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1.
Epilepsia ; 65(1): 57-72, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37873610

ABSTRACT

OBJECTIVES: Hemimegalencephaly (HME) is a rare congenital brain malformation presenting predominantly with drug-resistant epilepsy. Hemispheric disconnective surgery is the mainstay of treatment; however, little is known about how postoperative outcomes compare across techniques. Thus we present the largest single-center cohort of patients with HME who underwent epilepsy surgery and characterize outcomes. METHODS: This observational study included patients with HME at University of California Los Angeles (UCLA) from 1984 to 2021. Patients were stratified by surgical intervention: anatomic hemispherectomy (AH), functional hemispherectomy (FH), or less-than-hemispheric resection (LTH). Seizure freedom, functional outcomes, and operative complications were compared across surgical approaches. Regression analysis identified clinical and intraoperative variables that predict seizure outcomes. RESULTS: Of 56 patients, 43 (77%) underwent FH, 8 (14%) underwent AH, 2 (4%) underwent LTH, 1 (2%) underwent unknown hemispherectomy type, and 2 (4%) were managed non-operatively. At median last follow-up of 55 months (interquartile range [IQR] 20-92 months), 24 patients (49%) were seizure-free, 17 (30%) required cerebrospinal fluid (CSF) shunting for hydrocephalus, 9 of 43 (21%) had severe developmental delay, 8 of 38 (21%) were non-verbal, and 15 of 38 (39%) were non-ambulatory. There was one (2%) intraoperative mortality due to exsanguination earlier in this cohort. Of 12 patients (29%) requiring revision surgery, 6 (50%) were seizure-free postoperatively. AH, compared to FH, was not associated with statistically significant improved seizure freedom (hazard ratio [HR] = .48, p = .328), although initial AH trended toward greater odds of seizure freedom (75% vs 46%, p = .272). Younger age at seizure onset (HR = .29, p = .029), lack of epilepsia partialis continua (EPC) (HR = .30, p = .022), and no contralateral seizures on electroencephalography (EEG) (HR = .33, p = .039) independently predicted longer duration of seizure freedom. SIGNIFICANCE: This study helps inform physicians and parents of children who are undergoing surgery for HME by demonstrating that earlier age at seizure onset, absence of EPC, and no contralateral EEG seizures were associated with longer postoperative seizure freedom. At our center, initial AH for HME may provide greater odds of seizure freedom with complications and functional outcomes comparable to those of FH.


Subject(s)
Epilepsy , Hemimegalencephaly , Hemispherectomy , Child , Humans , Hemimegalencephaly/complications , Hemimegalencephaly/surgery , Treatment Outcome , Epilepsy/drug therapy , Hemispherectomy/methods , Seizures/complications , Electroencephalography/adverse effects
2.
Ultrasound Med Biol ; 47(10): 2941-2957, 2021 10.
Article in English | MEDLINE | ID: mdl-34315620

ABSTRACT

Chemotherapeutic agents such as doxorubicin induce cell cytotoxicity through induction of DNA double-strand breaks. Recent studies have reported the occurrence of DNA double-strand breaks in different cell lines exposed to cavitational ultrasound. As ultrasound stable cavitation can potentiate the therapeutic effects of cytotoxic drugs, we hypothesized that combined treatment with unseeded stable cavitation and doxorubicin would lead to increased DNA damage and would reduce cell viability and proliferation in vitro. In this study, we describe how we determined, using 4T1 murine mammary carcinoma as a model cell line, that unseeded stable cavitation combined with doxorubicin leads to additive DNA double-strand break induction. Combined treatment with doxorubicin and unseeded stable cavitation significantly reduced cell viability and proliferation at 72 h. A mechanistic study of the potential mechanisms of action of the combined treatment identified the presence of cavitation necessary to increase early DNA double-strand break induction, likely mediated by a bystander effect with release of extracellular calcium.


