Cmet-33. a Systematic Review Reveals Location Specific Toxicity Rates After Srs for Brainstem Metastases
Year: 2017
Type: conference-abstract
Abstract: Although stereotactic radiosurgery (SRS) is an effective modality in the treatment of brainstem metastases (BSM), radiation induced toxicity remains a critical concern. To better understand how severe or life-threatening toxicity is affected by the location of lesions treated in the brainstem, a systematic review of all available studies on PubMed reporting SRS treatment for BSM was performed. Twenty-seven retrospective studies investigating SRS to BSM were found. Reports included SRS delivered via Gamma Knife, Linear accelerators, and Cyber Knife. There was a total of 1992 SRS treated metastases in 1844 patients. The percentage of BSM in the pons was 62.7%, 22.6% in the midbrain, 9.4% in the midbrain, and the others were comprised of junctions among the substructures of the brainstem. The median margin dose ranged between 13–18 Gy. The number of patients receiving WBRT either before or after ranged from 6.5% - 96.4% (mean 49.8 ± 20.0%). The median tumor volume ranged from 0.1–2.8cc. Local control rate at 12 months varied from 74–100%(mean 86.5% ± 6.2%). Overall survival varied from 3.9–12 months. The rates of grade 3 or greater toxicity, based on the Common Terminology Criteria for Adverse Events varied from 0–9.5%(mean 3.6% ± 3.0%). Overall, the median time to toxicity after SRS was 3 months with 90% of toxicities occurring before 9 months. A total of 1072 cases had toxicity and location data available. The rates of toxicity associated with treatments for metastases in the pons, midbrain, and medulla regions were 3.1% (8/254), 2.8% (19/692), and 0% (0/113), respectively. A χ2 analysis demonstrated the p-value to be 0.06 and 0.07 when comparing the rate of toxicity in the medulla to that in the midbrain and pons, respectively. This raises the question if there is less toxicity in the medulla from SRS to BSM.
Source: Neuro-Oncology
Authors: Ajay Patel, Tuo Dong, Shaheryar Ansari, Aaron Cohen-Gadol, Gordon Watson, James Miller, Tim Lautenschlaeger
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2767944009