National Trends for Intra-operative Radiation Therapy in Favorable, Early-stage Breast Cancer: A Propensity Scoring Analysis of the National Cancer Database

Mohamad Sebai, Beaumont Health
Muayad Almahariq, Beaumont Health
Joshua Dilworth, Beaumont Health
Patrick Kaabon
Rachel Kalthoff, Beaumont Health
Sayee Kiran, Beaumont Health
Jayant Vaidya
Sheldon Feldman
Nayan Dekhne, Beaumont Health


Background/Objective: Adjuvant whole breast irradiation (WBI) is recommended after breastconserving surgery for most patients with early-stage breast cancer. Recently, partial breast intraoperative radiotherapy (TARGIT-IORT), supported by randomised evidence, has emerged as a potential alternative treatment modality for suitable patients. IORT involves a single treatment at the time of lumpectomy, which is more convenient for the patient compared with 3-5 weeks of daily fractionated external beam WBI. We examined national trends regarding the use of IORT for breast cancer. Methods: We retrospectively reviewed the National Cancer Database (NCDB) and identified patients with clinical Stage I-III breast cancer who received breast-conserving surgery with either adjuvant WBI or IORT without adjuvant WBI between 2004-2014. Patient demographics, tumor characteristics, and survival were compared between the 2 groups. Univariate, multivariate, and stage-stratified propensity score weighted analyses were performed to compare study groups and survival. Results: We identified 2,871 (0.42%) eligible patients treated with TARGIT-IORT delivered at the time of the initial lumpectomy (“immediate”) and 675,429 (99.58%) patients treated with WBI. We excluded 141 patients treated with IORT during a procedure after the initial lumpectomy (“delayed”). Median follow-up was 54 months. The use of IORT significantly increased 16-fold in the 10 years from 0.07% in 2004 to 1.09% in 2014 (p