Baseline circulating tumour DNA and interim PET predict response in relapsed/refractory classical Hodgkin lymphoma.

Reliable biomarkers for early identification of treatment failure in relapsed/refractory (r/r) classical Hodgkin lymphoma (cHL) are lacking. Circulating tumour DNA (ctDNA) profiling has emerged as a powerful predictive and prognostic tool in several haemopoietic and non-haemopoietic malignancies and may guide rational treatment choices in r/r cHL. To assess the predictive and prognostic value of ctDNA, we performed a retrospective analysis on 55 r/r cHL patients treated with the bendamustine, gemcitabine and vinorelbine (BEGEV) regimen and additionally evaluated the potential utility of integrating ctDNA with interim [18 F]-FDG positron emission tomography (iPET). Baseline ctDNA genotyping in r/r cHL mirrored gene mutations and pathways involved in newly diagnosed cHL. We found that baseline ctDNA quantification and serial ctDNA monitoring have prognostic value in r/r cHL receiving salvage chemotherapy. Lastly, integrating ctDNA quantification with iPET evaluation may improve the early identification of patients at high risk of failing standard salvage therapy, who may benefit from an early switch to immunotherapeutic agents. Collectively, our results support the implementation of non-invasive methods to detect minimal residual disease in recurrent cHL and justify its prospective evaluation in appropriately designed clinical trials.

Genetic and phenotypic attributes of splenic marginal zone lymphoma.

Splenic marginal zone B-cell lymphoma (SMZL) is a heterogeneous clinico-biological entity. The clinical course is variable, multiple genes are mutated with no unifying mechanism, and essential regulatory pathways and surrounding microenvironments are diverse. We sought to clarify the heterogeneity of SMZL by resolving different subgroups and their underlying genomic abnormalities, pathway signatures, and microenvironment compositions to uncover biomarkers and therapeutic vulnerabilities. We studied 303 SMZL spleen samples collected through the IELSG46 multicenter international study (NCT02945319) by using a multiplatform approach. We carried out genetic and phenotypic analyses, defined self-organized signatures, validated the findings in independent primary tumor metadata and in genetically modified mouse models, and determined correlations with outcome data. We identified 2 prominent genetic clusters in SMZL, termed NNK (58% of cases, harboring NF-κB, NOTCH, and KLF2 modules) and DMT (32% of cases, with DNA-damage response, MAPK, and TLR modules). Genetic aberrations in multiple genes as well as cytogenetic and immunogenetic features distinguished NNK- from DMT-SMZLs. These genetic clusters not only have distinct underpinning biology, as judged by differences in gene-expression signatures, but also different outcomes, with inferior survival in NNK-SMZLs. Digital cytometry and in situ profiling segregated 2 basic types of SMZL immune microenvironments termed immune-suppressive SMZL (50% of cases, associated with inflammatory cells and immune checkpoint activation) and immune-silent SMZL (50% of cases, associated with an immune-excluded phenotype) with distinct mutational and clinical connotations. In summary, we propose a nosology of SMZL that can implement its classification and also aid in the development of rationally targeted treatments.

XPO1 mutations identify early-stage CLL characterized by shorter time to first treatment and enhanced BCR signalling.

Here we evaluated the epigenomic and transcriptomic profile of XPO1 mutant chronic lymphocytic leukaemia (CLL) and their clinical phenotype. By ATAC-seq, chromatin regions that were more accessible in XPO1 mutated CLL were enriched of binding sites for transcription factors regulated by pathways emanating from the B-cell receptor (BCR), including NF-κB signalling, p38-JNK and RAS-RAF-MEK-ERK. XPO1 mutant CLL, consistent with the chromatin accessibility changes, were enriched with transcriptomic features associated with BCR and cytokine signalling. By combining epigenomic and transcriptomic data, MIR155HG, the host gene of miR-155, and MYB, the transcription factor that positively regulates MIR155HG, were upregulated by RNA-seq and their promoters were more accessible by ATAC-seq. To evaluate the clinical impact of XPO1 mutations, we investigated a total of 957 early-stage CLL subdivided into 3 independent cohorts (N = 276, N = 286 and N = 395). Next-generation sequencing analysis identified XPO1 mutations as a novel predictor of shorter time to first treatment (TTFT) in all cohorts. Notably, XPO1 mutations maintained their prognostic value independent of the immunoglobulin heavy chain variable status and early-stage prognostic models. These data suggest that XPO1 mutations, conceivably through increased miR-155 levels, may enhance BCR signalling leading to higher proliferation and shorter TTFT in early-stage CLL.

International prognostic score for asymptomatic early-stage chronic lymphocytic leukemia.

Most patients with chronic lymphocytic leukemia (CLL) are diagnosed with early-stage disease and managed with active surveillance. The individual course of patients with early-stage CLL is heterogeneous, and their probability of needing treatment is hardly anticipated at diagnosis. We aimed at developing an international prognostic score to predict time to first treatment (TTFT) in patients with CLL with early, asymptomatic disease (International Prognostic Score for Early-stage CLL [IPS-E]). Individual patient data from 11 international cohorts of patients with early-stage CLL (n = 4933) were analyzed to build and validate the prognostic score. Three covariates were consistently and independently correlated with TTFT: unmutated immunoglobulin heavy variable gene (IGHV), absolute lymphocyte count higher than 15 × 109/L, and presence of palpable lymph nodes. The IPS-E was the sum of the covariates (1 point each), and separated low-risk (score 0), intermediate-risk (score 1), and high-risk (score 2-3) patients showing a distinct TTFT. The score accuracy was validated in 9 cohorts staged by the Binet system and 1 cohort staged by the Rai system. The C-index was 0.74 in the training series and 0.70 in the aggregate of validation series. By meta-analysis of the training and validation cohorts, the 5-year cumulative risk for treatment start was 8.4%, 28.4%, and 61.2% among low-risk, intermediate-risk, and high-risk patients, respectively. The IPS-E is a simple and robust prognostic model that predicts the likelihood of treatment requirement in patients with early-stage CLL. The IPS-E can be useful in clinical management and in the design of early intervention clinical trials.

Multiregional sequencing and circulating tumour DNA analysis provide complementary approaches for comprehensive disease profiling of small lymphocytic lymphoma.

We aimed at molecularly dissecting the anatomical heterogeneity of small lymphocytic lymphoma (SLL), by analysing a cohort of 12 patients for whom paired DNA from a lymph node biopsy and circulating cells, as well as plasma-circulating tumour DNA (ctDNA) was available. Notably, the analyses of the lymph node biopsy and of circulating cells complement each other since a fraction of mutations (20·4% and 36·4%, respectively) are unique to each compartment. Plasma ctDNA identified two additional unique mutations. Consistently, the different synchronous sources of tumour DNA complement each other in informing on driver gene mutations in SLL harbouring potential prognostic and/or predictive value.

Circulating tumor DNA reveals genetics, clonal evolution, and residual disease in classical Hodgkin lymphoma.

The rarity of neoplastic cells in the biopsy imposes major technical hurdles that have so far limited genomic studies in classical Hodgkin lymphoma (cHL). By using a highly sensitive and robust deep next-generation sequencing approach for circulating tumor DNA (ctDNA), we aimed to identify the genetics of cHL in different clinical phases, as well as its modifications on treatment. The analysis was based on specimens collected from 80 newly diagnosed and 32 refractory patients with cHL, including longitudinal samples collected under ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) chemotherapy and longitudinal samples from relapsing patients treated with chemotherapy and immunotherapy. ctDNA mirrored Hodgkin and Reed-Sternberg cell genetics, thus establishing ctDNA as an easily accessible source of tumor DNA for cHL genotyping. By identifying STAT6 as the most frequently mutated gene in ∼40% of cases, we refined the current knowledge of cHL genetics. Longitudinal ctDNA profiling identified treatment-dependent patterns of clonal evolution in patients relapsing after chemotherapy and patients maintained in partial remission under immunotherapy. By measuring ctDNA changes during therapy, we propose ctDNA as a radiation-free tool to track residual disease that may integrate positron emission tomography imaging for the early identification of chemorefractory patients with cHL. Collectively, our results provide the proof of concept that ctDNA may serve as a novel precision medicine biomarker in cHL.

A laboratory-based scoring system predicts early treatment in Rai 0 chronic lymphocytic leukemia.

We present a laboratory-based prognostic calculator (designated CRO score) to risk stratify treatment-free survival in early stage (Rai 0) chronic lymphocytic leukemia (CLL) developed using a training-validation model in a series of 1,879 cases from Italy, the United Kingdom and the United States. By means of regression analysis, we identified five prognostic variables with weighting as follows: deletion of the short arm of chromosome 17 and unmutated immunoglobulin heavy chain gene status, 2 points; deletion of the long arm of chromosome 11, trisomy of chromosome 12, and white blood cell count >32.0x103/microliter, 1 point. Low-, intermediate- and high-risk categories were established by recursive partitioning in a training cohort of 478 cases, and then validated in four independent cohorts of 144 / 395 / 540 / 322 cases, as well as in the composite validation cohort. Concordance indices were 0.75 in the training cohort and ranged from 0.63 to 0.74 in the four validation cohorts (0.69 in the composite validation cohort). These findings advocate potential application of our novel prognostic calculator to better stratify early-stage CLL, and aid case selection in risk-adapted treatment for early disease. Furthermore, they support immunocytogenetic analysis in Rai 0 CLL being performed at the time of diagnosis to aid prognosis and treatment, particularly in today's chemofree era.

Biological and clinical implications of BIRC3 mutations in chronic lymphocytic leukemia.

BIRC3 is a recurrently mutated gene in chronic lymphocytic leukemia (CLL) but the functional implications of BIRC3 mutations are largely unexplored. Furthermore, little is known about the prognostic impact of BIRC3 mutations in CLL cohorts homogeneously treated with first-line fludarabine, cyclophosphamide, and rituximab (FCR). By immunoblotting analysis, we showed that the non-canonical nuclear factor-κB pathway is active in BIRC3-mutated cell lines and in primary CLL samples, as documented by the stabilization of MAP3K14 and by the nuclear localization of p52. In addition, BIRC3-mutated primary CLL cells are less sensitive to flu-darabine. In order to confirm in patients that BIRC3 mutations confer resistance to fludarabine-based chemoimmunotherapy, a retrospective multicenter cohort of 287 untreated patients receiving first-line FCR was analyzed by targeted next-generation sequencing of 24 recurrently mutated genes in CLL. By univariate analysis adjusted for multiple comparisons BIRC3 mutations identify a poor prognostic subgroup of patients in whom FCR treatment fails (median progression-free survival: 2.2 years, P<0.001) similar to cases harboring TP53 mutations (median progression-free survival: 2.6 years, P<0.0001). BIRC3 mutations maintained an independent association with an increased risk of progression with a hazard ratio of 2.8 (95% confidence interval 1.4-5.6, P=0.004) in multivariate analysis adjusted for TP53 mutation, 17p deletion and IGHV mutation status. If validated, BIRC3 mutations may be used as a new molecular predictor to select high-risk patients for novel frontline therapeutic approaches.

Significant improvement of glycemic control in diabetic patients with HCV infection responding to direct-acting antiviral agents.

Many studies showed insulin resistance amelioration in HCV-patients achieving Sustained Virologic Response (SVR) but results on glycemic control in diabetic patients are unclear. This study aimed to assess fasting glucose (FG) and glycated hemoglobin (HbA1c) values before and after therapy with direct-acting antivirals (DAAs) in HCV-patients with type 2 diabetes mellitus (T2DM). Of the 122 consecutively recruited patients with chronic hepatitis C and T2DM, 110 patients were treated with DAAs and 12 remained untreated. Clinical, biochemical, virological, and metabolic features were collected both at baseline and at 12 weeks after the end of therapy (EOT) or after a comparable period of time in untreated patients. A total of 101 patients obtained a SVR (Group 1), while nine were relapsers. Group 2 (21 patients) was composed by the nine relapsers and the 12 untreated patients. A significant reduction of mean FG (134.3 ± 41.32 mg/dL vs 152.4 ± 56.40 mg/dL, P = 0.002) and HbA1c values (46.51 ± 16.15 mmoL/moL vs 52.15 ± 15.43 mmoL/moL, P < 0.001) was found in Group 1 but not in Group 2 (140.6 ± 47.87 mg/dL vs. 145.31 ± 30.18 mg/dL, P = 0.707, and 55.31 ± 20.58 mmoL/moL vs. 53.38 ± 9.49 mmoL/moL, P = 0.780). In Group 1, 20.7% of patients could reduce or suspend their antidiabetic therapy compared to none in Group 2 (P = 0.03), despite the significant weight increase observed in Group 1. SVR induced a significant amelioration of glycemic control in diabetic HCV-patients, despite a significant weight increase; larger prospective studies are needed to verify whether these results are maintained over the long-term.

