The study led by Dr. Kevin Albuquerque, radiation oncologist at the Cardinal Bernardin Cancer Centre, Loyola University Health System, Maywood, Illinois, U.S.A, states that PBRT is a viable option for women for women.
"One of the first questions a woman newly diagnosed with breast cancer asks is 'what impact will radiation have on my body?' This study helps allay some fears," Albuquerque said.
Traditionally, for early-stage, small-tumour, node-negative breast cancer whole-breast radiation therapy has been the standard of care.
"PBRT is a viable option for women who are eligible," Albuquerque said.
In the study, 30 women, over 45 years of age, who had a lumpectomy for early stage, small-tumour, node-negative breast cancer were divided into two treatment groups: the Whole-Breast Radiation Therapy group and the partial-breast radiation therapy group.
During the study, the researchers conducted psychological tests to all the participants five times: first, before any initiation of radiation therapy; second, at three weeks after completion of radiation therapy; and then at six-, nine- and 15-weeks post therapy.
The group of tests included one measuring tension, depression, anger, vigour and fatigue.
Another measured well being at the emotional, physical, functional and social levels.
One test addressed aspects specific to breast cancer: appearance, illness, treatment side effects and sexuality.
For administering the tests each time, blood samples were collected to assess natural killer cell activity and number of circulating lymphocyte subsets, indicators of immune system function.
While limiting risk to adjacent healthy tissue the target of Whole Breast-Radiation Therapy was the entire breast with large-field radiation.
In Partial-Breast Radiation Therapy a catheter is left in the woman for five days.
When the patient comes in for a PBRT treatment, the catheter is then attached to a machine that delivers a radiation "seed" for therapy.
Each time therapy is finished, the seed is taken out and the patient goes home.
"No radiation seed remains in the breast overnight," Albuquerque said.
In the analysis, the researchers found that at six weeks, women who received Partial-Breast Radiation Therapy showed increased energy, compared to women who received WBRT.
"They perceive their life is not so drastically changed," he said.
"At 9 and 15 weeks, the PBRT women perceived less stress than the WBRT women," Albuquerque said.
"When analysing six-week data for change from baseline, women who had been treated with PBRT had improved energy and quality of life compared to those who had received WBRT," he added.