title: Long-Term Update of NRG Oncology RTOG 0319: A Phase 1 and 2 Trial to Evaluate 3-Dimensional Conformal Radiation Therapy Confined to the Region of the Lumpectomy Cavity for Stage I and II Breast Carcinoma.
abstract: NRG Oncology RTOG 0319 was the first cooperative group trial in the United States to evaluate 3-dimensional conformal radiation therapy (3D-CRT) accelerated partial breast irradiation (APBI). This report updates secondary endpoints of toxicity and efficacy.
  
  
  
  Patients with stage I or II invasive breast cancer (tumor size ≤3 cm, ≤3 positive lymph nodes, negative margins) were eligible for 3D-CRT APBI: 38.5 Gy in 10 twice-daily fractions. Patient characteristics and treatment details have previously been reported. Adverse events were graded with CTCAE v3.0 (National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0). This analysis updates the rates of ipsilateral breast recurrence (IBR), contralateral breast recurrence, ipsilateral node recurrence (INR), metastatic sites (distant metastases [DM]), mastectomy, disease-free survival, mastectomy-free survival, and overall survival.
  
  
  
  Of 58 enrolled patients, 52 were eligible, with a median age of 61 years; 94% had stage I cancer and 83% had estrogen receptor positive disease. The median follow-up period was 8 years (minimum-maximum, 1.7-9.0 years). The 7-year estimate of isolated IBR (no DM) was 5.9%. The 7-year estimates of all IBRs, INR, mastectomy rate, and DM were 7.7%, 5.8%, 7.7%, and 7.7%, respectively. All 4 IBRs were invasive, of which 3 had a component within the planning target volume. The patterns of failure were as follows: 3 IBRs, 1 INR, 2 DM, 1 INR plus DM, and 1 IBR plus INR plus DM. The 7-year estimates of mastectomy-free survival, disease-free survival, and overall survival were 71.2%, 71.2%, and 78.8%, respectively. Thirteen patients died: 3 of breast cancer and 10 of other causes. Grade 3 (G3) treatment-related adverse events were reported by 4 patients (7.7%). No G3 pain or pulmonary or cardiac toxicities were reported.
  
  
  
  This phase 1 and 2 trial of 3D-CRT APBI continues to show durable tumor control and minimal G3 toxicity, comparable to other APBI techniques. Mature phase 3 results will determine the appropriateness and limitations of this noninvasive APBI technique.
authors.affiliation: Radiation Oncology, University of Colorado Denver, Aurora, Colorado. Electronic address: rachel.rabinovitch@ucdenver.edu.
authors.forename: Rachel
authors.initials: R
authors.lastname: Rabinovitch
authors.affiliation: NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Moughan
authors.affiliation: Radiation Oncology, St Joseph Mercy Oakland, Pontiac, Michigan.
authors.forename: Frank
authors.initials: F
authors.lastname: Vicini
authors.affiliation: Surgery, Stamford Hospital, Stamford, Connecticut.
authors.forename: Helen
authors.initials: H
authors.lastname: Pass
authors.affiliation: Medical Physics, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: John
authors.initials: J
authors.lastname: Wong
authors.affiliation: Radiation Oncology, Cross Cancer Institute, Edmonton, Alberta, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Chafe
authors.affiliation: Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ivy
authors.initials: I
authors.lastname: Petersen
authors.affiliation: Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Arthur
authors.affiliation: Radiation Oncology, The Ohio State University Medical Center, Columbus, Ohio.
authors.forename: Julia
authors.initials: J
authors.lastname: White
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D000072662:Margins of Excision; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011832:Radiation Injuries; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D047368:Tumor Burden; D000069584:Unilateral Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D014481:United States