Nanoparticle imaging technique 'could improve brain surgery'

In collaboration with the Press Association

A new 'nanoparticle'-based imaging technique could improve the accuracy of brain tumour surgery, according to lab work by US scientists.

The Stanford University scientists were able to precisely remove glioblastomas in mice by using the tiny particles to home in on and highlight the brain tumours.

The imaging technique uses three types of brain scan before and during surgery. This three-pronged approach greatly improves the image quality of the outer edges of the brain tumour. This means surgeons can remove more of the tumour than previously possible.

Glioblastomas are particularly rough-edged tumours, so even the most skilled surgeons cannot remove the entire tumour while leaving the healthy parts of the brain intact.

If developed further, the new technique could improve the precision of brain tumour surgery, and ultimately improve patient survival.

The nanoparticles used in the study are essentially tiny gold balls coated with factors that help imaging.

The three methods of scanning involved coating the nanoparticles with a magnetic resonance imaging contrast agent called gadolinium; 'photoacoustic imaging', where pulses of light are absorbed by the nanoparticle's gold cores, making them easier to see; and 'Raman imaging'.

This final imaging technique picked up extremely low levels of light given off by the gold particles. It was particularly accurate at flagging up residual cancer cells left after the bulk of the tumour was removed.

Lead author, Professor Sam Gambhir said: "Now we can learn the tumour's extent before we go into the operating room, be guided with molecular precision during the excision procedure itself and then immediately afterwards be able to 'see' once-invisible residual tumour material and take that out too."

Cancer Research UK scientist, Dr Nicola Sibson, from the Gray Institute, said the research was at an early stage but a “very exciting step” towards improved brain imaging.

“This type of ‘multimodal’ approach to tumour imaging has great potential and means these techniques could help to make brain surgery more precise.

“While conventional imaging techniques are reasonably good at defining the location of brain tumours, any improvements in defining their outer edges could ultimately lead to improved survival. The next step will be to see if this lab work translates into the real-world setting of the clinic.”

Copyright Press Association 2012

References

  • Kircher, M. et al. (2012). A brain tumor molecular imaging strategy using a new triple-modality MRI-photoacoustic-Raman nanoparticle Nature Medicine DOI: 10.1038/nm.2721