Breast Brachytherapy in the News, Part 3: Who is eligible for brachytherapy treatment?

Today's blog continues our series on the latest news on brachytherapy for breast cancer with a focus on how patients are selected for brachytherapy. We'll highlight a Journal of the National Cancer Institute study which compared patient selection in practice to the recommendations of the 2009 American Society for Radiation Oncology consensus guidelines, known as ASTRO-G.

Links to the study, guidelines and media reports may be found on the brachytherapy page of our LATESTBreastCancer.com website.

Background

Part 1 of this series provided a brief overview of accelerated partial breast irradiation (APBI) and brachytherapy, including descriptions of the Mammosite, Contura Multi-Lumen Balloon and SAVI Applicator brachytherapy systems.

Part 2 discussed a presentation at the 2011 San Antonio Breast Cancer Symposium on mastectomy rates and side effects associated with brachytherapy.

Today's blog addresses the question of patient eligibility for brachytherapy treatment.

The ASTRO-G consensus guidelines for patient selection

In 2009, the American Society for Radiation Oncology published a consensus statement with guidelines for brachytherapy use. (The link to the statement is dated November 10, 2011 on our website.)

Based upon clinical trial data at the time, the consensus statement defined three patient types - "suitable," "cautionary" and "unsuitable" for brachytherapy treatment.

Patients suitable for brachytherapy would be at least 60 years old, with no BRCA 1/2 mutations, tumors no larger than 2 cm, estrogen-receptor positive, node-negative invasive ductal carcinoma with no DCIS.

Factors which would result in a cautionary status would be patient age between 50 and 59 years old, tumor size between 2.1 and 3 cm, estrogen-receptor negative status, invasive lobular carcinoma, or DCIS less than 3 cm.

Factors which would result in an unsuitable status would be patient age less than 50, BRCA 1/2 mutations, tumor size greater than 3 cm, DCIS greater than 3 cm, node-positive status and use of chemotherapy before surgery (neoadjuvant chemotherapy.)

The Journal of the National Cancer Institute study

A December 16 Journal of the National Cancer Institute study compared the use of brachytherapy in patients from 2000 to 2007 to the recommendations of the 2009 ASTRO-G guidelines. US News and World Report/HealthDay and the Oncology Nurse Advisor covered the study.

The researchers reviewed data of over 138,000 women. In sum, 2.6% were treated with brachytherapy. Brachytherapy use increased from 0.4% in 2000 to 6.6% in 2007.

Of the women treated with brachytherapy, 32% would be classified as suitable under the ASTRO-G guidelines. 29.6% would be considered cautionary and 36.2% would be considered unsuitable.

Considering the entire population of 138,000, 5% of those suitable for brachytherapy were treated with it. 3.4% of patients considered cautionary and 1.6 of those considered unsuitable were treated with brachytherapy. Looking at it another way, 98.4% of patients considered unsuitable were not treated with brachytherapy. Even 95% of those considered suitable did not receive brachytherapy.

Interestingly, the Oncology Nurse Advisor noted that the steepest increase in brachytherapy use was among suitable patients, ranging from 0.7% in 2000 to 11% in 2007.

It should be noted that the ASTRO-G guidelines were not available until two years after the women in the study were treated. It will be interesting to see future studies on patient selection after the guidelines were published.

For more news and research on brachytherapy, please visit the treatment pages of the LATESTBreastCancer.com website. From the home page, click the Treatments tab and search for "brachytherapy" in the box in the top right corner. For news and research on specific brachytherapy options, you may search for "Mammosite," "Contura" or "SAVI." Future blogs will highlight news and research specific to the various treatment options. Please stay tuned.

Breast Brachytherapy in the News, Part 2: A Study on Mastectomy Rates and Side Effects

Today we continue our discussion of recent news on brachytherapy for breast cancer, with a focus on a 2011 San Antonio Breast Cancer Symposium presentation which generated some media headlines.

Background

Our last blog provided a brief overview of accelerated partial breast irradiation (APBI) and brachytherapy, including descriptions of the Mammosite (See photo, top), Contura Multi-Lumen Balloon (See photo, middle) and SAVI Applicator (See photo, bottom) brachytherapy systems.

For women with early-stage breast cancer, brachytherapy may be more convenient than external beam whole breast irradiation, but is it as effective? How does it compare in terms of side effects?

The MD Anderson study

A study presented at the 2011 San Antonio Breast Cancer Symposium in December addressed these questions. The results were covered by The New York Times, Medical News Today, Dr. Susan Love's blog, HealthImaging.com and The NCI Bulletin.

In the study, researchers from MD Anderson reviewed Medicare claims of over 130,000 women over age 66 who were diagnosed with breast cancer between 2000 and 2007. APBI use increased from 1% of patients in 2000 to 13% in 2007.

