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Phase 2 study of pre‐excision single‐dose intraoperative radiation therapy for early‐stage breast cancers
Author(s) -
VanderWalde Noam A.,
Jones Ellen L.,
Kimple Randall J.,
Moore Dominic T.,
KlauberDeMore Nancy,
Sartor Carolyn I.,
Ollila David W.
Publication year - 2013
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/cncr.27915
Subject(s) - medicine , lumpectomy , intraoperative radiation therapy , breast cancer , radiation therapy , mastectomy , breast conserving surgery , stage (stratigraphy) , cancer , surgery , radiology , nuclear medicine , paleontology , biology
BACKGROUND: Intraoperative radiation therapy (IORT) allows delivery of high‐dose radiation at the time of lumpectomy, potentially sparing adjuvant daily radiation. A phase 2 study of pre‐excision IORT was performed for early‐stage breast cancer. METHODS: Patients ≥ 48 years of age with invasive ductal carcinoma, ≤ 3 cm, and clinically node‐negative were eligible for this study, which was approved by institutional review board. Ultrasound was used to select electron energy and cone size to cover the tumor plus 1.5‐ to 2.0‐cm lateral margins and 1‐cm‐deep margins (90% isodose). Fifteen Gy was delivered with a Mobetron irradiator, and immediate needle‐localized partial mastectomy followed. Local event results were updated using the Kaplan‐Meier method. RESULTS: A total of 53 patients received IORT alone. Median age was 63 years, and median tumor size was 1.2 cm. Of these, 81% were positive for estrogen receptor or progesterone receptor, 11% were positive for human epidermal growth factor receptor 2, and 15% were triple‐negative. Also, 42%, 49%, and 9% would have fallen into the Suitable, Cautionary, and Unsuitable groups, respectively, of the American Society of Therapeutic Radiation Oncology consensus statement for accelerated partial breast irradiation. Median follow‐up was 69 months. Ipsilateral events occurred in 8 of 53 patients. The 6‐year actuarial rate of ipsilateral events was 15% (95% confidence interval = 7%‐29%). The crude event rate for Suitable and Cautionary groups was 1 of 22 (5%) and 7 of 26 (27%), respectively. Overall survival was 94.4%, and breast cancer–specific survival was 100%. CONCLUSIONS: The rate of local events in this study is a matter of concern, especially in the Cautionary group. On the basis of these findings, pre‐excision IORT, as delivered in this study, may not provide adequate local control for less favorable early‐stage breast cancers. Cancer 2013. © 2013 American Cancer Society.