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magnetic fields cancer

Soumaye Amirsaadat, Younes Pilehvar-Soltanahmadi, Faraz Zarghami, Shahriar Alipour, Zohreh Ebrahimnezhad, Nosratollah Zarghami
Nanoparticle-based targeted drug delivery has the potential for rendering silibinin specifically at the favorite site using an external magnetic field. Also, it can circumvent the pitfalls of poor solubility. For this purpose, silibinin-loaded magnetic nanoparticles are fabricated, characterized and evaluated cytotoxicity and hTERT gene expression in A549 lung cancer cell line. silibinin-loaded PLGA-PEG-Fe3O4 had dose- and time-dependent cytotoxicity than pure silibinin. Additionally, hTERT expression is more efficiently reduced with increasing concentrations of nanosilibinin than pure silibinin...
January 12, 2017: Artificial Cells, Nanomedicine, and Biotechnology
B Liang, G Q Zuo, Y Y Zheng, S He, D Y Zuo
Objective: To prepare the Fe3O4-loaded biodegradable liquid-solid phase inversion poly(lactic-co-glycolic acid) (PLGA) in situ implant for ultrasound-guided injection into nude mouse tumor model, and to investigate its clinical effect in thermomagnetic treatment of nude mice with human liver cancer SMMC-7721 cells in an alternating magnetic field. Methods: An in situ implant containing 10% Fe3O4 was prepared, and 50 μl Fe3O4-PLGA-NMP gel was injected into the subcutaneous tissue of Kunming mice. The degradation of this material was observed for 2 consecutive months, and the changes in body weight were recorded...
December 20, 2016: Zhonghua Gan Zang Bing za Zhi, Zhonghua Ganzangbing Zazhi, Chinese Journal of Hepatology
Islam Reda, Ahmed Shalaby, Mohammed Elmogy, Ahmed Abou Elfotouh, Fahmi Khalifa, Mohamed Abou El-Ghar, Ehsan Hosseini-Asl, Georgy Gimel'farb, Naoufel Werghi, Ayman El-Baz
Early detection of prostate cancer increases chances of patients' survival. Our automated non-invasive system for computer-aided diagnosis (CAD) of prostate cancer segments the prostate on diffusion-weighted magnetic resonance images (DW-MRI) acquired at different b-values, estimates its apparent diffusion coefficients (ADC), and classifies their descriptors - empirical cumulative distribution functions (CDF) - with a trained deep learning network. To segment the prostate, an evolving geometric (level-set-based) deformable model is guided by a speed function depending on intensity attributes extracted from the DW-MRI with nonnegative matrix factorization (NMF)...
December 23, 2016: Computers in Biology and Medicine
Lei Zhang, Xinmiao Ji, Xingxing Yang, Xin Zhang
Increasing evidence shows that static magnetic fields (SMFs) can affect cell proliferation but mixed results have been reported. Here we systematically examined the effects of 1 T (Tesla) SMF, which is close to the SMF intensity that patients are exposed to MRI (magnetic resonance imaging) scanners in hospitals, for its effect on 15 different cell lines, including 12 human and 3 rodent cell lines. Our results show that 1 T SMF does not have apparent impact on cell cycle or cell death. However, at higher cell density, it reduced cell numbers in six out of seven solid human cancer cell lines...
January 4, 2017: Oncotarget
Louis Evelyne, Francois-Xavier Cantrelle, Liesbet Mesotten, Gunter Reekmans, Liene Bervoets, Karolien Vanhove, Michiel Thomeer, Guy Lippens, Peter Adriaensens
Accurate identification and quantification of human plasma metabolites can be challenging in crowded regions of the NMR spectrum with severe signal overlap. Therefore, this study describes metabolite spiking experiments on the basis of which the NMR spectrum can be rationally segmented into well-defined integration regions, and this for spectrometers having magnetic field strengths corresponding to (1) H resonance frequencies of 400 MHz and 900 MHz. Subsequently, the integration data of a case-control dataset of 69 lung cancer patients and 74 controls were used to train a multivariate statistical classification model for both field strengths...
January 6, 2017: Magnetic Resonance in Chemistry: MRC
Balasubramanian Sivakumar, Ravindran Girija Aswathy, Rebeca Romero-Aburto, Trevor Mitcham, Keith A Mitchel, Yutaka Nagaoka, Richard R Bouchard, Pulickel M Ajayan, Toru Maekawa, Dasappan Nair Sakthikumar
We have designed versatile polymeric nanoparticles with cancer cell specific targeting capabilities via aptamer conjugation after the successful encapsulation of curcumin and superparamagnetic iron oxide nanoparticles (SPIONs) inside a PLGA nanocapsule. These targeted nanocomposites were selectively taken up by tumor cells, under in vitro conditions, demonstrating the effectiveness of the aptamer targeting mechanism. Moreover, the nanocomposite potentially functioned as efficient multiprobes for optical, magnetic resonance imaging (MRI) and photoacoustic imaging contrast agents in the field of cancer diagnostics...
