A new imaging technique that pin-points the exact location and size of prostate cancer could help hundreds of thousands of men worldwide. Other types of cancer could also be targeted.
The technique combines two existing imaging technologies, computed tomography (CT) and magnetic resonance imaging (MRI), to target radiotherapy to the cancer cells and not surrounding healthy tissue.
CT scans are used to plan radiotherapy for most cancers, as the bone structure is easily visible. “The problem with CT, though, is that it doesn’t give us detail of the soft tissues,” says Peter Hoskins from Mount Vernon Hospital in Middlesex. All radiotherapists see is a “blob”.
On the other hand, MRI can define tumours and soft tissue very clearly, but is less good at revealing the bone position. This means there is no “map” for use on directing the radiation.
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The software developed at King’s College London and the Royal Marsden Hospital now allows the soft tissue information to be transposed from the MRI to the CT scan.
They plan to use this composite imaging in applying brachytherapy, where a series of radiation sources are focused directly into the walnut-sized prostate gland.
Radiotherapists must treat the entire tumour, but do not want to irradiate healthy tissue. Side-effects of such damage include diarrhoea, impotence and incontinence. But Hoskins says that with current scanning techniques “you’re very hard-pressed to know where the line between the rectum and prostate is”.
The new imaging technique is expected to be validated later in 2001. The team believes it could avoid normal tissue damage in any cancer where MRI currently gives better images than CT scanning, such as brain tumours.
![Astronomers have long known that understanding how star clusters come to be is key to unlocking other secrets of galactic evolution. Stars form in clusters, created when clouds of gas collapse under gravity. As more and more stars are born in a collapsing cloud, strong stellar winds, harsh ultraviolet radiation and the supernova explosions of massive stars eventually disperse the cloud, and their light can bear down on other star-forming regions in the galaxy. This process is called stellar feedback, and it means that most of the gas in a galaxy never gets used for star formation. Researching how star clusters develop can answer questions about star formation at a galactic scale. Now, the state of the art has been further developed with both Hubble and Webb working together to provide a broad-spectrum view of thousands of young star clusters. An international team of astronomers has pored over images of four nearby galaxies from the FEAST observing programme (#1783), trying to solve this mystery. Their results show that it is the most massive star clusters that clear away their gaseous shroud the fastest, and begin lighting their galaxy the earliest. The team identified nearly 9000 star clusters in the four galaxies in different evolutionary stages: young clusters just starting to emerge from their natal clouds of gas, clusters that had partially dispersed the gas (both from Webb images), and fully unobstructed clusters visible in optical light (found in Hubble images). With Webb???s ability to peer inside the gas clouds, they were able to then estimate the mass and age of each cluster from its light spectrum. This image shows a section of one of the spiral arms of Messier 51 (M51), one of the four galaxies studied in this work, as seen by Webb???s Near-Infrared Camera (NIRCam). The thick clumps of star-forming gas are shown here in red and orange, representing infrared light emitted by ionised gas, dust grains, and complex molecules such as polycyclic aromatic hydrocarbons (PAHs). Within these gas complexes, each tens or hundreds of light years across, Webb reveals the dense, extremely bright clusters of massive stars that have just recently formed. The countless stars strewn across the arm of the galaxy, many of which would be invisible to our eyes behind layers of dust, are also laid bare in infrared light. [Image description: A large, long portion of one of the spiral arms in galaxy M51. Red-orange, clumpy filaments of gas and dust that stretch in a chain from left to right comprise the arm. Shining cyan bubbles light up parts of the gas clouds from within, and gaps expose bright star clusters in these bubbles as glowing white dots. The whole image is dotted with small stars. A faint blue glow around the arm colours the otherwise dark background.]](https://images.newscientist.com/wp-content/uploads/2026/05/13114322/SEI_296271016.jpg)
