A sound and light show

If you've been following mainstream media reports about events at this year's meeting of the American Association for Cancer Research, you might think the most important news has to do with the impact of soy, strawberries and beer on the development of cancer. While editors and news producers may think such stories are appealing to a general audience, they barely touch the breadth and depth of research being presented here.And the conference isn't limited to cutting-edge science--it's also a showcase for state-of-the-art technology.Take, for example, emerging strategies for the early detection of cancer. Today I attended a session that detailed the use of new nanotechnologies, as well as the merging of in vitro (from the Latin for in glass) diagnostics with in vivo (from the Latin for in body) molecular imaging. A rationale, and then a few words about each of these exciting developments:It goes without saying that the earlier cancer can be detected, the sooner it can be diagnosed and treatments can be evaluated. Stanford radiology professor Sanjiv Gambhir explained that magnetic nanotechnology promises to produce an ultrasensitive detector of cancer proteins. How?Magnetism is a fundamental property of all materials. In a magnetically neutral biologic setting, magnetic fields stand out better than fluorescence, the current standard for detecting cancer-related proteins. Find a way to develop a biological marker that produces a magnetic change in targeted cancer proteins, and those cancerous cells will stand out on a magnetic image like a neon light on a dark night. Think of it this way: By introducing just the right magnetic "bait" into the blood or biopsy sample, scientists can "catch" the culprit proteins and know sooner whether a treatment is working.His research group is also working on molecular imaging, including optical, ultrasound and photo acoustics.Gambhir described using photoacoustics to track tumor development. Here's how it works: Aim a laser light pulse at suspect tissue for a fraction of a second, and the tissue heats up, creating a pressure wave. The pressure wave can be detected as ultrasound at the tissue surface. "It goes in as light but comes out as sound," Gambhir said, and three-dimensional images can be reconstructed from the absorbent structures.He also described a diagnostic technique of injecting gas-filled bubbles to wander throughout the body looking for cancer cells. Once these cells have been "interrogated" and destroyed, ultrasound is used to "burst" (or did he say "burp"?) the bubbles.Gambhir acknowledged that the technologies are slightly ahead of biology, but the development of an aggressive biomarker is on the horizon. "As technologies to solve the problem of early cancer detection are realized, they will also lead to benefits for cancer management."Amazing!