[Selective dorsal rhizotomy: a review of the literature on this technique for the treatment of spasticity in infantile cerebral palsy]

INTRODUCTION

Infantile cerebral palsy is a well-known condition, the prevalence of which has varied only slightly over the years. The most common subtype is spastic diplegia, and spasticity is the most disabling symptom. Its treatment involves a multidisciplinary intervention that includes rehabilitation, the use of drugs, and orthopaedic and nervous system surgery, where selective dorsal rhizotomy is a prominent procedure.

AIM

To present a thorough review of the use, indication and long-term consequences of selective dorsal rhizotomy.

DEVELOPMENT

It is a minimally invasive procedure aimed at reducing spasticity in the lower extremities in order to improve the ability to walk, lessen pain, facilitate care in everyday life and diminish the need for orthopaedic surgery. The literature contains a wide range of criteria for its use, and the main indication is spastic diplegia with the absence of dystonia. It is routinely performed in several countries, while we have no evidence of its application in ours.

CONCLUSIONS

Following the literature review, we believe there is enough experience to state that selective dorsal rhizotomy is a safe and simple technique from which many patients with spasticity of the lower limbs secondary to infantile cerebral palsy can benefit in both the short and the long term.

Phase I Study of DNX-2401 (Delta-24-RGD) Oncolytic Adenovirus: Replication and Immunotherapeutic Effects in Recurrent Malignant Glioma

Purpose DNX-2401 (Delta-24-RGD; tasadenoturev) is a tumor-selective, replication-competent oncolytic adenovirus. Preclinical studies demonstrated antiglioma efficacy, but the effects and mechanisms of action have not been evaluated in patients. Methods A phase I, dose-escalation, biologic-end-point clinical trial of DNX-2401 was conducted in 37 patients with recurrent malignant glioma. Patients received a single intratumoral injection of DNX-2401 into biopsy-confirmed recurrent tumor to evaluate safety and response across eight dose levels (group A). To investigate the mechanism of action, a second group of patients (group B) underwent intratumoral injection through a permanently implanted catheter, followed 14 days later by en bloc resection to acquire post-treatment specimens. Results In group A (n = 25), 20% of patients survived > 3 years from treatment, and three patients had a ≥ 95% reduction in the enhancing tumor (12%), with all three of these dramatic responses resulting in > 3 years of progression-free survival from the time of treatment. Analyses of post-treatment surgical specimens (group B, n = 12) showed that DNX-2401 replicates and spreads within the tumor, documenting direct virus-induced oncolysis in patients. In addition to radiographic signs of inflammation, histopathologic examination of immune markers in post-treatment specimens showed tumor infiltration by CD8+ and T-bet+ cells, and transmembrane immunoglobulin mucin-3 downregulation after treatment. Analyses of patient-derived cell lines for damage-associated molecular patterns revealed induction of immunogenic cell death in tumor cells after DNX-2401 administration. Conclusion Treatment with DNX-2401 resulted in dramatic responses with long-term survival in recurrent high-grade gliomas that are probably due to direct oncolytic effects of the virus followed by elicitation of an immune-mediated antiglioma response.

The impact of intraoperative magnetic resonance in routine pediatric neurosurgical practice-a 6-year appraisal

BACKGROUND

The intraoperative magnetic resonance scanner (ioMR) was introduced in our unit in 2009, and has been used routinely since then.

OBJECTIVE

This study aims to describe indications, radiological features, and clinical outcomes of the patients operated on with ioMRI and analyze our experience.

METHODS

A retrospective analysis of a prospective surgical database has been performed, including surgical procedure, intent, radiological reports, need for second-look surgery, and complications, supplemented by further review of the clinical notes and the scans.

RESULTS

From 2009 to 2015, 255 surgical procedures with ioMR were performed: 175 were craniotomies for tumor excision, 65 were epilepsy related, and 15 were biopsies or cyst drainages. The mean age was 9.4 years. One ioMR was performed in 79.5% patients; the mean duration of the MR was 41 min. In 172 cases (67.4%), no actions followed the ioMR. When the aim of the surgery was debulking of the tumor, the percentage of patients in which the ioMR was followed by resection was higher than when complete resection was the aim (56 vs 27.5%). The complication rate was not increased when compared with our previous results (infection 1%, neurological deficits 12%).

