Focused ultrasound for the treatment of brain tumors.

This review investigates focused ultrasound for treating neuro-oncological diseases as an emerging treatment modality. The technique is based on focused ultrasound waves guided by MRI. By using high or low-frequency waves, thermoablation of smaller tissue volumes centrally in the brain or a safe, temporary opening of the blood-brain barrier can be carried out for better penetration of chemotherapy. Numerous studies on neuro-oncological treatments are ongoing, signaling increasing popularity for the technique in the near future.

von Hippel-Lindau disease: Updated guideline for diagnosis and surveillance.

von Hippel Lindau disease (vHL) is caused by a hereditary predisposition to multiple neoplasms, especially hemangioblastomas in the retina and CNS, renal cell carcinomas (RCC), pheochromocytomas, neuroendocrine pancreatic tumours (PNET) and endolymphatic sac tumours. Evidence based approaches are needed to ensure an optimal clinical care, while minimizing the burden for the patients and their families. This guideline is based on evidence from the international vHL literature and extensive research of geno- and phenotypic characteristics, disease progression and surveillance effect in the national Danish vHL cohort. We included the views and preferences of the Danish vHL patients, ensured consensus among Danish experts and compared with international recommendations. RECOMMENDATIONS: vHL can be diagnosed on clinical criteria, only; however, in most cases the diagnosis can be supported by identification of a pathogenic or likely pathogenic variant in VHL. Surveillance should be initiated in childhood in persons with, or at risk of, vHL, and include regular examination of the retina, CNS, inner ear, kidneys, neuroendocrine glands, and pancreas. Treatment of vHL manifestations should be planned to optimize the chance of cure, without unnecessary sequelae. Most manifestations are currently treated by surgery. However, belzutifan, that targets HIF-2α was recently approved by the U.S. Food and Drug Administration (FDA) for adult patients with vHL-associated RCC, CNS hemangioblastomas, or PNETs, not requiring immediate surgery. Diagnostics, surveillance, and treatment of vHL can be undertaken successfully by experts collaborating in multidisciplinary teams. Systematic registration, collaboration with patient organisations, and research are fundamental for the continuous improvement of clinical care and optimization of outcome with minimal patient inconvenience.

OptimalTTF-1: Enhancing tumor treating fields therapy with skull remodeling surgery. A clinical phase I trial in adult recurrent glioblastoma.

BACKGROUND: Preclinical studies suggest that skull remodeling surgery (SR-surgery) increases the dose of tumor treating fields (TTFields) in glioblastoma (GBM) and prevents wasteful current shunting through the skin. SR-surgery introduces minor skull defects to focus the cancer-inhibiting currents toward the tumor and increase the treatment dose. This study aimed to test the safety and feasibility of this concept in a phase I setting. METHODS: Fifteen adult patients with the first recurrence of GBM were treated with personalized SR-surgery, TTFields, and physician's choice oncological therapy. The primary endpoint was toxicity and secondary endpoints included standard efficacy outcomes. RESULTS: SR-surgery resulted in a mean skull defect area of 10.6 cm2 producing a median TTFields enhancement of 32% (range 25-59%). The median TTFields treatment duration was 6.8 months and the median compliance rate 90%. Patients received either bevacizumab, bevacizumab/irinotecan, or temozolomide rechallenge. We observed 71 adverse events (AEs) of grades 1 (52%), 2 (35%), and 3 (13%). There were no grade 4 or 5 AEs or intervention-related serious AEs. Six patients experienced minor TTFields-induced skin rash. The median progression-free survival (PFS) was 4.6 months and the PFS rate at 6 months was 36%. The median overall survival (OS) was 15.5 months and the OS rate at 12 months was 55%. CONCLUSIONS: TTFields therapy combined with SR-surgery and medical oncological treatment is safe and nontoxic and holds the potential to improve the outcome for GBM patients through focal dose enhancement in the tumor.

[Diagnosis, monitoring and treatment of tuberous sclerosis complex].

