MR-guided HIFU enables non-invasive neurosurgery
High-intensity focused ultrasound (HIFU) has been used for some years to treat uterine fibroids and prostate gland tumours. However, HIFU treatment of the brain through the intact skull has proved technically challenging. Now, the Magnetic Resonance Center of the University Children's Hospital Zurich, Switzerland, has achieved a world first by successfully using transcranial MR-guided HIFU for non-invasive brain surgery. Since September 2008, ten patients have been treated with this procedure in the context of a clinical study. All interventions were completed successfully and without complications.
The prototype treatment system combined the ExAblate 4000, developed by InSightec of Israel, with a 3T MR-scanner from GE. Ultrasound beams produced by 1024 transducers are transferred through the patient's intact skull into the brain and focused to a diameter of 3-4 mm, enabling coagulation of sharply defined targets deep inside the brain. The entire surgical procedure, which lasts several hours and is performed without anaesthesia, is planned and monitored in real time by MR imaging.
Low-level light therapy benefits Parkinson's disease
Research from the University of Virginia Health System (Charlottesville, VA) reveals that low-level light therapy (LLLT) holds potential for improving neuronal cell function in patients with Parkinson's disease. The in vitro study showed that a single, brief treatment with 810 nm low-level laser light increased (for two-hours) the velocity of mitochondrial movement in cells taken from patients with sporadic Parkinson's disease. The movement increased to levels comparable to cells from a disease-free, age-matched control group. The therapy had no impact on healthy control group cells (Mol. Neurodegener. 4 26).
"Our findings provide early-stage confirmation that LLLT has the potential to improve neuronal function in many patients with Parkinson's disease and other neurological diseases," said Patricia A. Trimmer, associate professor of neurological research at the University of Virginia School of Medicine. Trimmer points out that numerous investigational Parkinson's disease drugs have demonstrated efficacy in animal models but proven largely ineffective in humans. In contrast, LLLT is already being used to treat a wide range of human conditions.
Oxygen and MRI predicts cancer therapy success
A simple MRI test could help oncologists determine the best treatment for some cancer patients, according to a study from UT Southwestern Medical Center (Dallas, TX). The researchers used BOLD (blood oxygen level dependent) MRI to detect oxygen levels in tumours without the need for an invasive procedure. This oxygen level can be a predictor of how well a tumour will respond to treatment. "The patient simply inhales pure oxygen, which then circulates through the bloodstream, including to the tumours," said senior author Ralph Mason (Magn. Reson. Med. doi: 10.1002/mrm.22020).
In studies of breast tumours implanted below the skin of rats, BOLD MRI performed as well as the standard procedure (FREDOM, which requires injection of a reporter molecule directly into the tumour) used to gauge tumour oxygenation. UT Southwestern physicians at are already testing BOLD MRI in patients with cervical, prostate and head-and-neck cancers. The researchers are currently determining how much oxygen a patient must inhale in order to be effective. The next step is to expand patient studies and examine more tumour types.
CT-based colorectal screening shows good accuracy
CT colonography may offer patients with an increased risk of colorectal cancer a less-invasive alternative to colonoscopy, according to a study headed up at the Institute for Cancer Research and Treatment in Turin, Italy. The research team assessed the accuracy of CT colonography in detecting advanced colorectal neoplasia in asymptomatic individuals at increased risk (with a first-degree family history of advanced colorectal neoplasia, a personal history of colorectal adenomas or positive results from faecal occult blood tests), using colonoscopy as the reference standard (JAMA 301 2453).
Each participant in the multicentre study underwent CT colonography followed by colonoscopy on the same day. Overall, CT colonography identified 151 of 177 participants with advanced neoplasia of 6 mm or larger (85.3% sensitivity) and correctly classified results as negative for 667 of 760 participants without such lesions (87.8% specificity). The positive and negative predictive values were 61.9% and 96.3%, respectively. The researchers write that "CT colonography is better accepted than colonoscopy and has a negligible risk of serious adverse events; thus, it may help increase the low adherence reported for individuals who are candidates for screening."
Ultrasonics improve view during neurosurgery
A Norwegian collaboration has developed an ultrasonic instrument that can improve a neurosurgeon's view during surgery to remove tumours from the pituitary gland. The team - from SINTEF, NTNU and St. Olav's Hospital in Trondheim - has used the instrument on 15 patients at St. Olav's Hospital. "We are probably able to remove more tumour tissue than we would have been able to do otherwise, which reduces the chances of the tumour returning, and increases the likelihood of obtaining a nearly normal hormonal balance," said assistant physician and doctoral student Ole Solheim.
"The instrument also makes it easier to see where the tumour cells lie relative to the visual nerves and blood vessels – structures close to the pituitary that we must avoid damaging during the operation," Solheim added, noting that large-scale comparative studies of operations on pituitary-tumour patients are needed before the instrument's value can be documented.
Spectral imaging helps characterize melanoma
The Computer Vision research group at the Universitat Jaume I in Spain, working with the Hospitals Consortium of Castelló, is developing a digital analysis system for multispectral images that could help physicians distinguish melanoma from other skin diseases. The team plans to create a database containing multispectral images of melanomas, and select the multispectral bands for their subsequent study and classification.
The first stage involves analysing dermoscopic images of melanomas and benign lesions to determine whether their distinctive features might be identified by a computer. The second stage includes a dermoscopy during the patient's visit to the dermatologist and spectrographic imaging during visits to oncology surgeons. Both results can then be compared and checked against the pathologic anatomy. The objective is to determine what substances can be applied on the melanoma to facilitate spectral analysis and which multispectral features could help diagnose melanomas.