Welcome to Our Blog
Thank you for visiting our website. We are a relatively small lab with big ideas. We are part of a much larger group of investigators known collectively as the LLUMC Molecular Radiation Biology Laboratories. It is our hope that this website will educate, communicate, and incite scientific debate. As the PI of our little group, I hope to post our data and discuss potential mechanisms, consequences, and countermeasures. With a bit of luck we'll all learn something. The links to the left include our merry band as well as collaborating investigators and laboratories. The links to the right include our archive and blogroll. The banner above will always bring you back to the main page page. Take a look around and please feel free to leave a comment on our blog (try to keep it civil and constructive) or shoot us an e-mail. - Michael " Ubertramp " Pecaut
ASTRO: Proton Radiation Linked to Lower Risk of Second Malignancy
Posted by: Ubertramp on 2008.09.27
Categories & Tags: Cancer Risk,Protons,Radiation,Radiotherapy,Secondary Malignancies,Society Meeting
Comments: None
This just in: .
BOSTON, Sept. 22 — Proton therapy may cut the risk of a second malignancy by half compared with conventional radiation treatment, results of a retrospective comparison suggested.
Almost 13% of patients treated with photon energy developed second malignancies compared with 6.4% of those treated with proton-based radiation, Nancy Tarbell, M.D., of Harvard, reported at the American Society for Therapeutic Radiology and Oncology meeting here.
The rest of the article can be found here. I still can’t get a link to the actual paper or abstract, though.
Protons, Secondary Neutrons, and Cancer
Posted by: Ubertramp on
Categories & Tags: Cancer Risk,Neutrons,New Publication,Protons,Radiation,Radiotherapy,Secondary Radiation
Comments: None
There has been some controversy about secondary neutrons during proton therapy and the risk of cancer. Here’s a recent paper which suggests the risk is very small, but not negligible, and dependent on age.
Int J Radiat Oncol Biol Phys. 2008 Sep 1;72(1):228-35. Epub 2008 Jun 18.
Risk of developing second cancer from neutron dose in proton therapy as function of field characteristics, organ, and patient age.
Zacharatou Jarlskog C, Paganetti H.
Department of Radiation Oncology, Copenhagen University Hospital, Copenhagen, Denmark.
PURPOSE: To estimate the risk of a second malignancy after treatment of a primary brain cancer using passive scattered proton beam therapy. The focus was on the cancer risk caused by neutrons outside the treatment volume and the dependency on the patient’s age. METHODS AND MATERIALS: Organ-specific neutron-equivalent doses previously calculated for eight different proton therapy brain fields were considered. Organ-specific models were applied to assess the risk of developing solid cancers and leukemia. RESULTS: The main contributors (>80%) to the neutron-induced risk are neutrons generated in the treatment head. Treatment volume can influence the risk by up to a factor of approximately 2. Young patients are subject to significantly greater risks than are adult patients because of the geometric differences and age dependency of the risk models. Breast cancer should be the main concern for females. For males, the risks of lung cancer, leukemia, and thyroid cancer were significant for pediatric patients. In contrast, leukemia was the leading risk for an adult. Most lifetime risks were <1% (70-Gy treatment). The only exceptions were breast, thyroid, and lung cancer for females. For female thyroid cancer, the treatment risk can exceed the baseline risk. CONCLUSION: The risk of developing a second malignancy from neutrons from proton beam therapy of a brain lesion is small (i.e., presumably outweighed by the therapeutic benefit) but not negligible (i.e., potentially greater than the baseline risk). The patient’s age at treatment plays a major role.
