An eight-year study, performed at
Hoag Memorial Hospital Presbyterian, Newport Beach, CA and supported by philanthropy has potential implications
for how thousands of women are treated for breast cancer. The study findings,
which were published on-line and in the October 2018 issue of the
Annals of Surgical Oncology (Ann Surg Oncol {2018} 25:2987-2993}, a leading peer-reviewed journal,
found that
intraoperative radiation therapy (IORT) is a clinically effective, faster and easier alternative to whole breast
radiation therapy following breast-conserving surgery for selected low-risk patients.
IORT uses a miniaturized X-ray source to deliver a full course of targeted
radiation directly within the tumor cavity where the cancer is most likely
to recur, destroying cancer cells and reducing the risk of injury to nearby
healthy tissues. IORT helps reduce potential side effects that are more
common with whole breast irradiation and significantly reduces the amount
of time required for treatment and recovery.
Hoag Memorial Hospital Presbyterian utilizes iCAD’s Xoft® Axxent® Electronic Brachytherapy (eBx®) System® to administer IORT treatments.
In traditional breast cancer treatment, radiation is delivered externally
and to the entire breast. This process can take anywhere from 16 to 35
visits over a period of three to six weeks. IORT is delivered as a single
dose of radiation therapy, during the surgical lumpectomy, eliminating
weeks of travel and disruption to daily life. The total treatment time
is an average of 11 minutes and is a quarter of the cost of traditional
treatment. The early results demonstrate a recurrence rate following IORT
in this study of 3.9 percent at four years, which is slightly higher than
traditional whole breast radiation therapy, but far quicker and more cost-effective.
Furthermore, using IORT initially does not eliminate the potential use
of excision and whole breast radiation should there be a local recurrence
in the future. These results while promising are still deemed to be early
and therefore patients must be screened carefully by both surgeons and
radiation oncologists to be considered eligible.
“On average, IORT can reduce 30 days of treatment to less than 30
minutes. The benefits are obvious,” said
Dr. Melvin Silverstein, M.D., Medical Director of the Hoag Breast Center, Gross Family Foundation Endowed
Chair in Oncoplastic Breast Surgery at Hoag, and Clinical Professor of
Surgery at the Keck School of Medicine, Los Angeles, California. “Eliminating
three to six weeks of radiation therapy reduces emotional stress and allows
patients to quickly return to their normal life. Hoag’s highly experienced
IORT team has treated more than 1,100 patients with IORT, the most cases
to date for a single site in the United States. The results of this study
have important implications for women around the country just diagnosed
with breast cancer and currently considering their treatment options.”
The current paper reported the first 1,000 early-stage breast cancers (984
women) enrolled in a prospective X-ray IORT trial from June 2010 to August
2017. Patients included individuals 40 years of age and older, with lymph
node negative cancer and with favorable pathology. All tumors were treated
with breast-conserving surgery and IORT administered using the Xoft System.
With a median follow-up of 36 months, there have been 28 ipsilateral local
recurrences, ten of which were DCIS and 18 invasive. There have been four
regional nodal recurrences and one distant recurrence. Fourteen non-breast
cancer deaths have been reported, but there are no breast cancer deaths.
The low complication rates reported by Hoag, as well as the low recurrence
rates reported in this study, support the continued study of IORT in selected
women with low-risk breast cancer.
About one-third of all patients with breast cancer could be candidates
for IORT. According to the National Breast Cancer Foundation, it is estimated
that more than 250,000 women will be diagnosed each year with breast cancer,
which means about 84,000 women could be candidates for this procedure.
IORT with the Xoft System is currently being administered at more than
50 sites worldwide and has been used to successfully treat more than 3,000 patients.