interquartile range {IQR} 12.3 cc]). The median prescription dose was 12 Gy (9-15 Gy [IQR 1 Gy]).

RESULTS

The median follow-up period was 6.1 years (2-18 years [IQR 5.5 years]). The tumor control rate was 90%. The progression-free survival at 5 and 10 years was 96% and 81%, respectively, for the whole cohort. Among 161 patients with perioptic meningiomas, favorable (better/stable) visual outcome was reported in 155 patients (96%) and unfavorable (worse) outcome in 6 patients (4%). Temporary adverse radiation effects were observed in 41 patients (15%) but only 16 (6%) were symptomatic.

CONCLUSIONS

Stereotactic radiosurgery provides an effective and safe treatment option for large meningiomas.

The management of central neurocytoma: radiosurgery

Stereotactic radiosurgery (SRS) has evolved into a mainstay in the primary and adjuvant management of most intracranial tumors. Central neurocytomas are rare, usually benign, intraventricular tumors that can be challenging to completely resect and often recur. Adjuvant therapy has been suggested for residual or recurrent tumors, especially in the setting of atypical neurocytomas. The limited data available suggest that SRS is a highly effective treatment approach for primary and adjuvant therapy, with tumor control rates of 80% to 90%. Due to its highly conformal and selective nature, SRS avoids the inconvenience and delayed toxicity of conventional radiation therapy.

Long-Term Survival and Improved Quality of Life following Multiple Repeat Gamma Knife Radiosurgeries for Recurrent Glioblastoma Multiforme: A Case Report and Review of the Literature

The management of glioblastoma multiforme (GBM) is in most cases complex and must be specifically tailored to the needs of the patient with the goals of extended survival and improved quality of life. Despite advancements in therapy, treatment outcomes remain almost universally poor. Salvage treatment options for the recurrence of the disease is an area of intense study. The following case highlights the utility of Gamma Knife Radiosurgery (GKRS) as a salvage treatment. In this clinical situation, three sequential GKRS treatments led to prolonged survival (beyond four years after diagnosis) and improved quality of life in a patient who was unable to receive further chemotherapy regimens and was unwilling to undergo further aggressive resection. To date, there have been few reports of three or more sequential GKRS treatment sessions utilized as salvage therapy for recurrent GBM in patients who can no longer tolerate chemotherapy. This report provides evidence that aggressive local treatment with GKRS at the time of recurrence may be appropriate, depending on a patient's individual clinical situation, and can lead to prolonged survival and improved quality of life.

A review of the clinical outcomes for patients diagnosed with brainstem metastasis and treated with stereotactic radiosurgery

Only 3%-5% of all brain metastases are located in the brainstem. We present a comprehensive review of the clinical outcomes from modern studies that treated patients with brainstem metastasis using either a Gamma Knife or a linear accelerator-based stereotactic radiosurgery. The median survival time of patients was compared to better understand what clinical or treatment factors are predictive of improved survival. This information can then be utilized to optimize patient care. The data suggests that higher prescribed marginal dose and the associated greater local control of brainstem lesions are associated with longer patient survival. Further research is necessary to better describe the most effective dose for individual brainstem lesions and to tailor optimum therapy to specific patient subgroups.