Siri Lynn, a marketing consultant from Fairfield, Conn., had a friend diagnosed with breast cancer two years ago. Recently, Lynn said, she developed breast cancer herself and was referred to Yale-New Haven Hospital by her friend. Now, she is the first Connecticut patient enrolled in a clinical trial for a novel breast cancer treatment at the hospital.

Dr. Joanne Weidhaas is co-coordinating the Yale effort as part of an international study on an emerging treatment called accelerated partial breast irradiation. The little-known procedure, which has been around for more than 10 years, will be compared in effectiveness to traditional whole breast irradiation by the ongoing study.

“[The research is] a change in paradigm. The question is, do we need to treat the entire breast?” Weidhaas said.

Whether this alternative treatment will work as well as traditional methods is an area of controversy, she said.

Although both methods are relatively safe, PBI treatment lasts only five days, while whole breast irradiation takes as long as six weeks. The twice daily PBI sessions take just minutes and minimize radiation exposures to healthy tissue. The study, funded by the National Cancer Institute, is being conducted at 150 sites and involves 3,000 women.

Weidhaas, a professor of therapeutic radiology at the Yale School of Medicine, is responsible for reviewing the protocol, selecting patients, and collecting data.

Now in phase-three clinical trials, one step away from FDA approval, Weidhaas said the treatment seeks to strike a balance between killing a tumor and hurting the surrounding tissue.

She said 40 percent of women with breast cancer choose to have radical mastectomies rather than take time off for the lengthy standard radiation treatment. Additionally, 25 percent of women who had a lumpectomy skip the subsequent radiation, Weidhaas said, which is critical to eradicating any cancerous traces.

By cutting treatment time down to one week, PBI gives women more options, she said; however, the treatment is not for everybody.

“There’s still a place for whole breast irradiation,” said Dr. Bruce Haffty, professor of radiology at the Medical School and breast cancer program director. “But now is the time to put it to the final test.”

Haffty said the Medical School has several other breast cancer clinical trials on the table and is continually finding ways to improve radiation and examine cancer dynamics at the molecular level.

“As long as you have a general idea, then there are opportunities for advancement,” said Renard Walker, a breast cancer researcher at the National Cancer Institute.

Walker said the Yale team has had much success but much more needs to be done.

Patricia Spicer, breast cancer program coordinator at the nonprofit support organization Cancer Care, said that even with initial success, it will take a while for the general public to accept PBI. Currently only a few patients even know about this alternative treatment, so the underlying demand is not great, she said.

Yet for those who do have access to such clinical studies, the rewards can be great. Lynn said she was very lucky to hear about the study and has complete faith in the Yale investigators.

“From the parking attendant to doctors, it has been an awesome experience,” she said.