Negativization of viremia prior to liver transplant reduces early allograft dysfunction in hepatitis C-positive recipients.

Although early allograft dysfunction (EAD) negatively impacts survival from the first months following liver transplantation (LT), direct-acting antiviral agents (DAAs) have revolutionized hepatitis C virus (HCV) therapy. We investigated the EAD definition best predicting 90-day graft loss and identified EAD risk factors in HCV-positive recipients. From November 2002 to June 2016, 603 HCV-positive patients (hepatocellular carcinoma, 53.4%) underwent a first LT with HCV-negative donors. The median recipient Model for End-Stage Liver Disease (MELD) score was 15, and the median donor age was 63 years. At LT, 77 (12.8%) patients were HCV RNA negative; negativization was achieved and maintained by pre-LT antiviral therapy (61 patients) or pre-LT plus a pre-emptive post-LT course (16 patients); 60 (77.9%) patients received DAAs and 17 (22.1%) interferon. We compared 3 different EAD definitions: (1) bilirubin ≥ 10 mg/dL or international normalized ratio ≥ 1.6 on day 7 after LT or aspartate aminotransferase or alanine aminotransferase > 2000 IU/L within 7 days of LT; (2) bilirubin > 10 mg/dL on days 2-7 after LT; and (3) MELD ≥ 19 on day 5 after LT. EAD defined by MELD ≥ 19 on day 5 after LT had the lowest negative (0.1) and the highest positive (1.9) likelihood ratio to predict 90-day graft loss. At 90 days after LT, 9.2% of recipients with EAD lost their graft as opposed to 0.7% of those without EAD (P < 0.001). At multivariate analysis, considering variables available at LT, MELD at LT of >25 (OR = 7.4) or 15-25 (OR = 3.2), graft macrovesicular steatosis ≥ 30% (OR = 6.7), HCV RNA positive at LT (OR = 2.7), donor age > 70 years (OR = 2.0), earlier LT era (OR = 1.8), and cold ischemia time ≥ 8 hours (OR = 1.8) were significant risk factors for EAD. In conclusion, in HCV-positive patients, MELD ≥ 19 on day 5 after LT best predicts 90-day graft loss. Preventing graft infection by pre-/peri-LT antiviral therapy reduces EAD incidence and could be most beneficial in high-MELD patients and recipients of suboptimal grafts. Liver Transplantation 23 915-924 2017 AASLD.

Molecular prediction of durable remission after first-line fludarabine-cyclophosphamide-rituximab in chronic lymphocytic leukemia.

Fludarabine, cyclophosphamide, and rituximab (FCR) has represented a significant treatment advancement in chronic lymphocytic leukemia (CLL). In the new scenario of targeted agents, there is an increasing interest in identifying patients who gain the maximum benefit from FCR. In this observational multicenter retrospective analysis of 404 CLL patients receiving frontline FCR, the combination of three biomarkers that are widely tested before treatment (IGHV mutation status, 11q deletion and 17p deletion; available in 80% of the study cohort) allowed to identify a very low-risk category of patients carrying mutated IGHV genes but neither 11q or 17p deletion that accounted for 28% of all cases. The majority of very low-risk patients (71%) remained free of progression after treatment and their hazard of relapse decreased after 4 years from FCR. The life expectancy of very low-risk patients (91% at 5 years) was superimposable to that observed in the matched normal general population, indicating that neither the disease nor complications of its treatment affected survival in this favorable CLL group. These findings need a prospective validation and may be helpful for the design of clinical trials aimed at comparing FCR to new targeted treatments of CLL, and, possibly, for optimized disease management.

Early reappearance of intraclonal proliferative subpopulations in ibrutinib-resistant chronic lymphocytic leukemia.