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder with highly varying disease manifestations, many of which cause extensive morbidity. There are international consensus criteria for the diagnosis, monitoring and treatment of TSC, and approved medical treatment for some of the most serious disease manifestations. However, organisation of a rational and coordinated care of TSC patients involves many different medical specialities and is only sparsely described. This review describes the interdisciplinary care of TSC patients at Aarhus University Hospital, Denmark.

[Tumor treating fields in cancer treatment in Denmark].

Tumor treating fields (TTFields) is a new non-invasive approach to cancer treatment. TTFields is low-intensity (1-5 V/m), intermediate frequency (150-200 kHz) alternating electric fields delivered locally to the tumour to selectively kill dividing cells and disrupt cancer growth. TTFields has proven safe and effective for newly diagnosed glioblastoma and is currently being tried for multiple other tumours. This review presents an introduction to TTFields, covering the main indications, the application method, the mechanism of action, the clinical results and the perspectives for implementation in Danish cancer treatment.

[Tumor treating fields in cancer treatment in Denmark].

Tumor treating fields (TTFields) is a new non-invasive approach to cancer treatment. TTFields are low-intensity (1-5 V/m), intermediate frequency (150-200 kHz) alternating electric fields delivered locally to the tumour to selectively kill dividing cells and disrupt cancer growth. TTFields has proven safe and effective for newly diagnosed glioblastoma and is currently being tried for multiple other tumours. This review presents an introduction to TTFields, covering the main indications, the application method, the mechanism of action, the clinical results and the perspectives for implementation in Danish cancer treatment.

Spatial distribution of malignant tissue in gliomas: correlations of 11C-L-methionine positron emission tomography and perfusion- and diffusion-weighted magnetic resonance imaging.

BACKGROUND: The prognosis of glioma patients is contingent on precise target selection for stereotactic biopsies and the extent of tumor resection. (11)C-L-methionine (MET) positron emission tomography (PET) demonstrates tumor heterogeneity and invasion with high diagnostic accuracy. PURPOSE: To compare the spatial tumor distribution delineated by MET PET with that by perfusion- and diffusion-weighted magnetic resonance imaging (MRI), in order to understand the diagnostic value of these MRI methods, when PET is not available. MATERIAL AND METHODS: Presurgical MET PET and MRI, including perfusion- and diffusion-weighted MRI, were acquired in 13 patients (7 high-grade gliomas, 6 low-grade gliomas). A quantitative volume of interest analysis was performed to compare the modalities objectively, supplemented by a qualitative evaluation that assessed the clinical applicability. RESULTS: The inaccuracy of conventional MRI was confirmed (area under the curve for predicting voxels with high MET uptake = 0.657), whereas cerebral blood volume (CBV) maps calculated from perfusion data improved accuracy (area under the curve = 0.760). We considered CBV maps diagnostically comparable to MET PET in 5/7 cases of high-grade gliomas, but insufficient in all cases of low-grade gliomas when evaluated subjectively. Cerebral blood flow and apparent diffusion coefficient maps did not contribute to further accuracy. CONCLUSION: Adding perfusion-weighted MRI to the presurgical protocol can increase the diagnostic accuracy of conventional MRI and is a simple and well-established method compared to MET PET. However, the definition of low-grade gliomas with subtle or no alterations on cerebral blood volume maps remains a diagnostic challenge for stand-alone MRI.

Predicting the "usefulness" of 5-ALA-derived tumor fluorescence for fluorescence-guided resections in pediatric brain tumors: a European survey.