Subject(s)
Antineoplastic Agents , Doxorubicin , Animals , Cell Survival , DNA/pharmacology , DNA Damage , Humans , Mice
3.
J Med Humanit ; 42(4): 659-678, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34719744

ABSTRACT

In 2018-2019, at the Keck School of Medicine of the University of Southern California (KSOM), we developed and piloted a narrative-based health systems science intervention for patients living with HIV and medical students in which medical students co-wrote patients' life narratives for inclusion in the electronic health record. The pilot study aimed to assess the acceptability of the "life narrative protocol" (LNP) from multiple stakeholder positions and characterize participants' experiences of the clinical and pedagogical implications of the LNP. Students were recruited from KSOM. Patients and staff were recruited from the Maternal, Child, and Adolescent/Adult Center for Infectious Disease and Virology (MCA) at Los Angeles County+USC Medical Center. Ten patients, seventeen students, and ten MCA staff participated in the pilot study. Qualitative methods were used to gather data from students', patients', and staff's perspectives. Three themes emerged from the thematic analysis: (1) patients' life narratives conveyed their unique life experiences and voices; (2) the protocol could result in wide-ranging effects on HIV care; (3) the LNP enabled students to contribute value to patients' healthcare. Across groups, participants considered the LNP an acceptable intervention. The LNP, its limitations, and implications for HIV care, narrative medicine, and health information technology are presented.


Subject(s)
HIV Infections , Narrative Medicine , Students, Medical , Adolescent , Adult , Child , Humans , Narration , Pilot Projects
4.
Circ Cardiovasc Qual Outcomes ; 13(5): e006043, 2020 05.
Article in English | MEDLINE | ID: mdl-32393130

ABSTRACT

BACKGROUND: Reducing hospital readmission after acute myocardial infarction (AMI) has the potential to both improve quality and reduce costs. As such, readmission after AMI has been a target of financial penalties through Medicare. However, substantial concern exists about potential adverse effects and efficacious readmission-reduction strategies are not well validated. METHODS AND RESULTS: We started an AMI readmissions reduction program in November 2017. Between July 2016 and February 2019, hospital billing data were queried to detect all inpatient hospitalizations at the Massachusetts General Hospital for AMI. Thirty-day readmission was identified through hospital billing data, and mortality was extracted from our electronic health record. The data set was merged with claims data for patients in accountable care organizations to detect readmission at other hospitals. We performed segmented linear regression, adjusting for secular trend and case mix, to assess the independent association of our program on both outcome variables. After inclusion and exclusion criteria were applied, the study population included 2020 patients. The overall 30-day readmission rate was higher before the intervention than after the intervention (15.5% versus 10.7%, P=0.002). The overall 30-day mortality rate was similar in both time periods (1.8% versus 1.4%, P=0.457). The program was associated with initial reduction in 30-day readmission (-9.8%, P=0.0002) and 30-day mortality (-2.6%, P=0.041). The program did not change trend in 30-day readmission (+0.19% readmissions/mo, P=0.554) and trend in 30-day mortality (-0.21% deaths/mo, P=0.119). CONCLUSIONS: An AMI readmissions reduction program that increases outpatient and emergency department (ED) access to cardiology care is associated with reduced 30-day readmission and 30-day mortality. Similar statistical techniques can be used to conduct a rigorous, mechanistic program evaluation of other quality improvement initiatives.


Subject(s)
Delivery of Health Care, Integrated/trends , Myocardial Infarction/therapy , Patient Care Bundles/trends , Patient Readmission/trends , Quality Improvement/trends , Quality Indicators, Health Care/trends , Aged , Aged, 80 and over , Ambulatory Care/trends , Boston , Cardiology Service, Hospital/trends , Emergency Service, Hospital/trends , Female , Humans , Male , Middle Aged , Myocardial Infarction/mortality , Program Evaluation , Time Factors , Treatment Outcome
5.
Sci Rep ; 9(1): 15581, 2019 10 30.
Article in English | MEDLINE | ID: mdl-31666639