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib represents an effective strategy for treatment of chronic lymphocytic leukemia (CLL), nevertheless about 30% of patients eventually undergo disease progression. Here we investigated by flow cytometry the long-term modulation of the CLL CXCR4dim/CD5bright proliferative fraction (PF), its correlation with therapeutic outcome and emergence of ibrutinib resistance. By longitudinal tracking, the PF, initially suppressed by ibrutinib, reappeared upon early disease progression, without association with lymphocyte count or serum beta-2-microglobulin. Somatic mutations of BTK/PLCG2, detected in 57% of progressing cases, were significantly enriched in PF with a 3-fold greater allele frequency than the non-PF fraction, suggesting a BTK/PLCG2-mutated reservoir resident within the proliferative compartments. PF increase was also present in BTK/PLCG2-unmutated cases at progression, indicating that PF evaluation could represent a marker of CLL progression under ibrutinib. Furthermore, we evidence different transcriptomic profiles of PF at progression in cases with or without BTK/PLCG2 mutations, suggestive of a reactivation of B-cell receptor signaling or the emergence of bypass signaling through MYC and/or Toll-Like-Receptor-9. Clinically, longitudinal monitoring of the CXCR4dim/CD5bright PF by flow cytometry may provide a simple tool helping to intercept CLL progression under ibrutinib therapy.

Prevalence of amyloid in ligamentum flavum of patients with lumbar spinal stenosis.

BACKGROUND: Transthyretin (ATTR) amyloidosis is often diagnosed in an advanced stage, when irreversible cardiac damage has occurred. Lumbar spinal stenosis (LSS) may precede cardiac ATTR amyloidosis by many years, offering the opportunity to detect ATTR already at the time of LSS surgery. We prospectively assessed the prevalence of ATTR in the ligamentum flavum by tissue biopsy in patients aged >50 years undergoing surgery for LSS. METHODS: Ligamentum flavum thickness was assessed pre-operatively on axial T2 magnetic resonance imaging (MRI) slices. Tissue samples from ligamentum flavum were screened centrally by Congo red staining and immunohistochemistry (IHC). RESULTS: Amyloid in the ligamentum flavum was detected in 74/94 patients (78.7%). IHC revealed ATTR in 61 (64.9%), whereas amyloid subtyping was inconclusive in 13 (13.8%). Mean thickness of ligamentum flavum was significantly higher at all levels in patients with amyloid (p < .05). Patients with amyloid deposits were older (73.1 ± 9.2 vs. 64.6 ± 10.1 years, p = .01). No differences in sex, comorbidities, previous surgery for carpal tunnel syndrome or LSS were observed. CONCLUSIONS: Amyloid, mostly of the ATTR subtype, was found in four out of five patients with LSS and is associated with age and ligamentum flavum thickness. Histopathological work-up of ligamentum flavum might inform future decision making.

HTGQC and shinyHTGQC: an R package and shinyR application for quality controls of HTG EDGE-seq protocols.

Extraction-free HTG EdgeSeq protocols are used to profile sets of genes and measure their expression. Thus, these protocols are frequently used to characterise tumours and their microenvironments. However, although positive and control genes are provided, little indication is given concerning the assessment of the technical success of each sample within the sequencing run. We developed HTGQC, an R package for the quality control of HTG EdgeSeq protocols. Additionally, shinyHTGQC is a shiny application for users without computing knowledge, providing an easy-to-use interface for data quality control and visualisation. Quality checks can be performed on the raw sequencing outputs, and samples are flagged as FAIL or ALERT based on the expression levels of the positive and negative control genes. Availability & Implementation: The code is freely available at https://github.com/LodovicoTerzi/HTGQC (R package) and https://lodovico.shinyapps.io/shinyHTGQC/ (shiny application), including test datasets.

Endoscopic Evacuation of Massive Intraventricular Hemorrhages Reduces Shunt Dependency: A Meta-Analysis.

Intraventricular hemorrhage (IVH) is characterized by severe prognosis. The amount of intraventricular blood is the most important, disease-specific, prognostic factor, as acute complications are strictly dependent on clot formation. Although external ventricular drain (EVD) placement is the standard treatment, in the past 15 years neuroendoscopic (NE) evacuation of IVH has been advocated, but available comparative data are limited. A systematic review of the literature was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Included articles compare the treatment of primary and secondary IVH with NE and EVD. The meta-analysis was performed in terms of shunt dependency. Cochran's Q-test and I2 statistics were used to assess heterogeneity in the studies. No heterogeneity was considered for p greater than 0.05 and I2 less than 20%. A random-effect model was used, with restricted maximum likelihood to estimate the heterogeneity variance. After screening 744 articles, 5 were included in the meta-analysis. A total of 303 patients presenting with primary or pure (50 patients) and secondary (253 patients) IVH, undergoing either NE (151) or EVD (152), were included in the metanalysis. The risk of ventriculoperitoneal (VP) shunt was higher in the EVD group (relative risk: 1.93, 95% confidence interval: 1.28-2.92, p = 0.0094). The risk of VP shunt was higher in the EVD group, but the overall outcome remains poor for patients with IVH, with a moderate-to-high disability. Large randomized controlled trials are needed to evaluate more deeper both advantages and effects on the outcome of NE over EVD.

