Intraoperative Radiotherapy as a Boost During Breast-Conserving Surgery Using Low-Kilovoltage X-Rays: The First 5 Years of Experience With a Novel Approach
Received 30 April 2009; received in revised form 19 June 2009; accepted 23 June 2009. published online 25 January 2010.
Purpose
Intraoperative radiotherapy (IORT) during breast-conserving surgery (BCS) has been recently introduced using different devices. We report the first 5 years of a single-center experience after introduction of a novel approach to deliver IORT as a tumor bed boost during BCS for breast cancer.
Methods and Materials
A total of 155 breast cancers in 154 women (median age, 63 years; range, 30–83 years; T1/T2 = 100/55; N0/N+ = 108/47) were treated between February 2002 and December 2007 at the University Medical Center Mannheim, in whom IORT as tumor bed boost was applied using 50-kV X-rays (20 Gy) followed by 46–50 Gy whole-breast external-beam radiotherapy (EBRT). Chemotherapy, if indicated, was given before EBRT. The median interval between BCS plus IORT and EBRT was 40 days. Median follow-up was 34 months (maximum 80 months, 1 patient lost to follow-up). Overall survival and local relapse-free survival were calculated at 5 years using the Kaplan-Meier method. Seventy-nine patients were evaluated at 3-year follow-up for late toxicity according to the Late Effects in Normal Tissues–Subjective, Objective, Management, and Analytic system.
Results
Ten patients died, 2 had in-breast relapse, and 8 developed distant metastases (5-year overall survival = 87.0%; 5-year local relapse-free survival = 98.5%). Grade 3 fibroses of the tumor bed were detected in 5% of the patients after 3 years. Skin toxicity was mild (telangiectases and hyperpigmentations in approximately 6% each).
Conclusions
Intraoperative radiotherapy as a tumor bed boost during BCS for breast cancer using low-kilovoltage X-rays followed by EBRT yields low recurrence and toxicity rates.
∗Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
†Department of Obstetrics and Gynecology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
Reprint requests to: Frederik Wenz, M.D., Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer Ufer 1-3, 68167 Mannheim, Germany. Tel: (+49) 621-383-4960; Fax: (+49) 621-383-733496
Supported by grants from the Bundesministeriums für Bildung und Forschung and the Dietmar Hopp Stiftung.
Conflict of interest: Radiobiologic research in the laboratory of F. Wenz is supported by Carl Zeiss Oberkochen.
ABSTRACT