If USC/Norris Comprehensive Cancer Center specialists have their way, certain women with breast cancer will be able to receive their entire course of radiation therapy in a single treatment—while still under anesthesia during surgery.
USC/Norris is participating in an international, multi-center clinical trial of intraoperative radiotherapy, a technique aimed at women with early stage invasive breast cancers who undergo breast-conserving surgery. The study is called the Targeted Intraoperative Radiotherapy Trial, or TARGIT.
“We believe intraoperative radiotherapy is a tremendous advancement in our ongoing effort to improve the quality of breast cancer treatment, as well as reduce the impact that these treatments have on women’s lives,” said breast surgeon Dennis R. Holmes, assistant professor of clinical surgery at the Keck School of Medicine.
Holmes is principal investigator on the trial at USC/Norris and is conducting the study with Oscar Streeter Jr., associate professor of radiation oncology at the Keck School.
Ordinarily, when physicians find invasive breast cancer early—and women have only a single, small tumor and no sign of cancer spread to the lymph nodes—the cancer may be effectively treated first through breast-conserving surgery, called a lumpectomy, and then through follow-up radiation therapy.
But radiation therapy through traditional external-beam radiation requires treatment five days a week for six to seven weeks at a medical center, which may be daunting for some women due to transportation limitations and family and job demands. Some women even opt to have a mastectomy rather than undergo the weeks of therapy.
“With intraoperative radiotherapy, radiation is administered during the surgical procedure, avoiding the need to return for additional radiotherapy later,” Holmes explained. “It only takes 20 to 35 minutes to administer, after the tumor has been removed.”
Here is how it works: A special wand featuring a round, gold tip is attached to the arm of a machine (called Intrabeam) next to the operating table. While the patient is still under anesthesia, physicians maneuver and manipulate the arm to position the gold tip inside the cavity left by her removed tumor. The wand accelerates electrons and shoots them through the gold tip, emitting X-rays exactly where they are needed: the tissues immediately surrounding the tumor, where the risk of cancer recurrence is greatest.
After the radiation is administered, surgeons close the incision as they normally would. Pathologists also check the tumor’s margins to ensure full removal of the tumor.
The TARGIT trial aims to find out if intraoperative radiotherapy is as effective as traditional external-beam radiation. Women will be randomly assigned to one of two groups: one receiving lumpectomy and intraoperative radiotherapy, and the other receiving lumpectomy and standard post-operative external-beam radiation.
Women may be eligible for the TARGIT trial at USC/Norris if they are age 40 or older, have a single invasive tumor three centimeters wide or smaller and have no positive lymph nodes. Intraoperative radiotherapy may be used in women regardless of breast size and for most small tumors regardless of their location in the breast.
Holmes said that even women who have already had a lumpectomy at USC/Norris or another medical center within the prior four weeks may be eligible. If chosen for intraoperative radiotherapy, they will undergo a second procedure at USC/Norris to insert the wand and administer radiation. If chosen for external-beam radiation, women may have it done at USC/Norris or at another hospital near their home.
Initial European studies indicate intraoperative therapy has similar side effects and effectiveness as external-beam radiation. Women must be willing to be monitored regularly after treatment. USC/Norris researchers aim to recruit 200 women for the trial. For more information on the TARGIT trial, visit www.targittrial.com or call (323) 865-3933.