for those deciding between balloon catheter APBI and 7 week whole breast radiation

[Lani]

criteria for who may be a candidate spelled out:
Ultrasound Helpful Prior to Breast-Sparing Brachytherapy

Richard Hyer
November 30, 2006 (Chicago) — The results of a 4-year study from Northwestern University support the role of ultrasound guidance for percutaneous placement of balloon catheters prior to breast-sparing brachytherapy. The study was announced in a news conference here at the 92nd scientific assembly and annual meeting of the Radiological Society of North America (RSNA).

"The purpose of our study is to describe and report our experience in adapting ultrasound-guided breast interventional techniques, that most breast radiologists are expert at, for percutaneous placement, in breast imaging suites, of this new therapeutic device for brachytherapy following lumpectomy in early stage breast cancer," said Ellen B. Mendelson, MD, at a news conference.

Dr. Mendelson is director of breast imaging for Northwestern University Feinberg School of Medicine's Department of Radiology at the Lynn Sage Breast Center in Chicago, Illinois.

The device used in the study is a balloon catheter device known as MammoSite (Cytyc Corp, Marlborough, Massachusetts). Dr. Mendelson said that Northwestern began doing these procedures in 2002 at the request of the hospital's radiation oncologists.

More than 212,000 new breast cancers will be diagnosed this year in the United States. Screening mammography has made possible the detection of tumors at smaller sizes and lower stages and, according to Dr. Mendelson, most eligible women select breast conservation over radical mastectomy.

"Survival has been found, in several decades of follow-up, to be equal in radical mastectomy and lumpectomy with radiation therapy, stage for stage, in breast cancer patients," Dr. Mendelson told the conference.

Whole-breast irradiation is the traditional standard of care, and for most women, this means a 6-week commitment with treatment 5 days a week. Partial breast irradiation (PBI) involves less time. This alternative can take several forms, including the insertion of radioactive iridium seeds, 3-dimensional conformal external beam radiotherapy, and intraoperative radiation therapy (IORT).

[Lani]

According to Dr. Mendelson, early data (<5 years) has shown similar recurrence rates (<2% to approximately 6%) in whole breast irradiation and lumpectomy.

Catheter-directed PBI was approved by the FDA in 2002. One clear advantage is a treatment time of 5 to 7 days.

Dr. Mendelson described Northwestern's retrospective study of all cases of catheter-directed PBI between May 2002 and April 2006. Investigators reviewed medical records, ultrasounds, mammograms, pathology, and specimen imaging.

During the 4-year period, 75 patients with breast cancer underwent ultrasound for eligibility after lumpectomy, and 44 (59%) met ultrasound eligibility criteria for PBI, with 31 (41%) ruled ineligible. In more than 90% of those who were ineligible, the skin-to-seroma distance was the disqualifying factor, usually related to depth of surgical closure. Nine of the 44 eligible women did not choose PBI. Of the 35 patients in whom balloon catheters were placed, 34 (97%) completed PBI (the sole ineligible patient had been found to have inadequate tissue thickness).

Dr. Mendelson concluded that this study found the procedure safe, sufficient, relatively economical, and minimally invasive, but she noted that the procedure requires careful scanning for eligibility. When compared with surgical placement at the time of lumpectomy, she said that this procedure allows time for a pathologic analysis to be completed to confirm that the margins are disease-free, and it allows the patient time to explore other therapeutic alternatives, including PBI or whole-breast irradiation.

In the Northwestern protocol, the tumor size has to be less than 3 cm (ductal carcinoma in situ) for stage 0 tumors, 2 cm or smaller for stage 1 tumors, and 5 cm or smaller for stage 2. Margins and lymph nodes should be negative.

"The key to eligibility is careful, real-time scanning, in perpendicular planes, to find the minimum thickness between the skin and the top of the fluid collection. That should be at least 6 mm," said Dr. Mendelson. The cavity size should be at least 3 cm.

Dr. Mendelson uses prophylactic antibiotics and local anesthetic (2% lidocaine). A trocar is used to create a tract from the skin to the seroma. The shape of the balloon to be inserted is matched to the shape of the wound.

[Lani]

The balloon is injected with contrast material and saline, and then the patient is sent to radiation oncology for dosing, ie, the introduction of radioactive seeds into the saline-filled balloon. Dosimetry is done with computed tomography (CT).

"The patient may feel some pressure, but there is really no pain associated with the procedure at all," Dr. Mendelson told the conference. The entire procedure is guided by ultrasound.

Patients are followed up with mammography and ultrasound. According to Dr. Mendelson, whole-breast irradiation often reveals significant edema, and this is lessened significantly with the balloon catheter procedure.

Responding to a question at the news conference, Dr. Mendelson noted that there is currently a National Surgical Adjuvant Breast and Bowel Project trial involving 3000 subjects in 2 treatment groups, 1 group receiving whole-breast irradiation, the other PBI. However, in the PBI group of this trial, there is a choice in external-beam radiation using the Mamocyte device or multiple catheters. She did not have the number of patients who chose the former.

In the Northwestern study, there was cancer recurred in 1 patient. "This surgery was not done at Northwestern," said Dr. Mendelson.

"No surprises here, but very good clinical application," said Nancy Ellerbroek, MD, from Valley Radiotherapy Associates of Valencia, California. Dr. Ellerbroek was not affiliated with this study and was a spokesperson provided by RSNA. "I think all patients having a choice would prefer having an ultrasound screening, such as this, to a CT scan with the balloon already in place."

According to Dr. Ellerbroek, ultrasound is in wider use.

"Many surgeons now use ultrasound in the operating room to screen for the distance between the seroma and the skin, while there's still a possibility of intervention to reapproximate tissue, and render the patient eligible for placement of a balloon catheter at a later date. It would be best for patients if more surgeons and radiation oncologists used ultrasound on a routine basis, and this study gives good data to support that."

This study did not receive commercial support. Dr. Mendelson is on the advisory board of the Medipattern Corporation.

RSNA 92nd Scientific Assembly and Annual Meeting: Abstract SSM01-05. Presented November 29, 2006.

[Hopeful]

pretty thoroughly, as I wanted to recieve the least amount of radiation that I could to anything but the tumor bed. I was disqualified because of the skin-to-seroma issue. I was told this really works best in large breasted women, which I definitely am not. The only caveat is a study I saw that said women who had the ballon inserted at the time of lumpectomy had a lot of problems with persistent hematoma/seroma up to a year afterwards. Also, the surgeon needs to know if you are going to have this form of raditation therapy at the time the surgeury is done because they can't leave in clips that can puncture the balloon. Hope these comments are helpful to anyone considering the treatment.

Hopeful

[Bev]

I too was too small breasted after lumpy for this. It will be interesting to see how things eventually pan out. BB