Preliminary Validation of FoRCaSco: A New Grading System for Cerebral and Cerebellar Cavernomas.

OBJECTIVE: Surgical indications for cerebral cavernous malformations (CCMs) remain significantly center- and surgeon-dependent; available grading systems are potentially limited, as they do not include epileptologic and radiologic data. Several experienced authors proposed a new grading system for CCM and the first group of patients capable of providing its statistical validation was analyzed. METHODS: A retrospective series of 289 CCMs diagnosed between 2008 and 2021 was collected in a shared anonymous database among 9 centers. The new grading system ranges from -1 to 10. For each patient with cortical and cerebellar cavernous malformations the grading system was applied, and a retrospective outcome analysis was performed. We proposed a score of 4 as a cutoff for surgical indication. RESULTS: Operated patients with a score ≥4 were grouped with non-operated patients with a score <4, as they constituted the group that received correct treatment according to the new grading system. Patients with a score ≥4, who underwent surgery and had an improved outcome, were compared to patients with a score ≥4 who were not operated (P = 0.04), and to patients with a score <4 who underwent surgery (P < 0.001). CONCLUSIONS: This preliminary statistical analysis demonstrated that this new grading would be applicable in surgical reality. The cutoff score of 4 correctly separated the patients who could benefit from surgical intervention from those who would not. The outcome analysis showed that the treated patients in whom the grading system has been correctly applied have a better outcome than those in whom the grading system has not been applied.

CyberKnife for Recurrent Malignant Gliomas: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVE: Possible treatment strategies for recurrent malignant gliomas include surgery, chemotherapy, radiotherapy, and combined treatments. Among different reirradiation modalities, the CyberKnife System has shown promising results. We conducted a systematic review of the literature and a meta-analysis to establish the efficacy and safety of CyberKnife treatment for recurrent malignant gliomas. METHODS: We searched PubMed, MEDLINE, and EMBASE from 2000 to 2021 for studies evaluating the safety and efficacy of CyberKnife treatment for recurrent WHO grade III and grade IV gliomas of the brain. Two independent reviewers selected studies and abstracted data. Missing information was requested from the authors via email correspondence. The primary outcomes were median Overall Survival, median Time To Progression, and median Progression-Free Survival. We performed subgroup analyses regarding WHO grade and chemotherapy. Besides, we analyzed the relationship between median Time To Recurrence and median Overall Survival from CyberKnife treatment. The secondary outcomes were complications, local response, and recurrence. Data were analyzed using random-effects meta-analysis. RESULTS: Thirteen studies reporting on 398 patients were included. Median Overall Survival from initial diagnosis and CyberKnife treatment was 22.6 months and 8.6 months. Median Time To Progression and median Progression-Free Survival from CyberKnife treatment were 6.7 months and 7.1 months. Median Overall Survival from CyberKnife treatment was 8.4 months for WHO grade IV gliomas, compared to 11 months for WHO grade III gliomas. Median Overall Survival from CyberKnife treatment was 4.4 months for patients who underwent CyberKnife treatment alone, compared to 9.5 months for patients who underwent CyberKnife treatment plus chemotherapy. We did not observe a correlation between median Time To Recurrence and median Overall Survival from CyberKnife. Rates of acute neurological and acute non-neurological side effects were 3.6% and 13%. Rates of corticosteroid dependency and radiation necrosis were 18.8% and 4.3%. CONCLUSIONS: Reirradiation of recurrent malignant gliomas with the CyberKnife System provides encouraging survival rates. There is a better survival trend for WHO grade III gliomas and for patients who undergo combined treatment with CyberKnife plus chemotherapy. Rates of complications are low. Larger prospective studies are warranted to provide more accurate results.