title: Five-year outcomes, cosmesis, and toxicity with 3-dimensional conformal external beam radiation therapy to deliver accelerated partial breast irradiation.
abstract: OBJECTIVE
  To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT).
  
  
  METHODS
  102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor.
  
  
  RESULTS
  The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P<.01). Late skin toxicity was no worse than grade 2 in either group, without significant differences between the 2 groups. In the ipsilateral breast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P<.05). Physician assessment showed that >75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups.
  
  
  CONCLUSIONS
  APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI.
authors.affiliation: Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona, Spain; Universidad Pompeu Fabra, Barcelona, Spain. Electronic address: nrodriguez@parcdesalutmar.cat.
authors.forename: Núria
authors.initials: N
authors.lastname: Rodríguez
authors.forename: Xavier
authors.initials: X
authors.lastname: Sanz
authors.forename: Josefa
authors.initials: J
authors.lastname: Dengra
authors.forename: Palmira
authors.initials: P
authors.lastname: Foro
authors.forename: Ismael
authors.initials: I
authors.lastname: Membrive
authors.forename: Anna
authors.initials: A
authors.lastname: Reig
authors.forename: Jaume
authors.initials: J
authors.lastname: Quera
authors.forename: Enric
authors.initials: E
authors.lastname: Fernández-Velilla
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Pera
authors.forename: Jackson
authors.initials: J
authors.lastname: Lio
authors.forename: Joan
authors.initials: J
authors.lastname: Lozano
authors.forename: Manuel
authors.initials: M
authors.lastname: Algara
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D004548:Elasticity / Q000528:radiation effects; D004954:Esthetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D058958:Organs at Risk / Q000528:radiation effects; D011832:Radiation Injuries / Q000473:pathology; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D012867:Skin / Q000473:pathology / Q000528:radiation effects; D015996:Survival Rate; D016896:Treatment Outcome; D047368:Tumor Burden