ABSTRACT

Ultrasound-generated non-inertial cavitation has the ability to potentiate the therapeutic effects of cytotoxic drugs. We report a novel strategy to induce and regulate unseeded (without nucleation agents) non-inertial cavitation, where cavitation is initiated, monitored and regulated using a confocal ultrasound setup controlled by an instrumentation platform and a PC programmed feedback control loop. We demonstrate, using 4T1 murine mammary carcinoma as model cell line, that unseeded non-inertial cavitation potentiates the cytotoxicity of doxorubicin, one of the most potent drugs used in the treatment of solid tumors including breast cancer. Combined treatment with doxorubicin and unseeded non-inertial cavitation significantly reduced cell viability and proliferation at 72 h. A mechanistic study of the potential mechanisms of action of the combined treatment identified the presence of cavitation as required to enhance doxorubicin efficacy, but ruled out the influence of changes in doxorubicin uptake, temperature increase, hydroxyl radical production and nuclear membrane modifications on the treatment outcome. The developed strategy for the reproducible generation and maintenance of unseeded cavitation makes it an attractive method as potential preclinical and clinical treatment modality to locally potentiate doxorubicin.


Subject(s)
Doxorubicin/pharmacology , Ultrasonic Waves , Cell Line, Tumor , Cell Survival/drug effects , Humans
6.
J Allergy Clin Immunol Pract ; 7(8): 2594-2602, 2019.
Article in English | MEDLINE | ID: mdl-31170540

ABSTRACT

BACKGROUND: Allergic condition management more often requires allergist guidance than allergy testing; necessary testing may be unavailable at initial drug allergy consultations. Electronic consultations (e-consults) provide expedited, problem-focused, potentially cost-saving care in other medical specialties, but have not yet been studied in Allergy/Immunology. OBJECTIVE: To describe e-consult use at an academic allergy/immunology practice. METHODS: E-consult data (August 10, 2016 through July 31, 2018) and in-person consult data (August 1, 2014 through July 31, 2018) were reviewed to determine consult volume, outcomes, indications, and timing. Referral reasons and wait times were compared with chi-square tests. RESULTS: E-consults grew from 1% to 10% of all new consults, with concurrent growth in in-person consults. Of 306 completed e-consults, 41 (13.4%) made diagnostic, therapeutic, or alternative referral recommendations, with 30 (73%) recommendations followed; 183 (59.8%) patients required an in-person Allergy/Immunology consult, and only 5 (<2%) patients saw an allergist without an e-consult recommendation to do so. E-consults were used more often than in-person consults for adverse drug reactions (66% vs 9%; P < .001), especially penicillin allergy (132, 61% of all e-consults) and immunodeficiency (15% vs 2%; P < .001). Allergists completed e-consults in a median of 11 minutes, with a median turnaround time of 22 hours. E-consult implementation was associated with a decreased median in-person consult wait time (1.5 fewer calendar days; P < .05). CONCLUSIONS: E-consults were increasingly used, particularly for historical adverse drug reactions and immunodeficiency. Implementation of an e-consult program resulted in decreased in-person wait times despite an increase in overall consult volume, supporting this model's ability to provide expedited, problem-focused care.


Subject(s)
Drug Hypersensitivity/diagnosis , Electronics, Medical/methods , Referral and Consultation/statistics & numerical data , Telemedicine/methods , Allergens/immunology , Allergy and Immunology , Drug Hypersensitivity/epidemiology , Drug Hypersensitivity/therapy , Humans , Penicillins/immunology , Practice Guidelines as Topic , United States/epidemiology
7.
Theranostics ; 8(18): 5126-5142, 2018.
Article in English | MEDLINE | ID: mdl-30429890

