Navigation Links
Normal tissue not spared in new forms of breast cancer radiotherapy
Date:10/30/2007

JACKSONVILLE, Fla. − A five day course of radiotherapy to treat breast cancer may, in some cases, expose as much lung and heart tissue to potentially toxic radiation as does the standard six weeks of treatment, say researchers at Mayo Clinic Jacksonville.

That because the short treatment, known as partial breast irradiation, focus radiation to a small sector of the breast through multiple beams, these beams can pass through the breast to the heart and lungs that lie behind, researchers found. Radiating the entire breast over weeks, as is standard practice, can expose much of the heart and lungs to long periods of lower dose radiation, they say.

These findings, presented at the annual meeting of the American Society for Therapeutic Radiation and Oncology (ASTRO), suggest that both methods carry risks and benefits that may be equivalent, says the studys lead investigator, Laura Vallow, M.D.

This tells us that the standard course of therapy isnt that bad in terms of its exposure to normal tissue, but also that, sometimes, partial breast irradiation may not spare as much normal tissue as we hope, Vallow says.

Oncologists are currently testing the two modes of radiotherapy − whole breast irradiation (WBI) and 3-D conformal partial breast irradiation (PBI) − in a large federally-supported clinical trial that is enrolling thousands of women across the country who have been diagnosed with early stage breast cancer and have undergone lumpectomy.

The hope is that a short course of radiotherapy will be as effective as the much longer course, and that this could lead to increased use of breast conservation over mastectomy, Vallow says. Many women may be opting for a mastectomy instead of a lumpectomy in order to avoid weeks and weeks of radiation treatment, she says. If the results of both methods are equivalent, then perhaps some of these women will choose less drastic surgery.

In two studies being presented at ASTRO, Vallow, along with Ashley Gale, M.S., Anudh Jain, M.D., and a team of physicists at Mayo Clinic Jacksonville, used radiological parameters that were prepared for patients in the clinical trial and employed computers to assess how much of normal heart and lung tissue would be exposed if either WBI or PBI were used.

We suspect there are fundamental differences in the amount of exposure to radiation a patient has using these techniques, but no one has ever looked at how much normal tissue is spared, she says. We are interested in the finer points of treatment planning, with the ultimate goal of making treatment more tolerable with less radiation exposure.

In the first study, the researchers analyzed radiation plans for 25 patients enrolled in the clinical trial and they calculated what radiation to the lung would be if WBI or PBI was used. They found that PBI exposes a slightly larger volume of the lung to low doses of radiation, but also exposes a smaller volume of lung to high doses than WBI does.

Patients are getting more exposure overall to their lungs with partial breast irradiation but less lung tissue is irradiated to higher doses compared to whole breast irradiation, Vallow says.

For 14 of the same patients who had a lumpectomy in their left breast, investigators calculated radiation to normal heart tissue. They found that PBI and WBI delivered about the same amount of radiation to the heart of patients whose tumor was located in the middle of the breast. In patients whose tumors were closer to the armpit, PBI did not affect normal heart tissue, Vallow says.

This study shows how far we have really come in the delivery of radiotherapy, she says. We are looking for nuances of tissue exposure.


'/>"/>

Contact: Kevin Punsky
punsky.kevin@mayo.edu
904-953-2299
Mayo Clinic
Source:Eurekalert

Related medicine news :

1. Obese children may have abnormalities of lipoproteins
2. Inflammatory bowel disease linked to genetic abnormality
3. Anti-Cancer Drug Restores Normal Cell Growth
4. Dyslexia due to cerebellum abnormality
5. Cleft lip and palate are due to abnormality in brain structure
6. Early Detection Of Facial Abnormalities in a Fetus
7. Abnormal Brain Structure One Of The Reasons For Depression in Adolescents
8. Antidepressants Could Lead To Abnormal Bleeding
9. Test for prenatal chromosomal abnormalities using cervical swab
10. People with abnormal heart rhythms must avoid fish oil
11. Normal Blood Pressure Could Add Over 5 Years To Your Life
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/27/2017)... ... 2017 , ... Elisa Guajardo Carothers is not your typical author. She went from working as ... Now, she writes about God, when she isn’t swimming as a performing mermaid. , Her ... BS! (Before Satan),” she offers a comedic look at the dysfunctions of God’s family, before ...
(Date:2/27/2017)... (PRWEB) , ... February 27, 2017 , ... POUGHKEEPSIE, N. ... ) has disclosed that despite scientific studies, the Center for Disease Control ( CDC ... Lyme disease . Kenneth B. Liegner, M.D. has compiled into a single volume ...
(Date:2/27/2017)... ... February 27, 2017 , ... ... and environs, is proud to announce an upgrade to the company's Yelp listing. ... Yelp page on topics as diverse as Platelet Rich Plasma (PRP) therapy, hair ...
(Date:2/26/2017)... ... February 26, 2017 , ... This ... became the world’s first to be ISO/IEC 17025:2005 INAB accredited for Der p ... ISO/IEC 17025:2005 is the globally recognised standard that sets out requirements for the ...
(Date:2/26/2017)... ... February 26, 2017 , ... ... new technology standard in staffing, scheduling, and reporting for healthcare organizations. This ... activity throughout the entire staffing process. StaffBridge technology improves staffing efficiency, maximizes ...
Breaking Medicine News(10 mins):
(Date:2/24/2017)... 23, 2017 Report analyzes the worldwide markets for ... analytics for the US, Canada , ... Asia-Pacific , Latin America , ... for the period 2015 through 2022. Also, a six-year historic ... are derived from primary and secondary research. Company profiles are ...
(Date:2/24/2017)... ITL Limited, ( ASX : ITD ), une société de ... excellents résultats semestriels clos le 31 décembre 2016 par ... « Résultats et mise à jour sur la croissance biomédicale ... Faits marquants Bénéfice ... hausse de 104 %) Bénéfice par action ...
(Date:2/24/2017)... -- This report analyzes the worldwide markets for Chiral Technology ... Products: Intermediates, Analytical, and Others. The End Use markets ... The report provides separate comprehensive analytics for the US, ... , and Rest of World. Annual estimates and forecasts ... a six-year historic analysis is provided for these markets. ...
Breaking Medicine Technology: