Intraoperative radiotherapy as a boost during breast-conserving surgery using low-kilovoltage X-rays: the first 5 years of experience with a novel approach.
OBJECTIVE
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
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.
Wenz
Frederik
F
Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany. frederik.wenz@medma.uni-heidelberg.de
Welzel
Grit
G
Blank
Elena
E
Hermann
Brigitte
B
Steil
Volker
V
Sütterlin
Marc
M
Kraus-Tiefenbacher
Uta
U
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001940:Breast / Q000473:pathology / Q000528:radiation effects; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D005355:Fibrosis / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D009367:Neoplasm Staging; D011446:Prospective Studies; D011859:Radiography; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D049291:Seroma / Q000000981:diagnostic imaging