MD's Dispute Study on Breast Cancer Brachytherapy

SAN FRANCISCO, (BUSINESS WIRE) -- A recent study on a sophisticated form of radiation treatment for breast cancer is inaccurate and has caused unnecessary concern among many patients, according to four top physician researchers.

Their target is a controversial study on breast brachytherapy, which is also known as accelerated partial breast irradiation (APBI). The data by some MD Anderson (MDA) Cancer Center researchers was presented at the recent San Antonio Breast Cancer Symposium.

The doctors challenged the data -- and reassured APBI patients -- during a press teleconference they organized to express their concerns about the study. The participating physicians included:

-- Robert Kuske, MD, (Scottsdale, AZ) Co-Principal Investigator, NSABP B-39 study comparing five-day APBI to six-week whole breast irradiation

-- Peter D. Beitsch, MD, FACS, (Dallas, TX) Co-Principal Investigator of the American Society of Breast Surgeons' MammoSite Registry

-- Jayant Vaidya, MD, (London, U.K.), pioneer of targeted intraoperative radiotherapy (IORT)

-- Rakesh Patel, MD, (Pleasanton, CA), Chairman, American Brachytherapy Society

The San Antonio abstract claimed an older form of APBI was associated with increased toxicity and higher rates of subsequent mastectomy in Medicare patients, compared with standard whole breast irradiation (WBI).

source: MarketWatch

Wayne State study finds soybean compounds enhances effects of cancer radiotherapy

Detroit - A Wayne State University researcher has shown that compounds found in soybeans can make radiation treatment of lung cancer tumors more effective while helping to preserve normal tissue.

A team led by Gilda Hillman, Ph.D., professor of radiation oncology at Wayne State University's School of Medicine and the Barbara Ann Karmanos Cancer Institute, had shown previously that soy isoflavones, a natural, nontoxic component of soybeans, increase the ability of radiation to kill cancer cells in prostate tumors by blocking DNA repair mechanisms and molecular survival pathways, which are turned on by the cancer cells to survive the damage radiation causes.

At the same time, isoflavones act to reduce damage caused by radiation to surrounding cells of normal, noncancerous tissue. This was shown in a clinical trial conducted at WSU and Karmanos for prostate cancer patients treated with radiotherapy and soy tablets.

In results published in the journal Nutrition and Cancer in 2010, those patients experienced reduced radiation toxicity to surrounding organs; fewer problems with incontinence and diarrhea; and better sexual organ function. Hillman's preclinical studies in the prostate tumor model led to the design of that clinical trial.

Soy isoflavones can make cancer cells more vulnerable to ionizing radiation by inhibiting survival pathways that are activated by radiation in cancer cells but not in normal cells. In normal tissues, soy isoflavones also can act as antioxidants, protecting those tissues from radiation-induced toxicity.

source: EurekAlert

Scientists may be able to double efficacy of radiation therapy

AUGUSTA, Ga. – Scientists may have a way to double the efficacy and reduce the side effects of radiation therapy.

Georgia Health Sciences University scientists have devised a way to reduce lung cancer cells' ability to repair the lethal double-strand DNA breaks caused by radiation therapy.

"Radiation is a great therapy – the problem is the side effects," said Dr. William S. Dynan, biochemist and Associate Director of Research and Chief, Nanomedicine and Gene Regulation at the GHSU Institute of Molecular Medicine and Genetics. "We think this is a way to get the same amount of cancer cell death with less radiation or use the same amount and maybe cure a patient that could not be cured before."

Radiation therapy capitalizes on radiation's ability to kill cells by causing double-strand breaks in DNA. But the fact that varying levels of radiation are essentially everywhere – food, air, the ground, etc. – means all cells, including cancer cells, have internal mechanisms to prevent the lethal breakage.

GHSU scientists are targeting the natural defense mechanisms by packaging a piece of an antibody against one of them with folate, which has easy access to most cells, particularly cancer cells. Many cancers, including the lung cancer cells they studied, have large numbers of folate receptors so that cancer cells get a disproportionate share of the package.

Previous efforts to destroy cancer cells' ability to avoid radiation damage have focused on receptors on their surface, said Dr. Shuyi Li, molecular biologist, pediatrician and corresponding author on the study in the International Journal of Radiation Oncology.

source: Georgia Health Sciences University

APBI Brachytherapy Associated with Higher Rate of Later Mastectomy, Increased Toxicities, and Post-Operative Complications, Compared to Traditional Radiation Therapy in Women with Early Breast Cancer

Accelerated partial breast irradiation (APBI) brachytherapy, the localized form of radiation therapy growing increasingly popular as a treatment choice for women with early-stage breast cancer, is associated with higher rate of later mastectomy, increased radiation-related toxicities and post-operative complications, compared to traditional whole breast irradiation (WBI), according to researchers from The University of Texas MD Anderson Cancer Center.

The retrospective study was presented in the CTRC-AACR San Antonio Breast Cancer Symposium's press briefing by Benjamin Smith, M.D., assistant professor in the Department of Radiation Oncology, and in the meeting's scientific session by Grace Smith, M.D., Ph.D., a resident in MD Anderson's Department of Radiation Oncology and the study's first author.

