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

OBJECTIVEThe authors retrospectively analyzed the follow-up data in 130 patients with intracranial benign meningiomas after Gamma Knife radiosurgery (GKRS), evaluated the tumor progression-free survival (PFS) rate and neurological function preservation rate, and determined the predictors by univariate and multivariate survival analysis.METHODSThis cohort of 130 patients with intracranial benign meningiomas underwent GKRS between May 2012 and May 2015 at the Second Hospital of Tianjin Medical University. The median age was 54.5 years (range 25-81 years), and women outnumbered men at a ratio of 4.65:1. All clinical and radiological data were obtained for analysis. No patient had undergone prior traditional radiotherapy or chemotherapy. The median tumor volume was 3.68 cm3 (range 0.23-45.78 cm3). A median margin dose of 12.0 Gy (range 10.0-16.0 Gy) was delivered to the tumor with a median isodose line of 50% (range 50%-60%).RESULTSDuring a median follow-up of 36.5 months (range 12-80 months), tumor volume regressed in 37 patients (28.5%), was unchanged in 86 patients (66.2%), and increased in 7 patients (5.4%). The actuarial tumor progression-free survival (PFS) rate was 98%, 94%, and 87% at 1, 3, and 5 years, respectively, after GKRS. Tumor recurred in 7 patients at a median follow-up of 32 months (range 12-56 months). Tumor volume ≥ 10 cm3 (p = 0.012, hazard ratio [HR] 8.25, 95% CI 1.60-42.65) and pre-GKRS Karnofsky Performance Scale score < 90 (p = 0.006, HR 9.31, 95% CI 1.88-46.22) were independent unfavorable predictors of PFS rate after GKRS. Of the 130 patients, 101 (77.7%) presented with one or more neurological symptoms or signs before GKRS. Neurological symptoms or signs improved in 40 (30.8%) patients, remained stable in 83 (63.8%), and deteriorated in 7 (5.4%) after GKRS. Two (1.5%) patients developed new cranial nerve (CN) deficit. Tumor volume ≥ 10 cm3 (p = 0.042, HR = 4.73, 95% CI 1.06-21.17) and pre-GKRS CN deficit (p = 0.045, HR = 4.35, 95% CI 0.84-22.48) were independent unfavorable predictors for improvement in neurological symptoms or signs. Six (4.6%) patients developed new or worsening peritumoral edema with a median follow-up of 4.5 months (range 2-7 months).CONCLUSIONSGKRS provided good local tumor control and high neurological function preservation in patients with intracranial benign meningiomas. Patients with tumor volume < 10 cm3, pre-GKRS Karnofsky Performance Scale score ≥ 90, and no pre-GKRS CN deficit (I-VIII) can benefit from stereotactic radiosurgery. It can be considered as the primary or adjuvant management of intracranial benign meningiomas.

A Single-Center Treatment Experience of Gamma Knife Radiosurgery for Optic Pathway Glioma.

Objectives: To determine the independent prognostic factors that will influence the local tumor control/visual acuity (VA) preservation of optic pathway glioma (OPG) after Gamma Knife radiosurgery (GKS) and to optimize the treatment strategy. Methods: A cohort of 52 consecutive OPG patients who underwent GKS in our center between August 1997 and September 2020 was studied retrospectively. Risk factors such as age at GKS, gender, tumor subtype, tumor site, tumor volume, intratumoral cyst formation, and marginal dose were selected for the univariate and multivariate analysis. COX proportional hazard models were built to determine the independent prognostic factors of local tumor control/VA preservation, and the Kaplan-Meier (K-M) curves were plotted to compare the survival rate among subgroups. Results: 52 OPG patients were included in this study, with a median age of 13.8 years (2-53 years); female outnumbered male at a ratio of 30 : 22; 7 patients (13.5%) had a history of surgical resection; 14 patients (26.9%) were categorized as neurofibromatosis type I (NFI) associated OPG and the rest as sporadic OPG; there were 6 patients (11.5%) with tumors located at hypothalamus/optic chiasm and the rest located in the orbit; the mean tumor volume was 4.36 ml (0.25-11.4 ml); 49 patients (94.2%) presented with VA impairment before GKS; 28 patients (53.8%) underwent single fraction GKS, and the rest underwent fractionated GKS (2-4 fractions); the mean marginal dose (represented with biologically effective dose, BED) was 66.6 Gy (13.3-126.0 Gy); the median follow-up time was 39 months (6-147 months); 11 patients were observed with tumor relapse, 33 with stable disease, and 8 with tumor regression; tumor relapse time varied from 30 to 76 months (mean 54 months); the 1-, 3-, and 5-year progression-free survival (PFS) rates were 100%, 92%, and 78%, respectively; 30 patients were included in the visual analysis; 7 patients were observed with VA deterioration, 19 with stable VA, and 4 with VA improvement; the 1-,3-, and 5-year VA preservation rates were 92%, 84%, and 77%, respectively. COX proportional hazard risk models showed that intratumoral cyst formation and marginal dose were the only two independent prognostic factors of local tumor control/VA preservation; fractionated GKS provided a higher VA preservation rate than single fraction GKS. Four patients were observed with conjunctive edema/conjunctive hyperemia in 1-4 weeks after GKS. Conclusions: GKS is a safe and effective treatment for OPG either as initial treatment or as salvage treatment after surgical resection, it provides good local tumor control and VA preservation, and fractionated GKS could be a preference for OPG patients with baseline VA ≥ 0.2.

Effects of combined radiosurgery and temozolomide therapy on epidermal growth factor receptor and variant III in glioblastoma multiforme.

Glioblastoma multiforme (GBM) is a highly malignant and notably aggressive primary tumour. Variant III of the epidermal growth factor receptor (EGFRvIII) is one of the most common types of variants in GBM, and serves an important role in tumour invasion, proliferation and treatment resistance. In the present study, statistical analyses were performed on data from 57 patients with GBM, and polymerase chain reaction detection was conducted on the tumour tissues from 32 of these patients. The results indicated that the EGFRvIII mutation was significantly associated with tumour malignancy. Human GBMU87-EGFRvIII cell lines were cultured and treated with radiosurgery and temozolomide individually, or with combined radiosurgery and temozolomide treatment. In vitro and in vivo experimental methods were used to detect the expression levels of Ki-67 and EGFRvIII. As verified in the present study, the EGFRvIII mutation is positively correlated with the malignancy of tumours, and combined radiosurgery and temozolomide therapy may inhibit the invasion and proliferation abilities of U87-EGFRvIII more effectively than treatment alone.