Long-Term Cancer Outcomes From Study NRG Oncology/RTOG 9517: A Phase 2 Study of Accelerated Partial Breast Irradiation With Multicatheter Brachytherapy After Lumpectomy for Early-Stage Breast Cancer

Int J Radiat Oncol Biol Phys. 2016 Aug 1;95(5):1460-1465. doi: 10.1016/j.ijrobp.2016.03.037. Epub 2016 Apr 2.


Purpose: To examine 10-year rates of local, regional, and distant recurrences, patterns of recurrence, and survival rates for breast cancer patients enrolled on Study NRG Oncology/Radiation Therapy Oncology Group 9517, a multi-institutional prospective trial that studied one of the earliest methods of accelerated partial breast irradiation (APBI), multicatheter brachytherapy (MCT).

Methods and materials: Eligibility included stage I/II unifocal breast cancer <3 cm in size after lumpectomy with negative surgical margins and 0 to 3 positive axillary nodes without extracapsular extension. The APBI dose delivered was 34 Gy in 10 twice-daily fractions over 5 days for high-dose-rate (HDR); and 45 Gy in 3.5 to 5 days for low-dose-rate (LDR) brachytherapy. The primary endpoint was HDR and LDR MCT reproducibility. This analysis focuses on long-term ipsilateral breast recurrence (IBR), contralateral breast cancer events (CBE), regional recurrence (RR), and distant metastases (DM), disease-free, and overall survival.

Results: The median follow-up was 12.1 years. One hundred patients were accrued from 1997 to 2000; 98 were evaluable; 65 underwent HDR and 33 LDR MCT. Median age was 62 years; 88% had T1 tumors; 81% were pN0. Seventy-seven percent were estrogen receptor and/or progesterone receptor positive; 33% received adjuvant chemotherapy and 64% antiendocrine therapy. There have been 4 isolated IBRs and 1 IBR with RR, for 5.2% 10-year IBR without DM. There was 1 isolated RR, 1 with IBR, and 1 with a CBE, for 3.1% 10-year RR without DM. The 10-year CBE rate was 4.2%, with 5 total events. Eleven patients have developed DM, 8 have died of breast cancer, and 22 have died from other causes. The 10-year DFS and OS rates are 69.8% and 78.0%, respectively.

Conclusion: This multi-institutional, phase 2 trial studying MCT-APBI continues to report durable in-breast cancer control rates with long-term follow-up.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Brachytherapy / mortality*
  • Brachytherapy / statistics & numerical data
  • Breast Neoplasms / mortality*
  • Breast Neoplasms / pathology
  • Breast Neoplasms / therapy*
  • Catheterization, Peripheral / mortality
  • Catheterization, Peripheral / statistics & numerical data
  • Combined Modality Therapy / mortality
  • Combined Modality Therapy / statistics & numerical data
  • Female
  • Humans
  • Longitudinal Studies
  • Mastectomy, Segmental / mortality*
  • Mastectomy, Segmental / statistics & numerical data
  • Middle Aged
  • Neoplasm Recurrence, Local / mortality*
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Recurrence, Local / prevention & control
  • Neoplasm Staging
  • Prevalence
  • Radiation Dose Hypofractionation*
  • Risk Factors
  • Survival Rate
  • Treatment Outcome
  • United States / epidemiology