Cystic Formation After Stereotactic Radiosurgery of Brain Metastasis

Limited information is available on the natural history and etiology of cystic formation after stereotactic radiosurgery (SRS) for brain metastases (BM). We aimed to characterize the natural history of cyst formation after SRS of BM and analyze potential risk factors. We retrospectively reviewed 214...

Full description

Saved in:
Bibliographic Details
Published in:World neurosurgery 2018-06, Vol.114, p.e719-e728
Main Authors: Alattar, Ali A., Carroll, Kate, Hirshman, Brian R., Joshi, Rushikesh S., Sanghvi, Parag, Chen, Clark C.
Format: Article
Language:English
Subjects:
Brain metastasis
Cyst
Cystic formation
Radiosurgery
Repeat SRS
SRS
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Limited information is available on the natural history and etiology of cystic formation after stereotactic radiosurgery (SRS) for brain metastases (BM). We aimed to characterize the natural history of cyst formation after SRS of BM and analyze potential risk factors. We retrospectively reviewed 214 consecutive patients who underwent a total of 1106 SRSs for BM. Demographic, clinical, dosimetric, and magnetic resonance imaging MRI data were reviewed. Statistical analysis was accomplished using Student's t test, and univariate and multivariate logistic regression. The median patient age was 61 years (range, 19–91 years), and the median duration of follow-up was 424 days (range, 91–2934 days). Eleven cases of cyst formation (0.9% of 1106 treated lesions) were identified at SRS-treated BM sites among 9 patients (2 patients developed cysts at independent sites). The median interval between first SRS and first evidence of cyst was 218 days. Seven of the 9 patients (78%) sustained progressive cyst expansion and neurologic decline requiring steroid treatment. Four of these 7 patients (57%) experienced continued neurologic decline and needed surgical fenestration. On univariate analysis, receipt of >4 rounds of SRS was the sole variable associated with an increased risk of cyst formation (odds ratio, 16.58; P = 0.001). This association remained robust after adjusting for duration of follow-up (odds ratio, 13.59; P = 0.003). In our experience with 1106 SRS-treated cases of BM, cyst formation was a rare phenomenon. However, 1 in 3 patients who underwent >4 rounds of SRS sustained cyst formation. A high proportion (78%) of SRS-associated cysts progressively expanded and required medical or surgical treatment. •Cyst formation after stereotactic radiosurgery for brain metastases is normally rare.•With >4 rounds of radiosurgery, cysts form in 1 in 3 patients.•Most cysts form within 1 year of radiosurgery.•Once formed, cysts persist and progressively expand.•Most cysts require treatment with steroids or surgery.
ISSN:1878-8750
1878-8769
DOI:10.1016/j.wneu.2018.03.066