January 6, 2017: Biomaterials Science
Nathanael A Stocke, Pallavi Sethi, Amar Jyoti, Ryan Chan, Susanne M Arnold, J Zach Hilt, Meenakshi Upreti
Magnetic hyperthermia as a treatment modality is acquiring increased recognition for loco-regional therapy of primary and metastatic lung malignancies by pulmonary delivery of magnetic nanoparticles (MNP). The unique characteristic of magnetic nanoparticles to induce localized hyperthermia in the presence of an alternating magnetic field (AMF) allows for preferential killing of cells at the tumor site. In this study we demonstrate the effect of hyperthermia induced by low and high dose of MNP under the influence of an AMF using 3D tumor tissue analogs (TTA) representing the micrometastatic, perfusion independent stage of triple negative breast cancer (TNBC) that infiltrates the lungs...
December 23, 2016: Biomaterials
C Toramatsu, T Inaniwa
PURPOSE: In charged particle therapy with pencil beam scanning (PBS), localization of the dose in the Bragg peak makes dose distributions sensitive to lateral tissue heterogeneities. Sensitivity of a PBS plan to lateral tissue heterogeneity can be reduced by selecting suitable beam angles. The purpose of this study is to establish a fast and accurate method of beam angle selection for PBS. METHODS: The lateral tissue heterogeneity surrounding the path of respective pencil beams at a given angle was quantified with the heterogeneity number using effective density data of patients...
June 2016: Medical Physics
T C F van Heijst, N Hoekstra, M E P Philippens, D Eschbach, J J W Lagendijk, H J G D van den Bongard, B van Asselen
PURPOSE: The Utrecht MRI-linac (MRL) design enables new MR-guided radiotherapy (RT) approaches. This is a feasibility study for a single-fraction high dose (boost) to individual lymph nodes (LNs) in breast-cancer patients, after breast-conserving surgery (BCS) and hypofractionated whole-breast irradiation (WBI) with conventional axillary RT (AxRT). METHODS: After written informed consent, 5 breast-cancer patients (cT1-3N0) were enrolled (NL500460.041.14 trial) and underwent 1...
June 2016: Medical Physics
J Park, J Kim, S Park, S Kim, K Shin
PURPOSE: To investigate exposure outside the treatment field when treating breast cancer with tri-Co-60 magnetic resonance (MR) image guided radiation therapy (IGRT) system. METHODS: A total of 7 patients who treated with accelerated partial breast irradiation (APBI) technique were selected prospectively for this study (prescription dose = 38.5 Gy in 10 fractions). Every patient treated with two plans, one was an initial plan and the other was an adaptive plan generated after finishing 5 fractions (a total of 14 plans)...
June 2016: Medical Physics
P Keall, B Dong, P Vial, A Walker, K Zhang, J Begg, R Rai, L Holloway, M Barton, S Crozier, G Liney
PURPOSE: The pursuit of real-time image guided radiotherapy using optimal tissue contrast has seen the development of several hybrid MRI-treatment systems, high field and low field, and inline and perpendicular configurations. As part of a new MRI-Linac program, an MRI scanner was integrated with a linear accelerator to enable investigations of a coupled inline MRI-Linac system. This work describes our experimental results from the first high-field inline MRI-Linac. METHODS: A 1...
June 2016: Medical Physics
S Goddu, G Kamal, A Herman, S Edwards, S Yaddanapudi, S Oddiraju, B Cai, D Rangaraj, S Mutic
PURPOSE: According to TG-40 percent-depth-dose (PDD) tolerance is ±2% but TG-142 is ±1%. Now the question is, which one is relevant in IMRT era? The primary objective of this study is to evaluate dosimetric impact of beam-energy-drifts on IMRT-delivery. METHODS: Beam-energy drifts were simulated by adjusting Linac's bending-magnet-current (BMC) followed by tuning the pulse-forming network and adjusting gun-current. PDD change of -0.6% and +1.2% were tested. Planar-dosimetry measurements were performed using an ionization-chamber-array in solid-water phantoms...
