MR image stack enhances brain surgery safety
Researchers at Prism Clinical Imaging (Elm Grove, WI) and the Medical College of Wisconsin (Milwaukee, WI) have bagged a $1.6 million, three-year grant from the National Institutes of Health to develop imaging software for use in brain-cancer treatments. "This project will allow us to refine and validate new methods for mapping brain function with MRI and for displaying the results in an intuitive format that greatly simplifies interpretation by the physician," explained principal investigator Edgar DeYoe, professor of radiology and a Prism co-founder.
The software provides anatomical, functional and physiological image sequences in a single integrated view, referred to as a stack. A new type of display – a functional field map – shows what the brain images mean for the patient's vision and movement abilities. This function allows surgeons to identify areas of the patient's brain that may be essential for movement, vision and other functions, and avoid these during tumour removal.
CyberKnife targets early-stage lung cancer
Treatment of early-stage, non-small cell lung cancer with radical stereotactic radiosurgery using the Accuray CyberKnife can result in 100% three-year survival, in patients with good lung function. In a study of 24 patients treated with the CyberKnife, the overall survival for all subjects was 79% at an average follow-up of 36 months. Five deaths occurred due to progressive lung dysfunction. For patients with better pre-treatment lung function, survival was 100%.
"Our goal has been to find a reasonable option for patients who don't want or can't tolerate surgery," said lead author Brian T Collins, a radiation oncologist with the Georgetown Lombardi Comprehensive Cancer Center (Washington, DC). "What we discovered is a very promising option that may be relevant for other stage-one patients as well. More follow up with these patients is planned to see how they progress five years after treatment." Collins presented the results at the annual CHEST meeting, held earlier this month in San Diego, CA.
HYPERImage team advances PET/MR
The HYPERImage research project, an EU-funded consortium of eight partners from six European countries, has taken a major step forward in its goal to create a hybrid PET/MR system. The work was revealed at last month's IEEE Nuclear Science Symposium and Medical Imaging Conference in Orlando, FL.
Creating a hybrid PET/MR requires two key developments: an MR-compatible PET detector, plus a method of accounting for PET attenuation. According to project leader Royal Philips Electronics, the HYPERImage team has now come up with a functional gamma-ray detector that meets the performance requirements of the latest time-of-flight PET scanners and is compatible with the strong magnetic fields that would be present in a PET/MR scanner. The team has also achieved major progress with respect to MRI-based static and dynamic PET attenuation correction.
Real-time OCT identifies surgical margins
A study of intraoperative optical coherence tomography (OCT) has demonstrated that the technique can effectively evaluate surgical margins during lumpectomy. The investigation, headed up at the University of Illinois at Urbana-Champaign (Urbana, IL), examined 37 patients divided into a training set (17) and a study set (20). In the study set, intraoperative OCT had 100% sensitivity and 82% specificity for determining margin status, using postoperative histopathology as the gold standard (Cancer Res. 69 8790).
OCT offers an imaging resolution of around 10 µm and imaging depths of up to 2 mm into tissue. Image features can also be used to identify structures such as surface blood or cauterized tissue, and distinguish these from normal and tumour tissue. The researchers are now working on computer-aided detection algorithms that can automatically identify suspicious areas within images, and developing techniques to improve imaging resolution over larger volumes of tissue.
Proton boost reduces prostate cancer recurrence
A high-dose boost of proton therapy after a standard course of X-ray radiotherapy can reduce the recurrence of prostate cancer, according to research presented earlier this month at the ASTRO Annual Meeting in Chicago, IL. In a study at Loma Linda University Medical Center (Loma Linda, CA) and Massachusetts General Hospital (Boston, MA), 391 patients with early prostate cancer were randomized to receive a boost to the prostate using conformal protons of either 19.8 or 28.8 GyE.
In patients with low-risk disease, only 6% of those treated with the high-dose regime (total dose of 79.2 GyE) experienced recurrence after 10 years, compared to 29% of those who received a conventional radiation dose (70.2 GyE). A similar trend was seen in intermediate-risk patients. There were no significant differences between the groups in overall survival or in urinary and bowel functions. "There is a lot of interest in proton therapy for prostate cancer," said Carl J Rossi Jr, a Loma Linda radiation oncologist. "This study proves the importance of giving high radiation doses to prostate-cancer patients with low- and intermediate-risk disease, because it demonstrates that even these 'favourable' patients still benefit from the extra high-dose treatment."
IBM Research unveils diagnostic chip
Scientists at IBM Research – Zurich, working in collaboration with the University Hospital of Basel in Switzerland, have developed a diagnostic test that uses capillary forces to analyse tiny samples of serum or blood for the presence of various disease markers. The silicon-chip-based device is said to require less sample volume, and be significantly faster, than traditional tests. The 1 × 5 cm microfluidic chip contains sets of micron-wide channels through which the test sample flows in around 15 s (Lab Chip 9 3330).
To perform the test, a 1 µl sample is placed on the chip, where capillary forces begin to take effect and push the sample through a series of mesh structures. The sample reaches a region containing small amounts of detection antibodies. These fluorescently tagged antibodies recognize and attach to disease markers within the sample. Finally, the sample reaches a 30 x 20 µm reaction chamber, where the tagged disease marker is captured and viewed via fluorescence imaging. The entire process is driven by a miniature capillary pump that pumps the sample through the device.
PET predicts treatment response
PET-CT performed after the completion of chemoradiotherapy for head-and-neck cancer is a valuable tool for measuring treatment response, according to a study led by James P Malone of the Southern Illinois School of Medicine (Springfield, IL). Malone and colleagues analysed 31 patients with advanced-stage head-and-neck cancer. All patients underwent PET/CT scanning six to eight weeks after completion of treatment and were then tracked for a median of 24 months (Arch. Otolaryngol. Head Neck Surg. 135 1119).
Assessment of tumour response at the primary site with PET-CT had a sensitivity of 83%, a specificity of 54%, a positive predictive value of 31% and a negative predictive value of 92%. In the 21 patients whose disease had spread to surrounding lymph nodes before treatment, sensitivity was 75%; specificity, more than 94%; positive predictive value, more than 75%; and negative predictive value, 94%. For the 10 whose cancer was located in the neck only, specificity was 92% and negative predictive value more than