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The Lancet Oncology

Showing posts with label radiation. Show all posts
Showing posts with label radiation. Show all posts

Monday, September 14, 2009

Particle Beam Radiation Therapy Promising but Unproven for Treating Cancer

Particle beam radiation therapy, a technology used to treat several types of cancer, is considered by some clinicians to be better than traditional radiation, but there is limited evidence about its safety compared with other types of radiation therapy, according to a new comparative effectiveness report funded by the Department of Health & Human Services' (HHS) Agency for Healthcare Research and Quality (AHRQ)."

As technologies develop and new clinical interventions arise, it is important to balance access to potentially beneficial new technologies with ongoing research and evaluation to determine whether the technologies deliver what they promise," said AHRQ Director Carolyn M. Clancy, M.D. "Increased funding for comparative effectiveness research is an exciting opportunity to continue important research on medical therapies and interventions."

Particle beam radiation therapy, also known as charged particle radiation therapy or proton beam radiation therapy, uses beams of protons or other charged particles for cancer radiation treatment. This therapy is an alternative to other types of cancer radiation therapy such as external radiotherapy with ionizing photon (X- or gamma-ray) beams or brachytherapy with implanted radioactive sources.

All types of radiation therapy can harm both cancerous and healthy tissues, so clinicians strive to target the radiation to the cancer while avoiding adjacent healthy tissues. This is particularly important for tumors adjacent to critical body parts such as those in the eye, brain, head and neck. Particle beam radiation therapy can target the radiation with a high degree of precision, but its potential advantages over other radiotherapy alternatives have not been verified in long-term outcome studies, according to the new AHRQ technical brief.

Particle beam radiation therapy was introduced as an experimental treatment in the 1950s but was not cleared for widespread use by the U.S. Food and Drug Administration until 2001. The technology is very expensive—an estimated $175 million for each device—and is usually only available in large academic medical centers. Only seven centers in the United States currently provide the therapy, with an additional center currently under construction and expected to be operational by 2010. Although details have not been disclosed, several other hospitals are considering developing smaller treatment facilities based on upcoming technologies that have not yet been cleared by the Food and Drug Administration.

The technical brief did not indicate that particle beam radiation therapy is riskier than conventional radiation therapy. However, most studies about the therapy were conducted on small numbers of patients and did not compare the safety of particle beam radiation therapy against other therapies. For many cancers other than head and neck cancers, there are not enough comparative studies in the literature to base an evaluation of the clinical or cost effectiveness of particle beam radiation therapy compared with other treatments.

AHRQ is currently reviewing scientific studies on radiation therapies for head and neck cancers that will evaluate the clinical effectiveness of particle beam radiation therapy for those cancers.

The report is the Agency's first in a series of technical briefs—rapid-turnaround reports that summarize key issues regarding emerging treatments. Technical briefs highlight where more research is needed and where research may be sufficient to warrant a full systematic review. Technical briefs are produced by AHRQ's Effective Health Care program. Future technical briefs will describe the evidence on fetal surgery, stereotactic surgery for non-brain cancers and percutaneous heart valves.

AHRQ's new report, Technical Brief: Particle Beam Radiation Therapies for Cancer, is the newest research review from the Agency's Effective Health Care program. That program, authorized by the Medicare Prescription Drug, Improvement and Modernization Act, represents an important federal effort to compare alternative treatments for health conditions and make the findings public. The program is intended to help patients, doctors, nurses, pharmacists and others choose the most effective treatments.

Thursday, December 4, 2008

Breast Cancer Treatment Offers Better Outcome to Women with Implants

Women with early-stage breast cancer who have undergone breast augmentation may be treated successfully with a partial-breast radiation treatment called brachytherapy, according to a study presented at the 94th Scientific Assembly and Annual Meeting (November 30 – December 5, 2008) of the Radiological Society of North America (RSNA) on Monday. Patients treated with brachytherapy have better cosmetic outcomes and avoid the risk of the implant hardening, compared to patients who undergo whole-breast radiation therapy.

"We are seeing an increasing number of breast cancer patients with augmentation,” explained Robert R. Kuske Jr., M.D., clinical professor at the University of Arizona Health Sciences Center (AHSC) and radiation oncologist at Arizona Oncology Services (AOS) in Scottsdale, Arizona. “By nature, these women are concerned about their appearance and we need to have options for them."

According to the American Society of Plastic Surgeons, breast augmentation is the most popular cosmetic surgery in the U.S. with 347,500 procedures performed in 2007. This represents an increase of 64 percent since 2000. Approximately one in eight women who undergo breast augmentation will develop breast cancer at some point in their lives.

The most common breast cancer treatment for patients with breast implants is skin-sparing mastectomy and implant exchange. Whole-breast radiation therapy after lumpectomy is an option, but carries a substantial risk during the healing process of scar tissue wrapping around the implant, causing it to become rock-hard and extremely painful. This condition, known as capsular contracture, also distorts the appearance of the breast.

Dr. Kuske set out to determine if partial-breast radiation with brachytherapy might offer a better outcome for women with implants wishing to avoid mastectomy.

Breast brachytherapy is a radiation treatment that can be given in higher doses to a small, targeted area of the breast after lumpectomy. Radioactive “seeds” are guided into place through small plastic tubes, or catheters, with the aid of imaging and a computer. The seeds emit high doses of radiation in short bursts.

Scar tissue is minimal, the implant remains unaffected and treatment time is shortened from 6.5 weeks with whole-breast radiation therapy to five days with brachytherapy.

For the study, 65 women who were diagnosed with small, early stage malignant tumors were treated with brachytherapy after a lumpectomy. The women received two doses per day, separated by six hours, over a five-day period. Follow-up was six months to five years. None of the patients experienced tumor recurrence during the follow-up period. Cosmetic outcome was determined to be good to excellent in 100 percent of patients with 95 percent judged excellent. Implant hardening was not observed in any of the patients.

"Compared to traditional treatments, brachytherapy offers an excellent alternative for these women," Dr. Kuske said. "It offers very high rates of tumor control with fewer side effects and is easier on their lifestyle."

Brachytherapy at a Glance
  • Can successfully treat early-stage breast cancer in women with implants and preserve the breast's appearance.
  • Substantially reduces the risk of implant hardening.
  • Approximately one in eight women who undergo breast augmentation will develop breast cancer during her lifetime.

Click here to read the abstract (Breast Brachytherapy Improves Cosmetic Outcome and Reduces the Risk of Capsular Contracture in Breast Conservation Therapy for Women with Breast Cancer in the Presence of Augmentation Mammoplasty)