Repeat Stereotactic Radiosurgery for Locally Recurrent Brain Metastases

• Published in: World neurosurgery 2017-08, Vol.104, p.589-593
• Main Authors: Koffer, Paul, MD, Chan, Jason, MD, Rava, Paul, MD/PhD, Gorovets, Daniel, MD, Ebner, Daniel, MD, Savir, Guy, MD, Kinsella, Timothy, MD, Cielo, Deus, MD, Hepel, Jaroslaw T., MD
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Brain metastases; Brain Neoplasms - mortality; Brain Neoplasms - secondary; Brain Neoplasms - surgery; Female; Follow-Up Studies; Gamma Knife; Humans; Male; Middle Aged; Neoplasm Recurrence, Local - mortality; Neoplasm Recurrence, Local - surgery; Neurosurgery; Radiosurgery - methods; Retrospective Studies; Salvage SRS; Survival Analysis; Treatment Failure; Tumor Burden
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2017.04.103

Abstract Purpose /Objective(s): The outcomes of repeat stereotactic radiosurgery (SRS) after failure of previous SRS are not well established. We report our overall experience using SRS for the retreatment of locally recurrent brain metastases. Methods Patients with brain metastases diagnosed between 2003-2015 who underwent repeat SRS for local tumor progression following prior SRS were identified. Rates of local control, radiation necrosis, and overall survival were analyzed. Factors affecting local failure and radiation necrosis were assessed by Chi-squared test. Results 24 lesions in 22 patients underwent repeat SRS in a single fraction. Median age was 59 years. The median SRS-1 dose was 18 Gy and the median SRS-2 dose was 15.5 Gy. The median SRS-1 target volume was 2.25 cm3 and the median SRS-2 target volume was 3.30 cm3. The median follow up from SRS-2 was 8.8 months. The actuarial local control for SRS-2 was 94.1% and 61.1% at 6 and 12 months, respectively. Actuarial radiation necrosis was 9.2% and 9.2% at 6 and 12 months, respectively. Volume of tumor >4 cm3 correlated with increased risk of local failure (p=0.006) with no local failures recorded with volumes ≤4 cm3 . SRS-2 dose, cumulative SRS dose, receipt of WBRT, and use of SRS-2 as boost after surgery did not correlate with local failure or radiation necrosis. Median overall survival after SRS-2 was 8.78 months. Conclusion Repeat SRS is feasible for select patients particularly for those with tumor volume ≤4 cm3 . Further evaluation is needed to establish the most appropriate treatment doses and volumes for this approach.