scholarly journals Pharmacodynamic Analysis of Magnetic Resonance Imaging-Monitored Focused Ultrasound-Induced Blood-Brain Barrier Opening for Drug Delivery to Brain Tumors

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Po-Chun Chu ◽  
Wen-Yen Chai ◽  
Han-Yi Hsieh ◽  
Jiun-Jie Wang ◽  
Shiaw-Pyng Wey ◽  
...  

Microbubble-enhanced focused ultrasound (FUS) can enhance the delivery of therapeutic agents into the brain for brain tumor treatment. The purpose of this study was to investigate the influence of brain tumor conditions on the distribution and dynamics of small molecule leakage into targeted regions of the brain after FUS-BBB opening. A total of 34 animals were used, and the process was monitored by 7T-MRI. Evans blue (EB) dye as well as Gd-DTPA served as small molecule substitutes for evaluation of drug behavior. EB was quantified spectrophotometrically. Spin-spin (R1) relaxometry and area under curve (AUC) were measured by MRI to quantify Gd-DTPA. We found that FUS-BBB opening provided a more significant increase in permeability with small tumors. In contrast, accumulation was much higher in large tumors, independent of FUS. The AUC values of Gd-DTPA were well correlated with EB delivery, suggesting that Gd-DTPA was a good indicator of total small-molecule accumulation in the target region. The peripheral regions of large tumors exhibited similar dynamics of small-molecule leakage after FUS-BBB opening as small tumors, suggesting that FUS-BBB opening may have the most significant permeability-enhancing effect on tumor peripheral. This study provides useful information toward designing an optimized FUS-BBB opening strategy to deliver small-molecule therapeutic agents into brain tumors.

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 15
Author(s):  
Sheng-Kai Wu ◽  
Chia-Lin Tsai ◽  
Yuexi Huang ◽  
Kullervo Hynynen

The presence of blood–brain barrier (BBB) and/or blood–brain–tumor barriers (BBTB) is one of the main obstacles to effectively deliver therapeutics to our central nervous system (CNS); hence, the outcomes following treatment of malignant brain tumors remain unsatisfactory. Although some approaches regarding BBB disruption or drug modifications have been explored, none of them reach the criteria of success. Convention-enhanced delivery (CED) directly infuses drugs to the brain tumor and surrounding tumor infiltrating area over a long period of time using special catheters. Focused ultrasound (FUS) now provides a non-invasive method to achieve this goal via combining with systemically circulating microbubbles to locally enhance the vascular permeability. In this review, different approaches of delivering therapeutic agents to the brain tumors will be discussed as well as the characterization of BBB and BBTB. We also highlight the mechanism of FUS-induced BBB modulation and the current progress of this technology in both pre-clinical and clinical studies.


2012 ◽  
Vol 32 (1) ◽  
pp. E4 ◽  
Author(s):  
Hao-Li Liu ◽  
Hung-Wei Yang ◽  
Mu-Yi Hua ◽  
Kuo-Chen Wei

Malignant glioma is a severe primary CNS cancer with a high recurrence and mortality rate. The current strategy of surgical debulking combined with radiation therapy or chemotherapy does not provide good prognosis, tumor progression control, or improved patient survival. The blood-brain barrier (BBB) acts as a major obstacle to chemotherapeutic treatment of brain tumors by severely restricting drug delivery into the brain. Because of their high toxicity, chemotherapeutic drugs cannot be administered at sufficient concentrations by conventional delivery methods to significantly improve long-term survival of patients with brain tumors. Temporal disruption of the BBB by microbubble-enhanced focused ultrasound (FUS) exposure can increase CNS-blood permeability, providing a promising new direction to increase the concentration of therapeutic agents in the brain tumor and improve disease control. Under the guidance and monitoring of MR imaging, a brain drug-delivery platform can be developed to control and monitor therapeutic agent distribution and kinetics. The success of FUS BBB disruption in delivering a variety of therapeutic molecules into brain tumors has recently been demonstrated in an animal model. In this paper the authors review a number of critical studies that have demonstrated successful outcomes, including enhancement of the delivery of traditional clinically used chemotherapeutic agents or application of novel nanocarrier designs for actively transporting drugs or extending drug half-lives to significantly improve treatment efficacy in preclinical animal models.