CONCLUSION

This is the largest published series of ioMRI-aided pediatric neurosurgery to date. We have demonstrated that it can be used safely and routinely in pediatric neurosurgical procedures at any age, assisting the surgeon in achieving the best extent of resection and aiding in intra-operative decision-making for tumor- and non-tumor-related intracranial pathology.

DNX-2401, an Oncolytic Virus, for the Treatment of Newly Diagnosed Diffuse Intrinsic Pontine Gliomas: A Case Report

Diffuse intrinsic pontine gliomas (DIPGs) are aggressive glial brain tumors that primarily affect children, for which there is no curative treatment. Median overall survival is only one year. Currently, the scientific focus is on expanding the knowledge base of the molecular biology of DIPG, and identifying effective therapies. Oncolytic adenovirus DNX-2401 is a replication-competent, genetically modified virus capable of infecting and killing glioma cells, and stimulating an anti-tumor immune response. Clinical trials evaluating intratumoral DNX-2401 in adults with recurrent glioblastoma have demonstrated that the virus has a favorable safety profile and can prolong survival. Subsequently, these results have encouraged the transition of this biologically active therapy from adults into the pediatric population. To this aim, we have designed a clinical Phase I trial for newly diagnosed pediatric DIPG to investigate the feasibility, safety, and preliminary efficacy of delivering DNX-2401 into tumors within the pons following biopsy. This case report presents a pediatric patient enrolled in this ongoing Phase I trial for children and adolescents with newly diagnosed DIPG. The case involves an 8-year-old female patient with radiologically diagnosed DIPG who underwent stereotactic tumor biopsy immediately followed by intratumoral DNX-2401 in the same biopsy track. Because there were no safety concerns or new neurological deficits, the patient was discharged 3 days after the procedures. To our knowledge, this is the first report of intratumoral DNX-2401 for a patient with DIPG in a clinical trial. We plan to demonstrate that intratumoral delivery of an oncolytic virus following tumor biopsy for pediatric patients with DIPG is a novel and feasible approach and that DNX-2401 represents an innovative treatment for the disease.

Microplastic ingestion by Mullus surmuletus Linnaeus, 1758 fish and its potential for causing oxidative stress

A total of 417 striped red mullet, Mullus surmuletus, were analyzed to study microplastic ingestion and livers of fish were assessed to study effects of microplastics. Nearly one third (27.30%) of the individuals were quantified to ingest microplastics although there was no evidence of oxidative stress or cellular damage in the liver of fish which had ingested microplastics. A small increase in the activity of glutathione S-transferase (GST) of M. surmuletus was detected which could be suggesting an induction of the detoxification systems but these findings should be tested in laboratory conditions under a controlled diet and known concentration of microplastics. Fish from trammel fisheries, operating closer to land and targeting larger individuals, showed higher mean ingestion values than fish from trawling fisheries, and were related to body size, as microplastics ingested increased with total fish length. Consequently, ingestion values of microplastics were not related to sampling distance from land giving further evidence of the ubiquity of microplastics in the marine environment. Finally, Fourier Transform Infrared Spectroscopy (FTIR) analysis showed that the vast majority of microplastics were filament type and polyethylene terephthalate (PET) was the main identified component.

Abstract LB-235: Delta-24-RGD oncolytic adenovirus treatment downmodulates the key regulator of T-cell exhaustion TIM3 in malignant gliomas