ABSTRACT

In ultrasound molecular imaging (USMI), ligand-functionalized microbubbles (MBs) are used to visualize vascular endothelial targets. Netrin-1 is upregulated in 60% of metastatic breast cancers and promotes tumor progression. A novel netrin-1 interference therapy requires the assessment of netrin-1 expression prior to treatment. In this study, we studied netrin-1 as a target for USMI and its potential as a companion diagnostic in breast cancer models. Methods: To verify netrin-1 expression and localization, an in vivo immuno-localization approach was applied, in which anti-netrin-1 antibody was injected into living mice 24 h before tumor collection, and revealed with secondary fluorescent antibody for immunofluorescence analysis. Netrin-1 interactions with the cell surface were studied by flow cytometry. Netrin-1-targeted MBs were prepared using MicroMarker Target-Ready (VisualSonics), and validated in in vitro binding assays in static conditions or in a flow chamber using purified netrin-1 protein or netrin-1-expressing cancer cells. In vivo USMI of netrin-1 was validated in nude mice bearing human netrin-1-positive SKBR7 tumors or weakly netrin-1-expressing MDA-MB-231 tumors using the Vevo 2100 small animal imaging device (VisualSonics). USMI feasibility was further tested in transgenic murine FVB/N Tg(MMTV/PyMT634Mul) (MMTV-PyMT) mammary tumors. Results: Netrin-1 co-localized with endothelial CD31 in netrin-1-positive breast tumors. Netrin-1 binding to the surface of endothelial HUVEC and cancer cells was partially mediated by heparan sulfate proteoglycans. MBs targeted with humanized monoclonal anti-netrin-1 antibody bound to netrin-1-expressing cancer cells in static and dynamic conditions. USMI signal was significantly increased with anti-netrin-1 MBs in human SKBR7 breast tumors and transgenic murine MMTV-PyMT mammary tumors compared to signals recorded with either isotype control MBs or after blocking of netrin-1 with humanized monoclonal anti-netrin-1 antibody. In weakly netrin-1-expressing human tumors and normal mammary glands, no difference in imaging signal was observed with anti-netrin-1- and isotype control MBs. Ex vivo analysis confirmed netrin-1 expression in MMTV-PyMT tumors. Conclusions: These results show that USMI allowed reliable detection of netrin-1 on the endothelium of netrin-1-positive human and murine tumors. Significant differences in USMI signal for netrin-1 reflected the significant differences in netrin-1 mRNA & protein expression observed between different breast tumor models. The imaging approach was non-invasive and safe, and provided the netrin-1 expression status in near real-time. Thus, USMI of netrin-1 has the potential to become a companion diagnostic for the stratification of patients for netrin-1 interference therapy in future clinical trials.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/therapy , Immunotherapy/methods , Molecular Imaging/methods , Molecular Targeted Therapy/methods , Netrin-1/analysis , Ultrasonography/methods , Animals , Antibodies/administration & dosage , Breast Neoplasms/pathology , Disease Models, Animal , Female , Fluorescent Antibody Technique , Heterografts , Humans , Mice, Nude , Mice, Transgenic , Microbubbles , Neoplasm Transplantation , Netrin-1/antagonists & inhibitors , Treatment Outcome
8.
Sci Rep ; 5: 16354, 2015 Nov 18.
Article in English | MEDLINE | ID: mdl-26578234

ABSTRACT

Ultrasound (US) is a non-ionizing pressure wave that can produce mechanical and thermal effects. Bisphosphonates have demonstrated clinical utility in bone metastases treatment. Preclinical studies suggest that bisphosphonates have anticancer activity. However, bisphosphonates exhibit a high affinity for bone mineral, which reduces their bioavailability for tumor cells. Ultrasound has been shown to be effective for drug delivery but in interaction with gas bubbles or encapsulated drugs. We examined the effects of a clinically relevant dose of bisphosphonate zoledronate (ZOL) in combination with US. In a bone metastasis model, mice treated with ZOL+US had osteolytic lesions that were 58% smaller than those of ZOL-treated animals as well as a reduced skeletal tumor burden. In a model of primary tumors, ZOL+US treatment reduced by 42% the tumor volume, compared with ZOL-treated animals. Using a fluorescent bisphosphonate, we demonstrated that US forced the release of bisphosphonate from the bone surface, enabling a continuous impregnation of the bone marrow. Additionally, US forced the penetration of ZOL within tumors, as demonstrated by the intratumoral accumulation of unprenylated Rap1A, a surrogate marker of ZOL antitumor activity. Our findings made US a promising modality to trigger bisphosphonate anticancer activity in bone metastases and in primary tumors.


