Single session versus hypofractionated stereotactic radiosurgery for large meningiomas (> 8 cc): a systematic review...

For larger meningiomas, higher radiation doses need to be delivered to the tumor, increasing the chances of radiation induced toxicity. Hypofractionated stereotactic radiosurgery (HSRS) imparts overall high dose in small multiple fractions, minimising this risk over single session SRS (SSRS). This meta analysis was conducted to homogenize the role of SRS for large meningiomas (> 8 cc) and run a comparative analysis between HSRS and SSRS.

Pubmed and Cochrane databases were systematically reviewed to include the relevant articles and meta analysis was performed to estimate pooled favorable clinical outcomes, tumor control and peritumoral edema (PTE) rates. Statistical tests were utilized to compare SSRS and HSRS modalities.

791 lesions underwent SSRS while 273 tumors were administered HSRS. Significantly higher percentage of Skull base tumors underwent HSRS over SSRS (84.6% vs. 76%, p = 0.003) and mean tumor size was significantly higher in the HSRS cohort (17.6 cc vs. 14.6 cc, p = 0.014). The pooled tumor control and favorable clinical outcome rates were 90% and 85% respectively, with no significant differences in HSRS and SSRS cohorts (95% vs. 90%, logit difference: 0.645, p = 0.10 and 87% vs. 85%, logit difference: 0.26, p = 0.48 respectively). Post radiosurgical PTE incidence was statistically similar for both cohorts with an overall pooled incidence of 7.9% (logit difference = 0.03, p = 0.95). Follow up period was significantly higher in patients undergoing SSRS (67 vs. 49 months, p = 0.037).

Despite having significantly larger tumor volume, HSRS could achieve similar outcomes with SSRS. However, the inadequacy of data on direct comparative studies between HSRS and SSRS warrants prospective multicenter trials with international collaboration and long term follow up for HSRS.

Not applicable.