Author(s):  
Shoaib Amin Banday ◽  
Mohammad Khalid Pandit

Introduction: Brain tumor is among the major causes of morbidity and mortality rates worldwide. According to National Brain Tumor Foundation (NBTS), the death rate has nearly increased by as much as 300% over last couple of decades. Tumors can be categorized as benign (non-cancerous) and malignant (cancerous). The type of the brain tumor significantly depends on various factors like the site of its occurrence, its shape, the age of the subject etc. On the other hand, Computer Aided Detection (CAD) has been improving significantly in recent times. The concept, design and implementation of these systems ascend from fairly simple ones to computationally intense ones. For efficient and effective diagnosis and treatment plans in brain tumor studies, it is imperative that an abnormality is detected at an early stage as it provides a little more time for medical professionals to respond. The early detection of diseases has predominantly been possible because of medical imaging techniques developed from past many decades like CT, MRI, PET, SPECT, FMRI etc. The detection of brain tumors however, has always been a challenging task because of the complex structure of the brain, diverse tumor sizes and locations in the brain. Method: This paper proposes an algorithm that can detect the brain tumors in the presence of the Radio-Frequency (RF) inhomoginiety. The algorithm utilizes the Mid Sagittal Plane as a landmark point across which the asymmetry between the two brain hemispheres is estimated using various intensity and texture based parameters. Result: The results show the efficacy of the proposed method for the detection of the brain tumors with an acceptable detection rate. Conclusion: In this paper, we have calculated three textural features from the two hemispheres of the brain viz: Contrast (CON), Entropy (ENT) and Homogeneity (HOM) and three parameters viz: Root Mean Square Error (RMSE), Correlation Co-efficient (CC), and Integral of Absolute Difference (IAD) from the intensity distribution profiles of the two brain hemispheres to predict any presence of the pathology. First a Mid Sagittal Plane (MSP) is obtained on the Magnetic Resonance Images that virtually divides brain into two bilaterally symmetric hemispheres. The block wise texture asymmetry is estimated for these hemispheres using the above 6 parameters.


2021 ◽  
Vol 11 (10) ◽  
pp. 133-144
Author(s):  
Dipak Chaulagain ◽  
Volodymyr Smolanka ◽  
Andriy Smolanka

People, in general, are affected by a brain or intracranial tumor when abnormal cells started functioning within their brain. This paper explores mainly tumors that affect the brain. Almost every type of brain tumor might create symptoms which are based on the parts of the brain affected. In order to better understand reasons of occurrence intracranial tumors in various sections of the population, the study examined the relationship between sociodemographic variables, i.e., age, gender and marital status and the relative frequency of intracranial tumors as part of a study. Samples are collected based on the information from Uzhhorod Regional Center of Neurosurgery and Neurology in Ukraine. And factors such as age, gender and marital status has been considered to examine tumor size variation. The ratios of organ cancers in Ukrainians are evidently increasing. Besides, there has been growing trend in affected rates in both the genders of CNS cancers have been noticed in all the records. The ratio of most harmful brain tumors is comparatively in minimal ratio in East and Southeast Asia, and India. On the other hand, the highest ratio has been noted in European countries and as well United States, and Ukraine is one of those countries. The major burdens of cancer frequency in Ukraine have been noticed in the lung, breast, and prostate and brain. Of these, brain tumor rate in Ukraine had been hardly studied. The major difference in frequency in Asian and European populations implies the potential influence of genetic or environmental factors in malignant brain tumors. Continuing monitoring of tumor ratio in Ukraine is essential to comprehend how best to reduce cancer burden globally and to explain the causes of provincial variations, for example access to diagnosis methods and ecological exposures. Key words: Intracranial tumors, symptoms, tumor incidence in Ukraine, treatment plans, survival rate of cancer in Ukraine.


Neurographics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 175-185
Author(s):  
B. Rao ◽  
I. Ikuta ◽  
A. Mahajan ◽  
A.A. Karam ◽  
V.M. Zohrabian

Brain tumors are a diverse group of neoplasms that are a source of substantial morbidity and mortality worldwide. Primary gliomas constitute almost all malignant brain tumors, with the most aggressive as well as most common form in adults, grade IV glioma or glioblastoma multiforme, carrying an especially poor prognosis. Neuroimaging is critical not only in the identification of CNS tumor but also in treatment-planning and assessing the response to therapy. Structured reporting continues to gain traction in radiology by reducing report ambiguity and improving consistency, while keeping referring clinicians and patients informed. The Brain Tumor Reporting and Data System (BT-RADS) is a relatively new paradigm that attempts to simplify and maximize consistency in radiologic reporting. BT-RADS incorporates MR imaging features, clinical assessment, and timing of therapy to assign each study a score or category, which is, in turn, linked to a management suggestion. The purpose of this pictorial review article is to familiarize radiologists and nonradiology neurologic specialists alike with BT-RADS, highlighting both advantages and limitations, in the hope that adoption of this system might ultimately facilitate more effective communication and improve consistency among reports.Learning Objective: To describe the features and underscore the advantages and disadvantages of the Brain Tumor Reporting and Data System (BT-RADS), a relatively new classification system that attempts to simplify and maximize consistency in radiologic reporting


