It seems that one out of every few fictional villains ends up resorting to the same method for destroying the earth: hitting it with a giant laser. Although these fictional plans never elaborate on the real world physics, in some ways the villains have the right idea. Lasers are powerful tools and simply used as a heating device, they can kill cells. Thermal therapy is being used to kill cancer cells in tumors that other methods fail to eliminate, but as with radiation therapy there is a risk of overheating healthy cells, or not heating the tumor cells enough.  

A new idea for improving thermal therapy was recently published in PNAS and presented at the AAPM session “Frontiers in Medical Physics,” by the young research assistant Xuangfang (Leo) Ding from Wake Forest University. Using multi-walled carbon nanotubes (MWCN’s – shown above) Ding and his collaborators hope to make guided laser cancer removal safer and more effective.

The treatment injects cancer tumors with MWCN’s,  and uses a guided near infrared laser to heat them up and deliver a fatal temperature rise to the cancer cells.  The laser pulse is low energy (3 W/cm²) and fast (30 seconds per dose). The team uses Magnetic Resonance Temperature Imaging, MRTI, to identify the tumor and then to monitor the tumor’s temperature as well as the temperature of the surrounding tissue. Trials with mice showed a significant rise in the temperature of the cancer cells injected with the MWCN’s, compared to without. And, the tumors were far less likely to come back.

The treatment can be used non-invasively on superficial tumors like skin cancer, and with minimal invasivity to deeper tumors by inserting a small laser optic fiber into the target as well as the MWCN’s. The exception is lung cancer, where the motion of the tumor would cause too great an error in the MRTI.

Since carbon nanotubes are not approved by the FDA, it’s uncertain when the team can begin clinical trials, and they are still investigating any potential side effects of the MWCN’s.