title: Breast cancer screening for childhood cancer survivors after craniospinal irradiation with protons versus x-rays: a dosimetric analysis and review of the literature.
abstract: BACKGROUND
  Screening for secondary malignancies is paramount in the pediatric cancer survivorship population, but the risk of secondary breast cancer after craniospinal radiation has not been well characterized previously. The aim of this study was to examine the dose to the breast from craniospinal irradiation (CSI) delivered with x-ray therapy versus proton beam therapy to contribute to understanding the specific screening needs of this population.
  
  
  METHODS
  Six female patients who received CSI with double-scattered proton therapy at the Children's Hospital of Philadelphia were identified. For each patient, photon and proton beam plans were designed in order to compare the radiation dose to the breast. A comprehensive literature review was also performed.
  
  
  RESULTS
  The dose to the breast tissues was near zero after proton therapy to the spine [average maximum and mean proton doses were 0.22 and 0.05 Gy(RBE), respectively]. In contrast, after photon treatment to the spine, average maximum and mean photon doses were 23 and 4 Gy, respectively (P<0.0001).
  
  
  CONCLUSIONS
  These data suggest that early screening for breast cancer may be unnecessary after CSI with proton beam therapy; however, after x-ray therapy, early breast cancer screening should be considered given doses to the breast that approach the Children's Oncology Group-recommended threshold.
authors.affiliation: Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia 10467, USA.
authors.forename: Rahul J
authors.initials: RJ
authors.lastname: Kumar
authors.forename: Huifang
authors.initials: H
authors.lastname: Zhai
authors.forename: Stefan
authors.initials: S
authors.lastname: Both
authors.forename: Zelig
authors.initials: Z
authors.lastname: Tochner
authors.forename: Robert
authors.initials: R
authors.lastname: Lustig
authors.forename: Christine
authors.initials: C
authors.lastname: Hill-Kayser
mesh_terms: D000293:Adolescent; D001943:Breast Neoplasms / Q000175:diagnosis*; D002648:Child; D061888:Craniospinal Irradiation / Q000009:adverse effects* / Q000379:methods*; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy; D009381:Neoplasms, Radiation-Induced / Q000175:diagnosis*; D061766:Proton Therapy / Q000009:adverse effects; D011874:Radiometry; D017741:Survivors