Kimberly S. Corbin, MD
There are clear advantages to using proton beam radiation instead of standard radiation in certain patients with breast cancer, said Kimberly S. Corbin, MD; however, there is still work to be done before this practice becomes more widespread.
State of the Science Summit™ on Breast Cancer, Corbin shed light on the use of proton radiation therapy in the space and which patients may benefit from this approach.
OncLive: How does proton therapy differ from standard radiation?
: Proton therapy is [comprised of] particles, [while] standard radiation is [comprised of] photons. By way of the physical properties of beam particles, they are heavier, and they have different dosimetric characteristics; [this enables us to] better spare tissue for radiation therapy. Usually when X-rays interact with tissue, they deposit energy along their path, and there is an entrance dose and an exit dose.
But for proton therapy, one of its dosimetric characteristics is that there is very little exit dose from radiation. Therefore, we can do a nice job of shaping the dose, while maximizing the ability to spare nontarget tissue from radiation.
What patients benefit the most from this therapy?
I primarily take care of patients with breast cancer, so that is the context with which I will answer the question, although this can be applied to many different kinds of malignancies. In terms of patients with breast cancer, a lot of patients have the need for comprehensive target volume coverage. Generally, this is for patients with the need for deep nodal detection or patients with a unique anatomy that makes standard radiation particularly high-risk. At the other end of the spectrum, proton therapy has a role for patients with early-stage breast cancer who are interested in a type of treatment called accelerated partial breast irradiation. That type of treatment is very focused and is used to target small volumes of tissue.
... to read the full story