Five-year results of a prospective clinical trial investigating accelerated partial breast irradiation using 3D conformal radiotherapy after lumpectomy for early stage breast cancer.
BACKGROUND
Accelerated partial breast irradiation (APBI) is emerging as an alternative to whole-breast irradiation. This study presents the results of a prospective trial evaluating 3-dimensional conformal radiotherapy (3D-CRT) to deliver APBI for early-stage breast cancer.


METHODS
Patients with unifocal stage 0-II breast cancer measuring ≤2.5 cm without lymph node involvement were eligible. After lumpectomy, 3D-CRT APBI was delivered to the lumpectomy cavity + margin (34-38.5 Gy in 10 fractions over 5 days).


RESULTS
141 patients with 143 breast cancers (2 bilateral) were treated with 3D-CRT APBI. Median age was 60. Median tumor size was 1.1 cm. At a median follow up of 60 months (range, 5-113), the 5-year and 8-year cumulative incidence rate of a true recurrence is 0.9%. The 5-year and 8-year cumulative incidence rates of an elsewhere failure are 2.4% and 4.4%, respectively. The 5-year and 8-year overall survival is 100% and 94%, respectively. Among the 62 patients with follow up >5 years, 95% had excellent/good cosmetic results.


CONCLUSIONS
Our experience with 3D-CRT APBI demonstrates excellent cosmesis and local control. Longer follow up will be necessary to evaluate long-term efficacy and toxicity of 3D-CRT APBI. CLINICALTRIALS.
NCT00185744.
Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA. Electronic address: kateh@stanford.edu.
Kathleen C
KC
Horst
Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA.
Carolina
C
Fasola
Department of Radiology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA.
Debra
D
Ikeda
Department of Radiology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA.
Bruce
B
Daniel
Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA.
Grant
G
Ognibene
Department of Radiation Oncology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA.
Don R
DR
Goffinet
Department of Surgery, Division of Surgical Oncology, Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA 94305, USA.
Frederick M
FM
Dirbas
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology* / Q000628:therapy*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000628:therapy*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology / Q000628:therapy*; D018275:Carcinoma, Lobular / Q000473:pathology / Q000628:therapy*; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009367:Neoplasm Staging; D011446:Prospective Studies; D020266:Radiotherapy, Conformal / Q000379:methods*; D015996:Survival Rate; D047368:Tumor Burden
3D conformal external beam radiotherapy (3D-CRT); Accelerated partial breast irradiation (APBI); Breast cancer; Breast-conserving therapy; Margin