Diagnosis of prostate cancer by imaging
Preliminary computerized imaging reveals the shape of the prostate and a compartment within the gland-called the transitional zone-consistently differ in men with prostate cancer than those without the disease, according to new research led by Case Western Reserve University.
The finding may provide a new avenue to diagnose the disease-perhaps even the cancer’s aggressiveness.
The differences held up in comparisons of magnetic resonance imaging (MRI) scans of 70 patients. The scans came from three different medical institutions in Ohio and two in Sydney, Australia, on different makes and models of MRI’s.
‘Looking at shape is a fundamental shift from looking at the intensity of pixels in an image to predict if a patient has prostate cancer,’ said Anant Madabhushi, professor of biomedical engineering and leader of the research. ‘Pixel intensities vary, but shape is resilient.’
Variability in MRI scans can result in disagreement as to whether prostate cancer is present, in turn potentially resulting in unnecessary biopsies and treatments. The American College of Radiology and others are working to develop standards to eliminate inconsistencies in imaging.
To find the differences in shapes, the researchers took images of 35 cancerous prostates, aligned them into a single frame and created a statistical shape atlas. They then took images of 35 healthy prostates, aligned them in one frame and created a second statistical shape atlas.
The researchers then aligned the two frames and controlled for size-tumours and a noncancerous condition, called benign prostatic hyperplasia (which some images in this study showed), increase the gland’s volume.
Comparing cancerous and cancer-free prostates showed clear, statistically significant differences in both the shape of the transitional zone-which is in the central part of the gland-and the gland itself.
The researchers analysed and compared the images from each of the five medical institutions and found that, no matter where the images were from, differences in shapes between cancerous and cancer-free prostates were consistent.
Madabhushi said that if shape proves to be a reliable marker of cancer, it could be combined with radiomics, which employs computer algorithms to extract differentiating features in cancerous and non-cancerous tissues.
Case Western Reserve University http://tinyurl.com/zonynty