Four percent of the women treated with brachtherapy eventually had a mastectomy, compared to 2.2 percent of the women who were treated with whole breast irradiation. In addition, the risk of side effects, such as infection, breast pain, fat necrosis and rib fracture was higher in the brachytherapy group.

Study limitations

There are, however, some limitations to the study.

As reported by the NCI Bulletin on January 10, one of the lead researchers noted that the study was observational, had limited follow-up time and did not control for hormone therapy use.

According to HealthImaging.com (Dec. 15), other experts argue that Medicare records are an "inherently inaccurate database" in terms of tumor characteristics and prognostic markers. They note that women receiving APBI may have been "sicker" and therefore not candidates for several weeks of whole breast radiation.

They also question how side effects were measured and defined.

Moreover, they note that APBI delivery methods have improved since 2007.

There's also a question of whether a 4 percent mastectomy rate is clinically significant compared to a 2.2 percent rate. In her blog from the symposium, Dr. Susan Love made the following comment on the study,

"This sounded worrisome, until they said that the risk of needing a subsequent mastectomy was 4% with partial breast radiation and 2% in women with 6-week radiation. We will need to wait for the randomized data to mature to answer this question. At this point I don’t see a significant difference."

Additional research is ongoing

A large, randomized, phase III study sponsored by the National Cancer Institute comparing whole breast irradiation to APBI is currently underway. (Link to study protocol.) About half the women in the study will be treated with external whole beam irradiation. The other half will receive accelerated partial breast irradiation, either via one of two brachytherapy methods, or by 3-D conformal radiotherapy, an external form of APBI.

According to Dr. Thomas Julian, associate director of medical affairs for the National Surgical Adjuvant Breast and Bowel Project (NSABP), as quoted in the NCI Cancer Bulletin on January 10,

"We would certainly like to see people waiting for the trial data before broad implementation, but there is more than 10 years of partial-breast irradiation experience that shows that in low-risk women the recurrence outcomes are fairly good, comparable to what happens in low-risk patients who were treated with whole breast radiation. However, for higher-risk women, the data are just not available."

Patient selection

How are patients selected for brachytherapy? Part 3 of this blog will highlight a recent study in the Journal of the National Cancer Institute which looked at the use of brachytherapy in different patient populations. Please stay tuned.

Breast Brachytherapy in the News, Part 1: What is Brachytherapy?

Two recent studies on brachytherapy for breast cancer have attracted some media attention. This week, we'll share the latest research. Today, we'll start with some basic questions. What is accelerated partial breast irradiation? What is brachytherapy? How does brachytherapy differ from other methods of accelerated partial breast irradiation?

Accelerated Partial Breast Irradiation (APBI)

Traditionally, after a lumpectomy (breast conserving surgery), the entire breast is irradiated daily, for at least five weeks. The procedure is known as external beam whole breast irradiation (WBI).

Advances in technology have given rise to more convenient, more focused radiation options. For example, treatment duration can be shortened with accelerated hypofactionated whole breast radiation, which delivers higher doses of radiation over a shorter period of time, generally about three weeks. Another option, external beam partial breast irradiation, delivers radiation to a specific area of the breast, rather than the entire breast.

The term 'accelerated partial breast irradiation (APBI)' refers to treatment options that both shorten treatment time (accelerated) and treat a specific area of the breast (partial breast).

There are several different methods of APBI. For example, intraoperative radiotherapy treats the tumor cavity with radiation during surgery. The INTRABEAM sytem is a type of intraoperative radiotherapy. 3D conformal radiation therapy (3-D CRT), on the other hand, is a type of external beam APBI.

Brachytherapy

Brachytherapy refers to any APBI technique which supplies radiation directly to the tumor cavity within the breast after surgery. This is typically accomplished with the use of catheters containing radioactive seeds, like those pictured above. Treatment takes about a week.

There are several different types of brachytherapy.

Interstitial brachytherapy involves the insertion of several individual catheters for radiation delivery. (See image to the right.)

Several newer techniques involve one point of entry. For example, Mammosite (image below, left) and the Contura Multi-Lumen Balloon (image below, center) methods deliver radiation via an applicator with a balloon tip. After insertion through an incision, the balloon tip is "inflated" with a saline solution to fill the cavity the tumor occupied. A radioactive seed is sent to the balloon via a catheter system.

The SAVI Applicator (image below, right) delivers radiation via several catheters which are connected in a wisk-shaped device, which may open and close for ease of insertion.



Brachytherapy in the news

Two recent brachytherapy studies made headlines. Part 2 of this blog will focus on a presentation at the 2011 San Antonio Breast Cancer Symposium which compared mastectomy rates for brachytherapy and whole breast irradiation. Part 3 will highlight a study in the Journal of the National Cancer Institute which evaluated the use of brachytherapy in different patient populations.

Until then, links may be found on the brachytherapy page of our LATESTBreastCancer.com website. From the home page, click the Treatments tab, then search for 'brachytherapy' in the search box in the upper right corner.