June 2016: Medical Physics
J Yoon, D Heins, R Zhang
PURPOSE: To model the magnetic port in the temporary breast tissue expanders and to improve accuracy of dose calculation in Pinnacle, a commercial treatment planning system (TPS). METHODS: A magnetic port in the tissue expander was modeled with a radiological measurement-basis; we have determined the dimension and the density of the model by film images and ion chamber measurement under the magnetic port, respectively. The model was then evaluated for various field sizes and photon energies by comparing depth dose values calculated by TPS (using our new model) and ion chamber measurement in a water tank...
June 2016: Medical Physics
S Lim-Reinders, B Keller, C McCann, A Sahgal, J Lee, A Kim
PURPOSE: Hypofractionated partial breast irradiation (HPBI) is being used at our clinic to treat inoperable breast cancer patients who have advanced disease. We are investigating how these patients could benefit from being treated in an MRI-linac, where real-time daily MRI tumor imaging and plan adaptation would be possible. As a first step, this study evaluates the dosimetric impact of the magnetic field for different radiation beam geometries on relevant OARs. METHODS: Five patients previously treated using HPBI were selected...
June 2016: Medical Physics
Y Lu, I Chen, R Kashani, H Wan, N Maughan, D Muccigrosso, P Parikh
PURPOSE: In MRI-guided online adaptive radiation therapy, re-contouring of bowel is time-consuming and can impact the overall time of patients on table. The study aims to auto-segment bowel on volumetric MR images by using an interactive multi-region labeling algorithm. METHODS: 5 Patients with locally advanced pancreatic cancer underwent fractionated radiotherapy (18-25 fractions each, total 118 fractions) on an MRI-guided radiation therapy system with a 0.35 Tesla magnet and three Co-60 sources...
June 2016: Medical Physics
S Ahn, N Lee, S Shin, C Choi, Y Han, H Park, D Choi, D Lim
PURPOSE: To investigate the feasibility of using multifunctional Fe3 O4 /TaOx(core / shell) nano particles developed for CT and MRI contrast agent as dose enhancing radiosensitizers. METHODS: Firstly, to verify the imaging detectability of Fe3 O4 /TaOx nano particles, in-vivo tests were conducted. Approximately 600 mg/kg of 19 nm diameter Fe3 O4 /TaOx nano particles dispersed in phosphate buffered saline(PBS) were injected to ten nude Balb/c mice through the tail vein...
June 2016: Medical Physics
G Bolard, S Bulling
PURPOSE: To quantify the effect of MR-only treatment planning on dose distributions for prostate cancer for the clinical validation of MR-only workflow. METHODS: For pre-clinical validation of the MR workflow where five-value stratified synthetic CT (Magnetic Resonance for Calculating Attenuation (MRCAT) algorithm Philips Ingenia 3.0T) are used for dose calculation instead of CT we (1) converted conventional 12-bit CT scans to five-value stratified CT and (2) applied the measured geometric distortions (deformation vector field measured with a dedicated phantom) from the MR scanner to the CT scans of 10 patients to quantify the effect on dose to target and organs-at-risk (OAR) for IMAT prostate plans...
June 2016: Medical Physics
J Andreozzi, K Mooney, P Bruza, A Curcuru, S Saunders, D Gladstone, B Pogue, O Green
PURPOSE: To investigate the viability of using Cherenkov imaging as a fast and robust method for quality assurance tests in the presence of a magnetic field, where other instruments can be limited. METHODS: Water tank measurements were acquired from a clinically utilized adaptive magnetic resonance image guided radiation therapy (MR-IGRT) machine with three multileaf-collimator equipped 60Co sources. Cherenkov imaging used an intensified charge coupled device (ICCD) camera placed 3...
June 2016: Medical Physics
S Al-Ward, A Kim, C McCann, M Ruschin, P Cheung, A Sahgal, B Keller
PURPOSE: To simulate tumor tracking in an Elekta MRI-linac (MRL) and to compare this tracking method with our current ITV approach in terms of OAR sparing for lung cancer patients. METHODS: Five SABR-NSCLC patients with central lung tumors were selected for reasons of potential enhancement of tumor-tissue delineation using MRI. The Monaco TPS was used to compare the current clinical ITV approach to a simulated, novel tracking method which used a 7MV MRL beam in the presence of an orthogonal 1...
June 2016: Medical Physics
M Kadbi
PURPOSE: Utilization of Titanium Tandem and Ring (T&R) applicators in MR-guided brachytherapy has become widespread for gynecological cancer treatment. However, Titanium causes magnetic field disturbance and susceptibility artifact, which complicate image interpretation. In this study, metal artifact reduction techniques were employed to improve the image quality and reduce the metal related artifacts. METHODS: Several techniques were employed to reduce the metal artifact caused by titanium T&R applicator...
June 2016: Medical Physics
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