Subject(s)
Bone Density Conservation Agents/pharmacology , Bone Neoplasms/secondary , Breast Neoplasms/pathology , Diphosphonates/pharmacology , Hyperthermia, Induced , Ultrasonic Waves , Animals , Bone Density Conservation Agents/pharmacokinetics , Bone Neoplasms/metabolism , Bone Neoplasms/therapy , Breast Neoplasms/metabolism , Breast Neoplasms/therapy , Cell Line, Tumor , Cell Survival/drug effects , Cell Survival/radiation effects , Diphosphonates/pharmacokinetics , Disease Models, Animal , Female , Hemiterpenes/biosynthesis , Humans , Hyperthermia, Induced/methods , Imidazoles/pharmacology , Organophosphorus Compounds , Xenograft Model Antitumor Assays , Zoledronic Acid , rap1 GTP-Binding Proteins/metabolism
9.
Ultrasound Med Biol ; 41(10): 2740-54, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26213291

ABSTRACT

Ultrasound-mediated drug delivery is a field of research with promising results, although the exact mechanisms underlying intracellular delivery of therapeutic compounds remain to be elucidated. Many studies use drug carriers and cavitation to enhance drug uptake into tumor cells. However, cavitation could induce cell lysis and remain difficult to control and predict in vivo. In this study, low-intensity ultrasound was delivered using two transducers working at 2.9 and 1.3 MHz. The maximal peak negative pressure was 0.29 MPa to avoid cavitation. Low-intensity ultrasound induced clathrin-mediated endocytosis and forced the penetration of a bisphosphonate (zoledronic acid) into MCF-7 human breast cancer cells potentially as a result of mechanical stresses. When sonication parameters were adjusted to create mild hyperthermia in addition to the mechanical stress, further significant accumulation of ZOL was observed. These results provide better insight into the role of acoustic parameters in drug uptake.


Subject(s)
Clathrin/metabolism , Diphosphonates/administration & dosage , Diphosphonates/pharmacokinetics , Electrochemotherapy/methods , Endocytosis/radiation effects , Imidazoles/administration & dosage , Imidazoles/pharmacokinetics , Sonication/methods , Bone Density Conservation Agents/administration & dosage , Bone Density Conservation Agents/pharmacokinetics , Drug Synergism , Humans , MCF-7 Cells , Radiation Dosage , Zoledronic Acid
10.
Ultrasound Med Biol ; 41(4): 1008-19, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25701522

ABSTRACT

A sonoporation device dedicated to the adherent cell monolayer has been implemented with a regulation process allowing the real-time monitoring and control of inertial cavitation activity. Use of the cavitation-regulated device revealed first that adherent cell sonoporation efficiency is related to inertial cavitation activity, without inducing additional cell mortality. Reproducibility is enhanced for the highest sonoporation rates (up to 17%); sonoporation efficiency can reach 26% when advantage is taken of the standing wave acoustic configuration by applying a frequency sweep with ultrasound frequency tuned to the modal acoustic modes of the cavity. This device allows sonoporation of adherent and suspended cells, and the use of regulation allows some environmental parameters such as the temperature of the medium to be overcome, resulting in the possibility of cell sonoporation even at ambient temperature.