T cell exhaustion is a key mechanism of tumor immune suppression and is commonly observed in several cancers. The exhausted T cells in the tumor microenvironment overexpress inhibitory receptors, show decreased effector cytokine production, and exhibit diminished cytolytic capabilities, resulting in the failure to eliminate cancer cells. Restoring the activity of exhausted T cells is a desirable strategy to improve immune-based anti-cancer therapies, and has yielded encouraging results. Exhausted T cells are characterized by the expression of high levels of PD-1 and TIM3, which cooperate to induce T-cell hyporesponsiveness. In this study, we sought to determine whether the infection of human gliomas with oncolytic viruses modifies the expression of T cell markers. As part of a phase 1, dose-escalation, biological-endpoint clinical study (NCT00805376) of Delta-24-RGD, a Rb-targeted, tumor-selective, replication-competent oncolytic adenovirus, conducted in 37 patients with recurrent malignant glioma, 12 patients received an intratumoral injection through an implanted catheter, followed 14-days later by en bloc resection and Delta-24-RGD injections into the post-resection tumor bed. 10 surgical post-treatment specimens and 5 pre-treated tumors were examined for markers of immune response. From all selected cases, formalin fixed, paraffin embedded tissue blocks were examined. IHC was performed using a Leica Bond Max automated stainer as previously described. The slides were scanned in an Aperio AT2 scanner (Leica Biosystems). The IHC scores for CD3, CD4, CD8, CD45Ro, FOXP3, TIM3, LAG-3, VISTA, CD20, CD57, CD68, and OX40 were expressed as cell density in the inflammatory cell population (number of positive cells per mm square of tumor area), except PD-L1, PD-L2, B7-H3, B7-H4, IDO-1, which were expressed using percentage of positive tumor cells, and also as H-Score of the tumor cells (which integrates percentage of tumor cells and intensity of staining, with a final H-score ranging from 0 to 300). Correlations between immunostaining marker values and survival and dose level were assessed using Spearman rank correlation analysis. Differences in immunostaining marker values before and after treatment were assessed using the Wilcoxon rank sum test. These analyses demonstrated that all the target proteins are expressed in gliomas in different patterns and tumor regions. Although, we did not observe significant treatment-related changes in the expression of PD-1 in lymphocytes and PD-L1 in glioma cells, TIM3, a marker for T cell exhaustion, was downregulated after Delta-24-RGD treatment. In addition, expression of B7-H3, a marker of poor prognosis in other tumors, correlated with poorer survival. Because PD-1 and TIM3 cooperate to maintain T-cell exhaustion our data provide a rationale for the combination of Delta-24-RGD and anti-PD-1 antibodies for the treatment of malignant gliomas. Importantly, a multicenter clinical trial to test this strategy has already been open (NCT02798406).

Citation Format: Juan Fueyo, Candelaria Gomez-Manzano, Pamela Villalobos, Jaime Rodriguez-Canales, Barbara Mino, Ignacio Wistuba, Kenneth Hess, Marta Alonso, Sonia Tejada, Ricardo Diez-Valle, Brett Ewald, Frank Tufaro, Frederick Lang. Delta-24-RGD oncolytic adenovirus treatment downmodulates the key regulator of T-cell exhaustion TIM3 in malignant gliomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-235. doi:10.1158/1538-7445.AM2017-LB-235

A phase II trial of autologous dendritic cell vaccination and radiochemotherapy following fluorescence-guided surgery in newly diagnosed glioblastoma patients

Background

Prognosis of patients with glioblastoma multiforme (GBM) remains dismal, with median overall survival (OS) of about 15 months. It is therefore crucial to search alternative strategies that improve these results obtained with conventional treatments. In this context, immunotherapy seems to be a promising therapeutic option. We hypothesized that the addition of tumor lysate-pulsed autologous dendritic cells (DCs) vaccination to maximal safe resection followed by radiotherapy and concomitant and adjuvant temozolomide could improve patients’ survival.

Methods

We conducted a phase-II clinical trial of autologous DCs vaccination in patients with newly diagnosed patients GBM who were candidates to complete or near complete resection. Candidates were finally included if residual tumor volume was lower than 1 cc on postoperative radiological examination. Autologous DCs were generated from peripheral blood monocytes and pulsed with autologous whole tumor lysate. The vaccination calendar started before radiotherapy and was continued during adjuvant chemotherapy. Progression free survival (PFS) and OS were analyzed with the Kaplan–Meier method. Immune response were assessed in blood samples obtained before each vaccines.

