LSU Medical Physicist Works to Improve Treatment Outcomes for Postmasectomy Patients


September 8, 2016

BATON ROUGE - About one in eight U.S. women will develop invasive breast cancer over the course of her lifetime. An estimated 231,840 new cases of invasive breast cancer are expected to be diagnosed in women in the U.S. and about 40,290 women are expected to die from breast cancer this year. Dr. DiTusa and Dr. ZhangLSU Assistant Professor of Physics Rui Zhang was awarded a grant from the National Cancer Institute to improve treatment outcomes for breast cancer patients.

A mastectomy is highly recommended for patients with locally advanced primary breast cancer and extensive lymph node involvement. Due to the prevalence of microscopic diseases after the mastectomy, postmastectomy radiotherapy, or PMRT, is commonly performed on these patients to sterilize the residual tumor cells, and has been shown to improve the overall survival rate among patients with invasive breast cancer by reducing the risk of tumor recurrence and cancer mortality. However, long term survivors may develop life threatening acute and chronic treatment-related toxicities after radiotherapy. For example, the risk of ischemic heart disease increases with breast cancer radiotherapy dosages, according to previous studies.

PMRT options include external beam photon therapy, electron therapy and proton therapy, each with various degrees of sophistication. Most of these technologies will provide comparable target coverage, while the dose to surrounding normal tissues varies greatly. The more advanced techniques, like intensity modulated radiotherapy and proton therapy, have the potential to improve long term survival by constraining doses to radiosensitive organs, but evidence from an outcome study will not be available until years or decades later. Furthermore, the literature is largely incomplete regarding systematic comparison of potential benefits of advanced technologies for PMRT. Clinical and policy decision making is difficult because of the many possible treatment strategies, the rapid technological advancement of radiotherapy and an insufficient evidence base. 

Zhang’s research evaluates the efficacy of various PMRT techniques and offers rigorous theoretical evidence that will help guide clinical decision making, especially modality selection for PMRT. The National Cancer Institute awarded him a $600,000 grant to support this work.

“With this grant, we will improve understanding of the benefits, weaknesses and effectiveness of various radiotherapy modalities, especially advanced-technology modalities, in the treatment of postmastectomy breast cancer patients.  It will facilitate offering evidence-based, effective patient care and can potentially benefit millions of breast cancer patients in the United States,” Zhang said.




Mimi LaValle

LSU Physics & Astronomy

External Relations Manager