The effect of ultrasound on the ability to open cell membranes to allow the passage of treatment agents such as drugs and genes has been explored, but the correlation between sonoporation and acoustical cavitation has yet to be observed.  This paper demonstrates the first such correlation by examining an individual cell and the cell membrane poration under the influence of focused ultrasound induced cavitation.

Dynamics of Sonoporation Correlated with Acoustic Cavitation Activities, Yun Zhou, Jianmin Cui, el. al.; Biophysical Journal-Biophysical Letters; doi:10.1529/biophysj.107.125617

Researchers at Tel-Aviv University demonstrated a method of determining, without a contrast agent, which tissue has been thermally coagulated with HIFU using MR imaging.  Contrast agents are typically used in an MRgFUS treatment to determine if the area treated has been sufficiently exposed.  However, once the contrast agent is applied, no further treatment with HIFU is recommended until the agent has cleared the patient’s system.

A technique which uses a magnetization exchange imaging (MEXI) pulse sequence is able to track the transfer of magnetization from water to protein.  Given that coagulated tissue has a faster exchange rate than untreated tissue, it’s possible to define the tissue that was treated during a FUS treatment.  This, in conjunction with the real time thermal feedback that MRI can provide, could lead to verification within the treatment session of accurate tissue treatment.

A new MRI method, tested in vitro for the assessment of thermal coagulation and demonstrated in vivo on focused ultrasound ablation. Carasso D, Hanannel A, Navon G.; NMR Biomed  

NICE, the medical rationing body of the UK, recently announced they are considering reversing their decision to recommend HIFU for patients with prostate cancer to be fully covered through the NHS.

The final decision, set to be made by February, states that HIFU treatments “are not recommended for men with localised or locally advanced prostate cancer other than in the context of controlled clinical trials”.

A Nice spokeswoman said the Hifu procedure was “not cost-effective”. She said: “It’s not about affordability, it’s about value for money. It’s better to spend the money on treatments that you know are clinically effective, that are best value for money and give the best improvement in the patient.”

There has been a lot of backlash against this proposal by NICE with physicians claiming that patients will be denied one of the most promising new technologies available to victims of prostate cancer.

Said Mark Emberton, a urologist at University College Hospital in London, “The cost-effective argument is ludicrous, the economic argument is completely fallacious. We’ve turned a five-day hospital stay into a five-hour hospital stay. All you’re doing is investing in a bit of software and ultrasound kit.”

Several articles and editorials on this decision can be found at the following links:
NHS U-turn on prostate cancer treatment
Ultrasound treatment ruling ‘puts prostate research back years’
Cancer treatment decision warning
Men must be champions of prostate breakthrough

InSightec announced that they have received approval from the FDA to begin a phase 3 trial of their ExAblate MRgFUS device to determine if it can reduce the pain caused by bone metastases safely and effectively in patients who have failed to respond to radiation therapy.

“Pain from tumors that have spread to the bone is the most common kind of pain for cancer patients,” notes Dr. Mark Hurwitz of the Dana-Farber/Brigham & Women’s Cancer Center at Harvard Medical School and President-Elect of the Society for Thermal Medicine. “While maintaining quality of life for patients with advanced cancer is a top priority, current palliative treatments have several limitations. When pain persists or recurs after palliative radiation, options are often limited as, many patients are too weak to withstand invasive procedures to quell their pain. The ExAblate treatment has shown promising efficacy and safety results in feasibility studies. We look forward to participating in this pivotal study which could provide us with a non-invasive and effective way to improve late-stage cancer patients’ quality of life.”  

The Department of Obstetrics and Gynecology at Duke University has recently opened its MRgFUS treatment facility for the treatment of uterine fibroids.

One of the significant aspects of this clinic is that it is the first opened by an OB/GYN department instead of a radiology department.

For more information and contact info, contact the Duke OB/GYN department.

InSightec, makers of the MRgFUS ExAblate system, announced that the World Economic Forum has selected the company as one of its Technology Pioneers for 2008. Technology Pioneers are companies developing and applying technologies deemed highly transformational and innovative in the areas of energy, biotechnology and health and information technology. The World Economic Forum appointed a panel of leading technology experts to select the finalists from a pool of 273 nominees.

“We believe this non-invasive technology has the potential to become one of the major forms of surgery within the next 20 years, helping improve millions of lives without the long hospitalizations, extended recovery times, side effects, complication risks and extensive costs associated with invasive surgery,” said Dr. Kobi Vortman, InSightec’s President and CEO.

The NIH has initiated a new grant to fund research in innovative ultrasound therapy technologies, including high intensity focused ultrasound.

“The primary goal of this initiative is to develop and accelerate the implementation of innovative, disruptive, non-invasive or minimally invasive ultrasound technologies that produce or enhance interventional therapies in humans. Research projects must focus on the solution of critical basic and/or technical problems that presently exist, and that have previously prevented these technologies from being implemented as safe and effective clinical therapies in humans.

This initiative is for a five-year award for applicant organizations that propose to develop disruptive ultrasound technologies that lead to implementation of safe and effective therapies. A disruptive technology is one that displaces existing dominant technology, due to its clear advantage(s) over previous technologies. This initiative encourages multidisciplinary collaborations and partnerships with industry.”

Total funding for the grants is anticipated to be approximatelly $5 million with up to 10 research proposals receiving funding in FY 2008. Application deadline for the grant is January 23rd, 2008.

InSightec, maker of the MRgFUS ExAblate system, announced that it has closed an internal round of additional financing of $30 million from existing investors including Elbit Imaging LLC, GE Capital Equity Holdings Inc. and MediTech Advisors LLC. 

Said InSightec CEO Kobi Vortman, “The investment will allow acceleration of the technical and clinical research for oncology applications,” such as bone metastases, prostate cancer, breast cancer, liver tumors and brain tumors.

The BBC News website featured the HIFU application of using inertial cavitation to assist in the treatment of tumors. 

Said Dr. Coussios, of Oxford’s Biomedical Ultrasonics and Biotherapy Laboratory (BUBL), ”If we can use cavitation to accelerate the treatment, better localise the treatment - meaning that you will never get pre-focal damage - deliver the treatment at a lower frequency so you can go deeper in the body, and if we can also use these bubbles to monitor the treatment in real time, we have solved all the major limitations of Hifu in one go.”

This article presents the results of using a 300 element phased array ultrasound source to focus ultrasound beams on a target located behind excised sheep ribs in situ and transcranially in vivo with a monkey subject.  The method used to target through the ribs involves using the HIFU array to operate in a transmit and a receive mode.  The echographic image generated from the reflection of the ultrasound waves is used to first construct the model of the ribcage which is then used to selectively active or deactivate the transducers to avoid the heating of the ribs.

For the transcranial application, the acoustical properties of the skull were first calculated from CT scan data and the ultrasound plan adjusted based on how the skull would attenuate the ultrasound beams.

High power phased array prototype for clinical high intensity focused ultrasound : applications to transcostal and transcranial therapy.  Conference Proceedings of the IEEE Engineering in Medicine and Biology Society. 2007;1:234-7