Subject(s)
Cell Membrane Permeability , Ultrasonics/methods , Cells, Cultured , Humans , Reproducibility of Results
12.
J Drug Target ; 22(8): 688-97, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24725154

ABSTRACT

The combination of liposomal doxorubicin (DXR) and confocal ultrasound (US) was investigated for the enhancement of drug delivery in a rat tumour model. The liposomes, based on the unsaturated phospholipid dierucoylphosphocholine, were designed to be stable during blood circulation in order to maximize accumulation in tumour tissue and to release drug content upon US stimulation. A confocal US setup was developed for delivering inertial cavitation to tumours in a well-controlled and reproducible manner. In vitro studies confirm drug release from liposomes as a function of inertial cavitation dose, while in vivo pharmacokinetic studies show long blood circulation times and peak tumour accumulation at 24-48 h post intravenous administration. Animals injected 6 mg kg(-1) liposomal DXR exposed to US treatment 48 h after administration show significant tumour growth delay compared to control groups. A liposomal DXR dose of 3 mg kg(-1), however, did not induce any significant therapeutic response. This study demonstrates that inertial cavitation can be generated in such a fashion as to disrupt drug carrying liposomes which have accumulated in the tumour, and thereby increase therapeutic effect with a minimum direct effect on the tissue. Such an approach is an important step towards a therapeutic application of cavitation-induced drug delivery and reduced chemotherapy toxicity.


Subject(s)
Doxorubicin/therapeutic use , Liposomes/chemistry , Neoplasms, Experimental/diagnostic imaging , Neoplasms, Experimental/drug therapy , Ultrasonic Therapy/methods , Animals , Antibiotics, Antineoplastic/chemistry , Antibiotics, Antineoplastic/therapeutic use , Dose-Response Relationship, Drug , Doxorubicin/blood , Doxorubicin/chemistry , Doxorubicin/pharmacokinetics , Drug Delivery Systems/methods , Random Allocation , Rats , Ultrasonography
13.
Ultrasound Med Biol ; 39(12): 2342-50, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24246245

ABSTRACT

This work examines the use of lanthanide-based contrast agents and magnetic resonance imaging in monitoring liposomal behavior in vivo. Dysprosium (Dy) and gadolinium (Gd) chelates, Dy-diethylenetriaminepentaacetic acid bismethylamide (Dy-DTPA-BMA) and Gd-DTPA-BMA, were encapsulated in pegylated distearoylphosphatidylethanolamine-based (saturated) liposomes, and then intravenously injected into Copenhagen rats with subcutaneous Dunning AT2 xenografts. Liposome-encapsulated Dy chelate shortens transverse relaxation times (T(2) and T(2)*) of tissue; thus, liposomal accumulation in the tumor can be monitored by observing the decrease in T(2)* relaxation time over time. The tumor was treated at the time of maximum liposomal accumulation (48 h) with confocal, cavitating high-intensity focused ultrasound to induce liposomal payload release. Using liposome-encapsulated Gd chelate at high enough concentrations and saturated liposomal phospholipids induces an exchange-limited longitudinal (T(1)) relaxation when the liposomes are intact; when the liposomes are released, exchange limitation is relieved, thus allowing in vivo observation of payload release as a decrease in tumor T(1).


Subject(s)
Gadolinium DTPA , High-Intensity Focused Ultrasound Ablation/methods , Liposomes/radiation effects , Magnetic Resonance Imaging/methods , Organometallic Compounds , Pentetic Acid/analogs & derivatives , Prostatic Neoplasms/pathology , Prostatic Neoplasms/therapy , Animals , Cell Line, Tumor , Contrast Media , Delayed-Action Preparations/radiation effects , Follow-Up Studies , Male , Rats , Reproducibility of Results , Sensitivity and Specificity , Treatment Outcome
14.
Phys Med Biol ; 57(15): 4805-25, 2012 Aug 07.
Article in English | MEDLINE | ID: mdl-22772091