Results

Thirty-two consecutive patients were screened, one of which was a screening failure due to insufficient resection. Median age was 61 years (range 42–70). Karnofsky performance score (KPS) was 90–100 in 29%, 80 in 35.5% and 60–70 in 35.5% of cases. MGMT (O⁶-methylguanine-DNA-methyltransferase) promoter was methylated in 45.2% of patients. No severe adverse effects related to immunotherapy were registered. Median PFS was 12.7 months (CI 95% 7–16) and median OS was 23.4 months (95% CI 16–33.1). Increase in post-vaccination tumor specific immune response after vaccines (proliferation or cytokine production) was detected in 11/27 evaluated patients. No correlation between immune response and survival was found.

Conclusions

Our results suggest that the addition of tumor lysate-pulsed autologous DCs vaccination to tumor resection and combined radio-chemotherapy is feasible and safe. A multicenter randomized clinical trial is warranted to evaluate the potential survival benefit of this therapeutic approach.

Trial registration This phase-II trial was registered as EudraCT: 2009-009879-35 and ClinicalTrials.gov Identifier: NCT01006044 retrospectively registered

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1202-z) contains supplementary material, which is available to authorized users.

A small noncoding RNA signature found in exosomes of GBM patient serum as a diagnostic tool

BACKGROUND

Glioblastoma multiforme (GBM) is the most frequent malignant brain tumor in adults, and its prognosis remains dismal despite intensive research and therapeutic advances. Diagnostic biomarkers would be clinically meaningful to allow for early detection of the tumor and for those cases in which surgery is contraindicated or biopsy results are inconclusive. Recent findings show that GBM cells release microvesicles that contain a select subset of cellular proteins and RNA. The aim of this hypothesis-generating study was to assess the diagnostic potential of miRNAs found in microvesicles isolated from the serum of GBM patients.

METHODS

To control disease heterogeneity, we used patients with newly diagnosed GBM. In the discovery stage, PCR-based TaqMan Low Density Arrays followed by individual quantitative reverse transcriptase polymerase chain reaction were used to test the differences in the miRNA expression levels of serum microvesicles among 25 GBM patients and healthy controls paired by age and sex. The detected noncoding RNAs were then validated in another 50 GBM patients.

RESULTS

We found that the expression levels of 1 small noncoding RNA (RNU6-1) and 2 microRNAs (miR-320 and miR-574-3p) were significantly associated with a GBM diagnosis. In addition, RNU6-1 was consistently an independent predictor of a GBM diagnosis.

CONCLUSIONS

Altogether our results uncovered a small noncoding RNA signature in microvesicles isolated from GBM patient serum that could be used as a fast and reliable differential diagnostic biomarker.

Factors associated with a higher rate of distant failure after primary treatment for glioblastoma

Our purpose was to analyze the pattern of failure in glioblastoma (GBM) patients at first recurrence after radiotherapy and temozolomide and its relationship with different factors. From 77 consecutive GBM patients treated at our institution with fluorescence guided surgery and standard radiochemotherapy, 58 first recurrences were identified and included in a retrospective review. Clinical data including age, Karnofsky performance score, preoperative tumor volume and location, extend of resection, MGMT promoter methylation status, time to progression (PFS), overall survival (OS) and adjuvant therapies were reviewed for every patient. Recurrent tumor location respect the original lesion was the end point of the study. The recurrence pattern was local only in 65.5% of patients and non-local in 34.5%. The univariate and multivariate analysis showed that greater preoperative tumor volume in T1 gadolinium enhanced sequences, was the only variable with statistical signification (p < 0.001) for increased rate of non-local recurrences, although patients with MGMT methylation and complete resection of enhancing tumor presented non-local recurrences more frequently. PFS was longer in patients with non-local recurrences (13.8 vs. 6.4 months; p = 0.019, log-rank). However, OS was not significantly different in both groups (24.0 non-local vs. 19.3 local; p = 0.9). Rate of non-local recurrences in our series of patients treated with fluorescence guided surgery and standard radiochemotherapy was higher than previously published in GBM, especially in patients with longer PFS. Greater preoperative enhancing tumor volume was associated with increased rate of non-local recurrences.