title: Partial breast irradiation delivered with proton beam: results of a phase II trial.
abstract: OBJECTIVE
  A phase II trial sought to determine the safety and efficacy of proton beam irradiation to deliver partial breast radiotherapy after lumpectomy for early-stage breast cancer.
  
  
  METHODS
  Eligible patients included women with invasive nonlobular carcinoma ≤ 3 cm. Surgical therapy included lumpectomy with negative margins and negative axillary lymph nodes on sampling. Postoperative proton radiotherapy to the surgical bed with an additional 1-cm margin was delivered by 40 Gy in 10 fractions over a 2-week course. Patients received systemic therapy as recommended after proton treatment. Patients had clinical evaluations every 6 months and annual mammograms.
  
  
  RESULTS
  Fifty patients were enrolled; median follow-up was 48 months. All patients completed the prescribed treatment. Acute toxicities were limited to mild radiation dermatitis. Late skin toxicities included 3 grade 1 telangiectasias. There were no posttreatment infections or ulcerations and no cases of fat necrosis, rib fractures, radiation pneumonitis, or cardiac events. Actuarial 5-year overall survival and disease-free survival rates were 96% and 92%, respectively. No local failures occurred. Ipsilateral breast cancer developed in 1 patient 5.5 years after treatment. Dose-volume histogram analysis showed near-complete elimination of dose to the contralateral breast, lung, and heart.
  
  
  CONCLUSIONS
  Proton partial breast radiotherapy appeared to be a feasible method of treatment and provided excellent disease control within the ipsilateral breast. Treatment-related toxicity was minimal and no technical limitations prevented treatment delivery. The incidence of posttreatment complications may be less than that reported when using more invasive techniques; comparative trials should be considered.
authors: Department of Radiation Medicine, Loma Linda University Medical Center, 11234 Anderson Street, Loma Linda, CA 92354, USA. SCTeichm@llu.edu
authors: David A
authors: DA
authors: Bush
authors: Jerry D
authors: JD
authors: Slater
authors: Carlos
authors: C
authors: Garberoglio
authors: Sharon
authors: S
authors: Do
authors: Sharon
authors: S
authors: Lum
authors: James M
authors: JM
authors: Slater
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D009367:Neoplasm Staging; D061766:Proton Therapy; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone