Among almost 30,000 Medicare beneficiaries treated for early-stage breast cancer, the complication rate was 17% higher with breast brachytherapy than with whole-breast irradiation (WBI), according to a study published online October 22 in the Journal of Clinical Oncology.
This casts some doubt on the widespread use of breast brachytherapy.
Although WBI has been the standard of care for 20 years, "currently there are no large randomized controlled trials or population-based studies confirming brachytherapy as a safe and effective alternative to WBI," study author Carolyn Presley, MD, from Yale University School of Medicine in New Haven, Connecticut, and colleagues write.
"Given the higher costs associated with brachytherapy, the higher risk of complications suggests that clinicians, patients, and policy makers should scrutinize the use of this treatment modality," they note.
This suggestion has drawn criticism from a European expert who says the brachytherapy technique used successfully in Europe provides better results than the techniques used in the United States.
"My opinion is that this debate in the United States is about [single-channel intracavitary balloon] brachytherapy, not interstitial multicatheter brachytherapy," Csaba Polgár, MD, PhD, director of the Centre for Radiotherapy at the Hungarian National Institute of Oncology in Budapest, told Medscape Medical News in an email. This study says nothing about good old CT image-guided interstitial brachytherapy, which is what is used in Europe.
Dr. Polgár presented the results of a randomized phase 3 trial at the European Society for Radiotherapy & Oncology (ESTRO) annual meeting earlier this year, as reported at the time by Medscape Medical News. They showed that interstitial brachytherapy and WBI have equivalent disease control and complications, but that treatment with interstitial brachytherapy is shorter and cosmetic outcomes are better.
In their study, Dr. Presley and colleagues weren't able to distinguish between the type of brachytherapy (i.e., number of catheters) for all their patients. "For the subgroup undergoing brachytherapy in 2009, it looks like roughly half had single catheter and about one third had multiple catheter; for the remainder, this was unclear from the claims data," principal author Cary Gross, MD, who is also from the Yale University School of Medicine, told Medscape Medical News in an email.
From the national Centers for Medicare and Medicaid Services Chronic Condition Data Warehouse, which contains all fee-for-service Medicare claims, the researchers identified 29,648 women (66 to 94 years of age) who received adjuvant radiation therapy in 2008 or 2009 after breast-conserving surgery (BCS) for invasive breast cancer.
Of these women, 4671 (15.8%) received brachytherapy; the remainder received traditional external-beam or intensity-modulated WBI.
Medicare claims were used to identify complications in the year after BCS (the primary outcome), including wound complications, fat necrosis, infection, blood vessel injury, pericarditis, lung injury, nerve damage, and rib fracture.
For 18,990 patients, there was a full year of post-BCS claims. After adjustment for patient characteristics and treatment-selection bias, the researchers estimated the complication rate to be 16.8% higher with brachytherapy than with WBI (35.2% vs 18.4%; P < .001).
Wound and skin complications accounted for most of this difference (33.7% vs 16.8%; P < .001); there was no significant difference in deep tissue and bone complications (4.4% vs 2.5%).
Brachytherapy has been promoted over WBI because it diminishes radiation exposure to the heart, lungs, and skin. However, it also involves "relatively high surface radiation doses to and around the lumpectomy cavity," which increases the risk for skin and wound complications, Dr. Presley and colleagues note.
This is not the case for the CT-guided multicatheter brachytherapy used in Europe. "It seems that interstitial brachytherapy yields significantly less 1-year skin toxicity than WBI," Dr. Polgár said. These results come from the GEC-ESTRO phase 3 trial, which he expects to present next spring.
Uptake of Procedure in the United States
The use of brachytherapy is increasing in the United States, perhaps not always for the right reasons, note Dr. Presley and her colleagues. The overall rate of brachytherapy in their sample was 15.8%, which is substantially higher than the 10.0% rate reported in 2006 and the 1.0% rate reported in 2000; however, there was wide variation across hospital referral regions (HRRs).
The "use of brachytherapy tended to be higher in the southwestern portions of the country and along the east coast, with lower levels in the middle, north, and western regions of the country," the write. Of the HRRs with at least 20 patients, there were 20 in which no patients received brachytherapy. The HRRs with the highest use of brachytherapy were Ogden, Utah (65.4%) and Lafayette, Indiana (71.4%), the researchers report.
This "marked regional variation in utilization suggests that nonclinical factors play an important role in its dissemination," they note.
"This should give us pause," writes Jennifer Malin, MD, medical director for oncology at WellPoint and associate professor of medicine at the David Geffen School of Medicine at the University of California, Los Angeles, in anaccompanying editorial.
"After a capital investment has been made to acquire the device, as the recent studies by Presley et al and others have shown, uptake of the new technology occurs even in the absence of evidence of improved or even comparable outcome," she explains.
Pointing to "the peril of adopting a new therapy on the basis of hope instead of science," she cited the need for randomized controlled trials "before the dissemination of new technology."
At the ESTRO meeting in May, Dr. Polgár and another European expert suggested that the widespread adoption of many of the single-entry catheters used in the United States (MammoSite, MammoSite multilumen, Contura, Savi) is less about hope and more about money.
"As always in the United States, the main issue is with reimbursement," said Dr. Polgár. "A few years ago, we projected [the American] result. We warned them," he said. "We used [MammoSite] in a small trial [Radiother Oncol. 2006;79:316-320], and we now have a 64% telangiectasias rate in that population."
"It's really a disaster because it was [reimbursed], so a lot of people jumped on this technique without any real assessment of its value, and it became very popular very quickly," explained Christine Haie-Meder, MD, a radiation oncologist at the Institut Gustave Roussy in Villejuif, France, at the ESTRO meeting. "With MammoSite, there is one source of irradiation, so you cannot have a good dose distribution. The Europeans did not like this concept," she said.
"Since its introduction in May 2002, the MammoSite has been under constant assault from multiple groups," Frank Vicini, MD, from William Beaumont Hospital in Royal Oak, Michigan, told Medscape Medical News. He was principal investigator for the MammoSite Breast Brachytherapy Registry Trial (Cancer. 2005;15;104:1138-1148).
"Initially, many argued it was widely adopted because of financial advantages," said Dr. Vicini. "The monetary advantages have vanished, but much of the animosity toward a commercially sponsored new device have persisted," he told Medscape Medical News.
Although "there may be subtle differences" between brachytherapy techniques used in Europe and the United States, "in our phase 3 trial, where both types are used (NSABP B39/RTOG 0413), we have not seen any differences in the rates of toxicity between any form of brachytherapy versus whole-breast irradiation, he and his colleagues explain (Int J Radiat Oncol Biol Phys. 2010;77:317).
Echoing Dr. Malin's call for randomized controlled trials of these treatments, Dr. Vicini said studies such as the one by Dr. Presley and colleagues are prone to methodological pitfalls "that can render their results unreliable."
"My concern is that these types of observational analyses create needless panic among the thousands of women treated with the technique, which I believe is irresponsible of the authors and literally stops the enrollment of patients in clinical trials designed to test the technique," Dr. Vicini told Medscape Medical News.
"What you may not realize is that whole-breast irradiation represents a substantial revenue source for most centers (including academic). If brachytherapy is shown to be equivalent to WBI, this revenue will drop dramatically. This is what you are not hearing from these academic centers," he explained.
The study was supported by a grant from the National Cancer Institute. Dr. Polgár and Dr. Vicini have disclosed no relevant financial relationships. Dr. Gross reports serving in a consultant or advisory role for Fair Health. Dr. Gross and coauthor Beth-Ann Lesnikoski, MD, from the University of Miami Miller School of Medicine in Florida, report receiving grants from Cianna Medical and Medtronic for work on the sharing of clinical trial data. Dr. Malin reports owning stock in WellPoint.
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