Radiosurgery of Glomus Tumors of Temporal Bone: a Meta-analysis.

OBJECTIVE

1. Perform a meta-analysis of the available data on the outcomes of stereotactic radiosurgery (SRS) for the treatment of temporal bone glomus tumors (GT), and 2) evaluate the collective outcomes of SRS treatment with respect to tumor control.

DATA SOURCES

A thorough literature search of the published English-language literature from 2011 to 2016 was performed in PubMed, Ovid, and Cochrane databases using the keywords ("Gamma Knife" or "CyberKnife" or "linear accelerator" or "radiosurgery") and ("glomus jugulare" or "jugular paraganglioma" or "glomus tympanicum").

STUDY SELECTION

Studies reporting outcomes of SRS for temporal bone GT were included.

DATA EXTRACTION

Of 45 articles found, 15 studies met our inclusion and exclusion criteria and were selected for qualitative and quantitative analyses totaling 511 patients.

DATA SYNTHESIS

Average margin dose, modality, isodose line, volume decrease, follow-up duration, and tumor control rate data were extracted and analyzed.

CONCLUSION

Gamma Knife was the most commonly implemented radiosurgery modality and was used in eight studies. The mean marginal dose varied between 13.2 and 20 Gy. The pooled tumor control rate was 95.4% (95% CI: 93.6-97.2%) over a median follow-up duration ranging between 27.4 and 148 months. Clinical data on outcomes of SRS for the treatment of GTs are sparse and primarily limited to single institutional analyses, with considerable variation in tumor volume and follow-up duration. This meta-analysis provides an in-depth analysis of the available data in the literature and reviews the reported outcomes. Future studies on SRS for GT should include data on tumor growth before radiation as well as follow-up periods sufficiently long to identify true tumor control.