University of Minnesota
School of Physics & Astronomy


Physics Research Could Make Cancer Treatment More Effective

Pamela Sooriyan
Pamela Sooriyan
Richard Anderson

Pamela Sooriyan is a graduate student in biological Physics working with John Broadhurst. Her research involves bringing phenomenon in nuclear physics to cancer treatment. She is applying giant dipole resonance, a well-known nuclear phenomenon that occurs at energies that are typically at the higher end of the photon beam spectrum generated in clinical linear accelerators, to possibly increase the radiation dose given to tumors in bone.

Sooriyan says that patients who have a tumor that is deeply imbedded in bone can only take as much radiation dose to bone as the surrounding normal tissue and skin will tolerate. Sooriyan’s experiments use a higher energy photon beam in order to induce a resonance process in which the photons of the desired energy range preferentially interact with calcium in the bone, giving more dose to bone than the surrounding tissue. This would allow doctors to increase the tumor dose without having to increase the given dose to surrounding tissue beyond acceptable values. Her experiments offer the benefits of utilizing higher atomic number elements in the tumor in order to increase the tumor dose, without having to introduce a foreign substance in to the body.

One of the challenges of this research is that in order to get the desired results, this resonance has to be maximized relative to the other non-resonant interactions that take place in the treatment area. Her task is to come up with a procedure that minimizes those ineffective but unavoidable reactions.

She is currently experimenting on pieces of meat and bone and says that the next phase will be animal testing. So far the results have shown what they are hoping for: a higher dose delivered to the bone with less impact on the surrounding tissue. She is working on a paper she hopes to publish soon.

She is also working on modifying the already available higher energy beams in clinical accelerators in order to make this treatment practical and cost-effective. This part of her research involves modeling and running simulations with the goal of being able to use the higher energy beams which currently offer no significant clinical advantage over lower energy photon beams.