Dr. Sanjiv Gambhir
develops tool to image tumours
Dr. Sanjiv Gambhir and his imaging system
A team led by Dr. Sanjiv Gambhir has developed a new type of imaging system capable of picturing tumours to a precision of a trillionth of a meter. The new system, which uses Raman spectroscopy, will be of great use to doctors who are currently hampered by the limited extent to which they can see such tumours.
Using a microscope modified to detect Raman nanoparticles, Gambhir's team was able to see targets a thousand times smaller than what is currently obtainable. Signals from Raman spectroscopy are stronger and longer-lived than other available methods, and the type of particles used in this method can simultaneously transmit information about several molecular targets. "We can measure one or two things at a time, but with this, we can now likely see 10, 20, 30 things at once," said Gambhir, director of the Molecular Imaging Programme at Stanford University Medical Centre and also head of nuclear medicine.
Gambhir compared Raman spectroscopy work to the development of positron emission tomography (PET) over two decades ago. PET is now a routine imaging technique that uses radioactive molecules to generate a three-dimensional image. "Nobody understood the impact of PET then," Gambhir said, referring to its discovery. "Ten or 15 years from now, people should appreciate the impact of this."
Raman spectroscopy is named after physicist C.V. Raman, whose 1928 discovery of a radiation effect that bears his name (Raman effect) won him the 1930 Nobel Prize in physics. Raman effect is created when light is shone on an object. Roughly one in 10 million photons bouncing off the object's molecules gains or loses energy, called Raman scattering. This scattering pattern, called a spectral fingerprint, is unique to each type of molecule and can be measured.
Sanjiv Sam Gambhir is a Professor of Radiology and Bioengineering at Stanford University. He is the Head of Nuclear Medicine and Director of the Molecular Imaging Program at Stanford (MIPS). He trained at the University of California Los Angeles (UCLA) Medical Scientist Training Program, where he obtained both his M.D. and Ph.D. He completed his Medicine and Nuclear Medicine training at UCLA and was a Professor of Molecular Pharmacology, Vice-chair of Molecular & Medical Pharmacology and Director of the Crump Institute for Molecular Imaging before moving to Stanford University in 2003.
Dr. Gambhir has a translational laboratory that focuses on molecular imaging including new probe development for positron emission tomography (PET) and multimodality molecular imaging including the use of optical imaging. His laboratory has developed methods to image gene/cell therapy in living subjects including humans. He has developed many strategies for imaging basic cell/molecular events including signal transduction, gene expression, and cell trafficking. Dr. Gambhir also has extensive experience with clinical FDG PET and has developed many of the management algorithms for cancer patients including cost-effectiveness models.
Gambhir, who is known to move easily and quickly across physical, biological and medical discipline boundaries, has an impressive list of accomplishments. Much of his lab's research involves looking at which molecules could be targeted to image a number of processes, with a particular focus on cancer and cardiovascular disease.
As a researcher, he uses technologies such as micro positron emission tomography, bioluminescence optical imaging with a charge coupled-device camera, fluorescence optical imaging and micro computerized axial tomography for investigation with small animal models. He and his laboratory researchers have developed methods to image gene/cell therapy in living subjects, and he has developed several small animal–imaging strategies for studying basic cell/molecular biological events including signal transduction, gene expression and cell trafficking.
Dr. Gambhir currently oversees the activities of over 20 graduate students and postdoctoral fellows in his own lab and over 100 scientists/staff in the Molecular Imaging Program at Stanford. He is funded by the National Institutes of Health and several Foundations.
In May, 2006 SNM named Sanjiv Sam Gambhir as Recipient of 2006 Paul C. Aebersold Award for Outstanding Achievement in Basic Nuclear Medicine Science. The honor was given to the wellknown Stanford University scientist for contributing extensively to Molecular Imaging, Basic Science of Using Radioactive Tracers
He recently received the 2006 Hounsfield Medal, 2004 gold medal award by the Society of Molecular Imaging, the 2004 distinguished scientist award by the Academy of Molecular Imaging, and the 2003 Holst Medal for his contributions to the field of molecular imaging. He is President of the Academy of Molecular Imaging (AMI) and associate editor of several journals.