BACKGROUND: Five-aminolevulinic acid (Gliolan, medac, Wedel, Germany, 5-ALA) is approved for fluorescence-guided resections of adult malignant gliomas. Case reports indicate that 5-ALA can be used for children, yet no prospective study has been conducted as of yet. As a basis for a study, we conducted a survey among certified European Gliolan users to collect data on their experiences with children. METHODS: Information on patient characteristics, MRI characteristics of tumors, histology, fluorescence qualities, and outcomes were requested. Surgeons were further asked to indicate whether fluorescence was "useful", i.e., leading to changes in surgical strategy or identification of residual tumor. Recursive partitioning analysis (RPA) was used for defining cohorts with high or low likelihoods for useful fluorescence. RESULTS: Data on 78 patients <18 years of age were submitted by 20 centers. Fluorescence was found useful in 12 of 14 glioblastomas (85 %), four of five anaplastic astrocytomas (60 %), and eight of ten ependymomas grades II and III (80 %). Fluorescence was found inconsistently useful in PNETs (three of seven; 43 %), gangliogliomas (two of five; 40 %), medulloblastomas (two of eight, 25 %) and pilocytic astrocytomas (two of 13; 15 %). RPA of pre-operative factors showed tumors with supratentorial location, strong contrast enhancement and first operation to have a likelihood of useful fluorescence of 64.3 %, as opposed to infratentorial tumors with first surgery (23.1 %). CONCLUSIONS: Our survey demonstrates 5-ALA as being used in pediatric brain tumors. 5-ALA may be especially useful for contrast-enhancing supratentorial tumors. These data indicate controlled studies to be necessary and also provide a basis for planning such a study.

[Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant gliomas--a new treatment modality]. / 5-aminolevulinsyre-fluorescens-vejledt resektion af maligne gliomer er en ny behandlingsmodalitet.

5-aminolevulinic acid (ALA) is a precursor of haemoglobin which leads to the synthesis of porphyrins in malignant gliomas which then appears with red fluorescence under blue light. In the literature we see that there is class Ib evidence that 5-ALA guided surgery significantly increases the radicalism of surgery and gives rise to a marked improvement in 6-month progression-free survival and that there is now class II evidence confirming the value of maximal cytoreductive surgery. Furthermore, existing class II evidence indicates that there is a synergistic effect between aggressive cytoreductive surgery and radiochemotherapy.

Fluorescence-guided resection of gliomas.

INTRODUCTION: Malignant gliomas remain associated with a poor prognosis despite both surgical treatment and radiochemotherapy.Previous studies have shown that complete resection of contrast-enhancing tumours is achieved in less than 20-30% of patients. 5-aminolevulinic acid (5-ALA) is a pro-drug that leads to accumulation of fluorescent protoporphyrins in malignant gliomas. The fluorescence can be visualized intraoperatively by use of a modified microscope. The Department of Neurosurgery at Aalborg Hospital has recently adopted this new technique as the first centre in Denmark. Our preliminary results are presented as a retrospective case series. MATERIAL AND METHODS: All patients who had undergone 5-ALA fluorescence-guided surgery due to suspected malignant glioma were included. Patients received a standard preoperative dose of Gliolan. All patients had a postoperative cerebral magnetic resonance imaging scan done within 72 hours to determine their postoperative resection status. RESULTS: To date, 13 patients have undergone fluorescence-guided surgery. Total resection was achieved in 54-70% of the patients depending on the inclusion criteria. Total or near total resection was achieved in 92% of patients. CONCLUSION: The small numbers in our case series do not allow for direct comparison to be made, but show that our results on postoperative resection status fall within the range reported in other studies on the efficacy of 5-ALA. The literature offers mounting evidence in support of the role of aggressive cytoreductive surgery in patients with malignant gliomas. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

[Surgical treatment of neurocysticercosis in a 12-year old child]. / Kirurgisk behandling af neurocysticerkose hos et 12-årigt barn.

We present a case of neurocysticercosis in a 12-year old refugee from Zambia. Magnetic resonance imaging demonstrated a solitary, ring enhancing cystic lesion located subcortically in the left parietal lobe. Despite extensive diagnostic workup it was not possible to rule out alternative differential diagnoses. Serological tests for neurocysticercosis came out negative. The lesion was removed en bloc using microsurgical technique. Subsequent histological examination revealed a thick-walled cyst containing a cysticercus identifiable as a Taenia solium.