ABSTRACT

High intensity focused ultrasound (HIFU) under MRI guidance may provide minimally invasive treatment for localized prostate cancer. In this study, ex vivo and in vivo experiments were performed using a prostate-dedicated endorectal phased array (16 circular elements arranged on a truncated spherical cap of radius 60 mm) and a translation-rotation mechanical actuator in order to evaluate the lesion formation and the potential interest of dual-modality (electronic and mechanical) interleaved displacement of the focus for volumetric sonication paradigms. Different sonication sequences, including elementary lesions, line scan, slice sweeping and volume sonications, were investigated with a clinical 1.5 T MR scanner. Two orthogonal planes (axial and sagittal) were simultaneously monitored using rapid MR thermometry (PRFS method) and the temperature and thermal dose maps were displayed in real time. No RF interferences were detected in MR acquisition during sonications. The shape of the thermal lesions in vivo was examined at day 5 post-treatment by MRI follow-up (T2w sequence and Gd-T1w-TFE) and postmortem histological analysis. This study suggests that electronic displacement of the focus (along the ultrasound propagation axis) interleaved with mechanical X-Z translations and rotation around B(0) can be a suitable modality to treat patient-specific sizes and shapes of a pathologic tissue. The electronic displacement of focus (achieved in less than 0.1 s) is an order of magnitude faster than the mechanical motion of the HIFU device (1 s latency). As an example, for an in vivo volumetric sonication with foci between 32 and 47 mm (7 successive line scans, 11 lines/slice, 4 foci/line) with applied powers between 17.4 and 39.1 Wac, a total duration of sonication of 408.1 s was required to ablate a volume of approximately 5.7 cm(3) (semi-chronic lesion measured at day 5), while the maximum temperature elevation reached was 30 °C. While electronic focusing is necessary to speed up the procedure, one should consider as a potential drawback the non-negligible risk for generating secondary lobes with full steering in 3D. Reference-free PRFS thermometry accurately removed the effects of B(o) dynamic perturbation in the vicinity of the moving transducer. Therefore, the dual-modality volumetric sonication paradigm represents a cost-effective technological compromise to induce the desired shape of the lesion in the prostate through the limited endorectal space, in a reasonable period of time and without side effects.


Subject(s)
Electrical Equipment and Supplies , Magnetic Resonance Imaging , Mechanical Phenomena , Prostatic Neoplasms/surgery , Sonication/instrumentation , Surgery, Computer-Assisted/instrumentation , Ultrasound, High-Intensity Focused, Transrectal/instrumentation , Animals , Cost-Benefit Analysis , Female , Humans , Male , Precision Medicine , Rabbits , Transducers , Ultrasound, High-Intensity Focused, Transrectal/economics
15.
J Drug Target ; 20(8): 691-702, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22845841

ABSTRACT

BACKGROUND: Targeted and triggered release of liposomal drug using heat or ultrasound represents a promising treatment modality able to increase the therapeutic-totoxicity ratio of encapsulated drugs. PURPOSE: To study the ability for high-intensity focused ultrasound to induce liposomal drug release mainly by focused inertial cavitation in vitro and in an animal model. METHODS: A 1 MHz ultrasound setup has been developed for in vitro and in vivo drug release from a specific liposomal doxorubicin formulation at a target cavitation dose. RESULTS: Controlled cavitation at 1 MHz was applied within the tumors 48 hours after liposome injection according to preliminary pharmacokinetic study. A small non-significant therapeutic effect of US-liposomal treatment was observed compared to liposomes alone suggesting no beneficial effect of ultrasound in the current setup. CONCLUSION: The in vitro study provided a suitable ultrasound setup for delivering a cavitation dose appropriate for safe liposomal drug release. However, when converting to an in vivo model, no therapeutic benefit was observed. This may be due to a number of reasons, one of which may be the difficulty in converting in vitro findings to an in vivo model. In light of these findings, we discuss important design features for future studies.


Subject(s)
Doxorubicin/pharmacology , Doxorubicin/pharmacokinetics , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/metabolism , Animals , Disease Models, Animal , Drug Delivery Systems/methods , Feasibility Studies , Rats , Ultrasonics/methods
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