Predictors of response to Gamma Knife radiosurgery for intracranial meningiomas

Abstract

M eningioMas are the most common primary intracranial nonglial neoplasms in adults. 34 When feasible, the ideal management of meningiomas is complete resection of the tumor and associated dura mater, with the goal of minimizing further neurological morbidity for the patient. 28 However, not all meningiomas are amenable to gross-total resection (e.g., extensive involvement of skull base structures or invasion into the venous sinuses or other neurovascular structures), and alternative complementary treatment strategies are necessary. 4,27,40 abbreviatioNs ARE = adverse radiation event; CI RTOG = Radiation Therapy Oncology Group Conformity Index; RT = radiotherapy; SGR = specific growth rate; SRS = stereotactic radiosurgery; TVR = treatment volume ratio. obJect In this paper, the authors' aim was to determine short-term volumetric and diametric tumor growth and identify clinical, radiological, and dosimetric predictors of adverse radiation events (AREs) following stereotactic radiosurgery (SRS) for intracranial WHO Grade I meningiomas. methods This is a retrospective review of all WHO Grade I meningiomas that were treated with SRS (primary or adjuvant) between December 2005 and June 2012 at the University Health Network. Seventy-five patients had at least 24 months of both clinical and radiological follow-up and were, therefore, included in this study. Tumor growth was defined as any volumetric or diametric change greater than 10% per year. Any variation less than +10% was considered growth stability. Volumetric measurements were made using T1-weighted gadolinium-enhanced 3-T MRI scans and ITK-SNAP software. Tumor growth rates were calculated using the specific growth rate (SGR). Univariate statistics were used to identify predictors of post-SRS AREs. All statistical analyses were performed using IBM SPSS. results Women accounted for 69.3% of patients, and the mean treatment age was 58.6 years. Median follow-up was 36.2 months. Twenty-one (28%) patients had undergone prior resection. Two (3%) patients required salvage surgical intervention following SRS. The majority of the lesions (56%) were skull base tumors. Median tumor volume and diameter were 5.2 cm 3 and 27.5 mm, respectively. The absence of tumor growth was observed in 39 cases (52%) based on the volumetric measurements, while the absence of tumor growth was observed in 69 cases (92%) based on the diametric measurements. Twenty-six patients (34.6%) experienced new-onset AREs, including headache (17.3%), cranial neuropathy (10.6%), speech impairment (2.7%), tremors (2.7%), and ataxia (1.3%). Fourteen patients (18.7%) experienced new-onset edema, and 4 of these patients were symptomatic. A lower conformity index (1.24 vs 1.4) was significantly associated with the development of edema (p < 0.001 power > 0.8). Patients with meningiomas that had growth rates of more than 10% per year were more likely to experience long-term headaches after SRS (p = 0.022). coNclusioNs Volume-based reporting of SRS outcomes for meningiomas may be a more accurate method given the ...

Prognostic value of diffusion tensor imaging parameters for Gamma Knife radiosurgery in meningiomas

“…GKRS effectively controls the growth of meningiomas with a control rate of 85% to 99% at follow-ups of more than 3 years. 4,7,15 Our results are consistent with current data. In total, 89% (n = 23) of meningiomas did not progress after a mean control period of 2 years.…”

Gamma Knife radiosurgery for intracranial benign meningiomas: follow-up outcome in 130 patients

“…9,15,25 Some recent studies that were focused on the treatment of intracranial meningiomas with radiosurgery reported that the local tumor control rates ranged from 88% to 100%, in which 19%-74% of tumors shrank during a mean follow-up of 36-78 months. 3,7,12,21,22,[30][31][32][33][34]37,[39][40][41] In a single-center study, Hasegawa et al 12 reported an actuarial PFS rate of 92%, 86%, and 72% at 3, 5, and 10 years, respectively, in 67 patients. In a meta-analysis of SRS for skull base meningiomas, Starke et al 41 reviewed the outcome in 469 patients with large skull base meningiomas (> 8 cm) from several centers, and reported that the actuarial tumor PFS rates at 3, 5, and 10 years were 90.3%, 88.6%, and 77.2%, respectively.…”

“…30 Categorized by tumor site, the percentages were as follows: convexity meningiomas (16.7%), parafalcine and parasagittal meningiomas (17.9%), sellar and parasellar meningiomas (17.3%), petroclival meningiomas (14.7%), cerebellopontine angle (CPA) meningiomas (13.5%), tentorial meningiomas (10.2%), foramen magnum meningiomas (1.3%), sphenoidal meningiomas (6.4%), and olfactory meningiomas (1.9%). 21,22,41 There were 73 (46.8%) residual or progressive tumors with a median volume of 8.9 cm 3 (range 0.33-45.78 cm 3 ), and 83 (53.2%) initial tumors with a median volume of 2.6 cm 3 (range 0.23-21.1 cm 3 ).…”

Radiation-Induced Edema After Single-Fraction or Multifraction Stereotactic Radiosurgery for Meningioma: A Critical Review

“…Table 1 summarizes 26 published studies (all single-or multi-institutional retrospective analyses), listing the studies' meningioma sites, SRS treatment modality, endpoints analyzed, crude risks of edema, and timing of the onset of edema; more detailed information is provided in Tables E1 and E2 (available online at www.redjournal.org). In these tables, studies are grouped as follows (1) those with all non-BOS meningiomas (10)(11)(12)(13)(14)(15)(16)(17)(18), (2) those that separated out non-BOS meningiomas in the crude risks of edema (19)(20)(21)(22)(23)(24)(25)(26)(27), and (3) those did not separate out non-BOS meningiomas in the crude risks of edema (3,(28)(29)(30)(31)(32)(33)(34)(35).…”