Stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) have been used as a primary treatment or adjuvant to resection in the management of intracranial meningiomas (ICMs). The aim of this analysis is to compare the safety and long-term efficacy of SRS and SRT in patients with primary or recurrent ICMs.
A systematic review of the literature comparing SRT and SRS in the same study was conducted using PubMed, the Cochrane Library, Google Scholar, and EMBASE from January 1980 to December 2018. Randomized controlled trials, case-control studies, and cohort studies (prospective and retrospective) analyzing SRS versus SRT for the treatment of ICMs in adult patients (age > 16 years) were included. Pooled and subgroup analyses were based on the fixed-effect model.
A total of 1736 patients from 12 retrospective studies were included. The treatment modality used was: 1) SRS (n = 306), including Gamma Knife surgery (n = 36), linear accelerator (n = 261), and CyberKnife (n = 9); or 2) SRT (n = 1430), including hypofractionated SRT (hFSRT, n = 268) and full-fractionated SRT (FSRT, n = 1162). The median age of patients at the time of treatment was 59 years. The median follow-up duration after treatment was 35.5 months. The median tumor volumes at the time of treatment with SRS, hFSRT, and FSRT were 2.84 cm3, 5.45 cm3, and 12.75 cm3, respectively. The radiographic tumor control at last follow-up was significantly worse in patients who underwent SRS than SRT (odds ratio [OR] 0.47, 95% confidence interval [CI] 0.27–0.82, p = 0.007) with 7% less volume of tumor shrinkage (OR 0.93, 95% CI 0.61–1.40, p = 0.72). Compared to SRS, the radiographic tumor control was better achieved by FSRT (OR 0.46, 95% CI 0.26–0.80, p = 0.006) than by hFSRT (OR 0.81, 95% CI 0.21–3.17, p = 0.76). Moreover, SRS leads to a significantly higher risk of clinical neurological worsening during follow-up (OR 2.07, 95% CI 1.06–4.06, p = 0.03) and of immediate symptomatic edema (OR 4.58, 95% CI 1.67–12.56, p = 0.003) with respect to SRT. SRT could produce a better progression-free survival at 4–10 years compared to SRS, but this was not statistically significant (p = 0.29).
SRS and SRT are both safe options in the management of ICMs. However, SRT carries a better radiographic tumor control rate and a lower incidence of posttreatment symptomatic worsening and symptomatic edema, with respect to SRS. However, further prospective studies are still needed to validate these results.