"Our study compared the two radiation therapy techniques available to women with early-stage breast cancer. We found that women treated with accelerated partial breast irradiation therapy have a two-fold increased risk for subsequent mastectomy, most likely because of tumor recurrence or local complications, as well as an increased risk for post-operative and radiation-related complications," said Ben Smith, the study's senior author.

There are numerous types of APBI; the MD Anderson study only looked at the brachytherapy technique, in which a form of radiation treatment involving insertion of a catheter containing a radioactive source to kill breast cancer cells that may remain after lumpectomy surgery.

source: MD Anderson

Elekta's Leksell Gamma Knife Perfexion Earns Nearly Perfect Score in 2011 KLAS Radiation Therapy Report

ATLANTA, Dec. 9, 2011 /PRNewswire/ -- With a score of 94.4 out of 100, Elekta's Leksell Gamma Knife® Perfexion™ is "practically perfect in every way," ranking at the top among six advanced radiation therapy systems, according to KLAS research firm's recently released customer survey, Radiation Therapy 2011: A Dose of New Technology. The Elekta Infinity™ radiation treatment system garnered the #2 ranking with a score of 84.4, improving its score over the 2010 report.

The 2011 KLAS report – the result of interviews with 213 U.S. provider organizations – referenced respondents' regard for the Perfexion system's technological sophistication, making "treating very complicated tumors in a difficult spot easy for providers," and for the radiosurgery platform's unprecedented uptime statistics. The report summarized customer opinion by noting: "The speed, accuracy, reliability, and sophistication of the treatments all came together for the Gamma Knife Perfexion to earn the highest score in the study by a 10-point margin."

Gamma Knife® surgery is a gentler alternative to traditional brain surgery for illnesses such as metastatic disease – cancer that has traveled to the brain from elsewhere in the body. The system delivers thousands of low-intensity radiation beams to one or more targets in a single session. Leksell Gamma Knife Perfexion provides even greater speed and ease of use than previous versions, especially for treating multiple metastases.

source: Elekta

Radiation Therapy for Breast Cancer: American Society of Breast Surgeons Responds to San Antonio Breast Cancer Symposium Data

n a study presented on 12/7/2011 at the San Antonio Breast Cancer Symposium (“Partial Breast Brachytherapy is Associated With Inferior Effectiveness and Increased Toxicity Compared to Whole Breast Irradiation in Older Patients”), physicians from the MD Anderson Cancer Center compared the 5-year results of accelerated partial breast irradiation (APBI) to whole-breast irradiation (WBI) in patients undergoing breast-conserving therapy. They observed higher rates of mastectomy (4% vs.2.2%) and of treatment-related complications in the APBI patients, differences which are statistically significant but small in absolute terms. The study comprises more than 130,000 patients' Medicare claims data, but is retrospective and therefore cannot assure that the ABPI and the WBI patients were comparable in all other ways. In addition, because this is a claims database, it cannot be concluded that the additional mastectomies were necessarily performed because of a recurrence of cancer.

The American Society of Breast Surgeons (ASBrS) maintains a registry of 1440 patients treated by APBI with the MammosSite® balloon catheter device through 2004, and in numerous publications has observed 1) a 5-year local recurrence rate of <5%, comparable to that of whole-breast radiation therapy, 2) a low rate of other complications, and 3) good or excellent cosmesis in approximately 90% of patients. Several single-institution randomized and nonrandomized studies using another technique of APBI, multiple interstitial catheters, also report rates of local recurrence comparable to WBI. source: PR Web

Varian Medical Systems Adds High Dose Delivery and Prone Breast Treatment Capabilities to Clinac® and Trilogy® Cancer Treatment Machines

PALO ALTO, Calif., Dec. 6, 2011 /PRNewswire/ -- Clinac® and Trilogy® medical linear accelerators from Varian Medical Systems (NYSE: VAR), machines that are used to treat cancer with targeted radiotherapy, have been updated to deliver higher doses up to two times faster than was previously possible. They can now also better facilitate treating breast cancer patients on their stomachs (in the prone position) rather than their backs—an approach that can reduce the volume of lung and heart tissue exposed to radiation during treatment. Updated control software, which received 510(k) clearance in November from the U.S. Food and Drug Administration (FDA), adds a High Intensity Mode to the Clinac and Trilogy machines, enabling dose delivery rates of up to 2400 monitor units per minute—double their former highest output.

"Our High Intensity Mode makes it possible to deliver some treatments up to 50 percent faster than is possible without it," said Chris Toth, senior director of marketing for Varian's Oncology Systems business. "We're seeing trends toward the use of hypo-fractionation and radiosurgical approaches for many types of cancer, which means that higher doses are delivered in just one or a few treatment sessions for quick ablation of a tumor. There has been encouraging research supporting this approach for the treatment of cancers of the brain[1], spine[2], and lung[3], as well as for prostate cancer.[4] With High Intensity Mode, our Clinac and Trilogy machines can deliver these high dose treatments within a clinically-feasible timeframe."

Varian also received FDA clearance for the Pivotal™ Care Solution for Prone Breast Treatment, an innovation that allows patients to be treated on their stomachs rather than their backs. Recent studies have shown that, for many women without axillary lymph node disease, treatment in the prone position can be used to significantly reduce the volume of lung and heart tissue exposed to the treatment beam.

source: Varian