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e18509-e18509
Author(s):  
Mehee Choi ◽  
Brian P. Martin ◽  
Lisa Misell ◽  
Joseph M. Zabramski ◽  
David G. Brachman

e18509 Background: Many patients with brain tumors face challenges with access to care. For rural patients, prolonged travel times may limit access to appropriate radiotherapy. Radiation centers (RCs) offering specialized brain radiotherapy, e.g., stereotactic radiosurgery (SRS), are geographically limited. Utilization of brain brachytherapy at the time of resection offers an option for such patients, but technical challenges have limited the adoption. To address the limitations of traditional brachytherapy, a device with Cs-131 seeds embedded in a bioresorbable collagen tile (GammaTile, GT Medical Technologies, Tempe, AZ USA) was developed. GammaTile (GT) is FDA-cleared for permanent implantation at the time of resection for all recurrent intracranial tumors and for newly diagnosed malignant intracranial neoplasms. To investigate if wider availability of this treatment could possibly lower the geographic barrier to access to care, we mapped the US population against existing RCs with brain tumor expertise and neurosurgery centers (NSCs) performing craniotomies. Methods: We analyzed 2018 CMS claims data using CPT codes for single- and multi-fraction SRS to identify RCs with brain tumor treatment expertise and mapped these against the population. Using similar methodology, using CPT codes for craniotomies, we identified NSCs, as any facility performing craniotomies is potentially eligible to implant GT. Results: 135 RCs used CPT codes for SRS. 193-, 119-, 82-, and 52-million Americans lived >30-, >60-, >90-, and >120-minutes from one of these centers, respectively. 530 NSCs preform craniotomies, including ≥1 in every state, a 4-fold increase over the number of RCs offering SRS. Conclusions: For many patients, substantial travel distances limit their access to RCs with brain tumor treatment expertise. In contrast, the 530 craniotomy-performing NSCs have far greater geographic dispersion. The option of undergoing brain radiation with GT implantation at the time of brain tumor craniotomy brings treatment closer to millions, ensures compliance, and reduces additional travel for follow-up radiation treatment.[Table: see text]


2019 ◽  
Vol 1 (Supplement_2) ◽  
pp. ii12-ii12
Author(s):  
Michiharu Yoshida ◽  
Kazuo Maruyama ◽  
Yasutaka Kato ◽  
Rachmilevitch Itay ◽  
Syuji Suzuki ◽  
...  

Abstract OBJECTIVE In neuro-oncology, it is believed that one major obstacle to effective chemotherapy is the high vascularity and heterogenous permeability of brain tumors. Focused ultrasound (FUS) exposure with the microbubbles has been shown to transiently open the blood-brain barrier (BBB) without depositing thermal energy, and thus may enhance the delivery of various therapeutic drugs into brain tumors. The aim of this study was to evaluate the BBB opening using 220-kHz transcranial MRI-guided FUS (TcMRgFUS) device and microbubbles in mouse and rat. METHODS The experiments were performed with the 220-kHz ExAblate Neuro TcMRgFUS system (InSightec) and novel lipid bubbles (LB, Teikyo Univ.). Normal mouse and rat brains were irradiated with TcMRgFUS (output power, 5W; duration of irradiation, 30 s; duty cycle 100%) following intravenous injection of 6x107 LB per mouse and rat, respectively. On irradiation, target temperature rise & cavitation signal were monitored by MR thermometry and cavitation receiver, respectively. Immediately after irradiation, BBB opening and complications were detected based on T1, T2, T2*, and Gadolinium (Gd) enhanced T1-weighted images. RESULTS The maximum temperature of brain tissue was under 42 C. There were no risky-cavitation signals causing hemorrhage. The FUS-LB exposure induced successful BBB opening effect in both mouse and rat, confirmed by Gd enhancement in the target region, lateral ventricles, and sulcus. In addition, there were no complications such as edema, coagulation, and hemorrhage. CONCLUSIONS Although there remain many conditions to be optimized, BBB opening using a 220-kHz TcMRgFUS device and LB can offer a non-invasive and feasible drug delivery for brain malignancies.


2019 ◽  
Vol 12 (4) ◽  
pp. 466-480
Author(s):  
Li Na ◽  
Xiong Zhiyong ◽  
Deng Tianqi ◽  
Ren Kai

Purpose The precise segmentation of brain tumors is the most important and crucial step in their diagnosis and treatment. Due to the presence of noise, uneven gray levels, blurred boundaries and edema around the brain tumor region, the brain tumor image has indistinct features in the tumor region, which pose a problem for diagnostics. The paper aims to discuss these issues. Design/methodology/approach In this paper, the authors propose an original solution for segmentation using Tamura Texture and ensemble Support Vector Machine (SVM) structure. In the proposed technique, 124 features of each voxel are extracted, including Tamura texture features and grayscale features. Then, these features are ranked using the SVM-Recursive Feature Elimination method, which is also adopted to optimize the parameters of the Radial Basis Function kernel of SVMs. Finally, the bagging random sampling method is utilized to construct the ensemble SVM classifier based on a weighted voting mechanism to classify the types of voxel. Findings The experiments are conducted over a sample data set to be called BraTS2015. The experiments demonstrate that Tamura texture is very useful in the segmentation of brain tumors, especially the feature of line-likeness. The superior performance of the proposed ensemble SVM classifier is demonstrated by comparison with single SVM classifiers as well as other methods. Originality/value The authors propose an original solution for segmentation using Tamura Texture and ensemble SVM structure.


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