Gamma knife surgery in the treatment of intracanalicular vestibular schwannomas.

OBJECTIVE: According to the literature, gamma knife surgery (GKS) is a promising method for intracanalicular vestibular schwannoma (IVS) management, providing excellent tumor growth control rates (91%-100%) and good hearing preservation rates (41%-76%), but this evidence originates primarily from a small series of patients. The aim of this study was to present the outcomes of GKS in the largest group of patients with IVS studied to date, with particular emphasis on the long-term outcomes of treatment. METHODS: The study included 136 consecutive patients with unilateral IVS, who underwent GKS in 2011-2015. Mean age of the patients was 54 ± 12.6 years. All patients were operated on with a 192-source cobalt-60 gamma knife unit. All patients had complete follow-up documentation and the mean duration of the follow-up was 52 ± 13.8 months (6-83 months). Neurological status (facial and trigeminal nerve), hearing and instability/dizziness presence were determined prior to GKS, immediately after the procedure, and during the follow-up visits. RESULTS: Tumor growth control was obtained in 124/136 (~91.2%) patients. Hearing improvement was observed in 32/136 (23.5%) patients, and there was a distinct cluster of 9 patients (6.6%) regaining serviceable hearing after GKS, whereas in 36 patients (26.5%) was stable. Four patients developed facial nerve dysfunction, including 3 periodic hemifacial spasm and 1 partial paresis, which resolved spontaneously within 12 months of GKS. None of the operated patients showed new, debilitating neurological deficits, including trigeminal sensory disturbances or hydrocephalus. CONCLUSIONS: GKS is a highly effective treatment for IVS, associated with low morbidity and good tumor growth control.

Improved cost-effectiveness of short-course radiotherapy in elderly and/or frail patients with glioblastoma.

BACKGROUND AND PURPOSE: Short-course radiotherapy (25 Gy in five fractions) was recently shown in a randomized phase III trial to be non-inferior to 40 Gy in 15 fractions in elderly and/or frail patients with glioblastoma multiforme. This study compared the cost-effectiveness of the two regimens. MATERIAL AND METHODS: The direct unit costs of imaging, radiotherapy (RT), and dexamethasone were collected from the five primary contributing countries to the trial, constituting the data of 88% of all patients. Effectiveness was measured by the restricted mean overall survival (RMOS) and progression free survival (RMPFS). The incremental cost-effectiveness ratio (ICER) was calculated. Indirect costs were also estimated for comparison. RESULTS: The median OSs for the short-course and commonly used RTs were 8.2 (95% confidence interval [CI] 6.1-10.3) and 7.7 (95% CI 5.5-9.9) months, respectively (log rank p = 0.340). Median PFSs were also not different (p = 0.686). The differences in the RMOS and the ICER, however, were +0.11 life-years and -$3062 United States dollars (USD) per life-year gained, respectively. The differences in the RMPFS and the ICER were +0.02 PFS and -$17,693 USD, respectively. CONCLUSION: The ICER of -$3062 per life-year gained and -$17,693 per PFS gained indicates that the short-course RT is less costly compared to the longer RT regimen.

International Atomic Energy Agency Randomized Phase III Study of Radiation Therapy in Elderly and/or Frail Patients With Newly Diagnosed Glioblastoma Multiforme.

PURPOSE: The optimal radiotherapy regimen for elderly and/or frail patients with newly diagnosed glioblastoma remains to be established. This study compared two radiotherapy regimens on the outcome of these patients. PATIENTS AND METHODS: Between 2010 and 2013, 98 patients (frail = age ≥ 50 years and Karnofsky performance status [KPS] of 50% to 70%; elderly and frail = age ≥ 65 years and KPS of 50% to 70%; elderly = age ≥ 65 years and KPS of 80% to 100%) were prospectively randomly assigned to two arms in a 1:1 ratio, stratified by age (< and ≥ 65 years old), KPS, and extent of surgical resection. Arm 1 received short-course radiotherapy (25 Gy in five daily fractions over 1 week), and arm 2 received commonly used radiotherapy (40 Gy in 15 daily fractions over 3 weeks). RESULTS: The short-course radiotherapy was noninferior to commonly used radiotherapy. The median overall survival time was 7.9 months (95% CI, 6.3 to 9.6 months) in arm 1 and 6.4 months (95% CI, 5.1 to 7.6 months) in arm 2 (P = .988). Median progression-free survival time was 4.2 months (95% CI, 2.5 to 5.9) in arm 1 and 4.2 months (95% CI, 2.6 to 5.7) in arm B (P = .716). With a median follow-up time of 6.3 months, the quality of life between both arms at 4 weeks after treatment and 8 weeks after treatment was not different. CONCLUSION: There were no differences in overall survival time, progression-free survival time, and quality of life between patients receiving the two radiotherapy regimens. In view of the reduced treatment time, the short 1-week radiotherapy regimen may be recommended as a treatment option for elderly and/or frail patients with newly diagnosed glioblastoma.

Prognostic value of IDH1 mutations identified with PCR-RFLP assay in glioblastoma patients.

BACKGROUND AND OBJECTIVE: It has been shown that somatic missense mutations in codon 132 of the NADP+ dependent isocitrate dehydrogenase 1 (IDH1) gene occur frequently in primary brain tumors including highly malignant glioblastoma (GBM). The aim of this study was to evaluate a PCR-restriction fragment length polymorphism (RFLP)-based method for missense mutation detection and to estimate the prognostic value of the two most frequent IDH1 codon 132 mutations, R132H and R132C, in patients with newly diagnosed GBM treated with radiation combined with temozolomide. METHODS: DNA was extracted from formalin-fixed, paraffin-embedded tissue. The PCR-RFLP method was adapted to IDH1 codon 132 mutation screening. The mutation status was determined in a group of 58 patients. RESULTS: We found R132H mutations in 14% of patients. No R132C mutation was found in this study. Median follow-up for living patients was 31 (range 17-51) months. Median progression-free survival in the group of patients with IDH1 mutation was 29 months compared with 10 months in the IDH1 wild-type group (p = 0.004; hazard ratio [HR] 3.09, 95% CI 1.25, 4.78). Median overall survival in the group with IDH1 mutation has not been reached, whereas in the group with wild-type IDH1 it was 19.5 months (p < 0.001; HR 4.76, 95% CI 1.22, 6.30). Three-year overall survival was 60% in the group with IDH1 mutation while in the wild-type IDH1 group it dropped to 29%. IDH1 mutations significantly correlated with younger age (p = 0.02). CONCLUSIONS: Our results indicate that the IDH1 R132H mutation is a powerful prognostic marker in GBM treated with chemoradiation. The PCR-RFLP method allows for a fast, inexpensive, and sensitive mutation screening.