title: Fetal dose measurements and shielding efficiency assessment in a custom setup of (192)Ir brachytherapy for a pregnant woman with breast cancer.
abstract: OBJECTIVE
  To assess the radiation dose to the fetus of a pregnant patient undergoing high-dose-rate (HDR) (192)Ir interstitial breast brachytherapy, and to design a new patient setup and lead shielding technique that minimizes the fetal dose.
  
  
  METHODS
  Radiochromic films were placed between the slices of an anthropomorphic phantom modeling the patient. The pregnant woman was seated in a chair with the breast over a table and inside a leaded box. Dose variation as a function of distance from the implant volume as well as dose homogeneity within a representative slice of the fetal position was evaluated without and with shielding.
  
  
  RESULTS
  With shielding, the peripheral dose after a complete treatment ranged from 50 cGy at 5 cm from the caudal edge of the breast to <0.1 cGy at 30 cm. The shielding reduces absorbed dose by a factor of two near the breast and more than an order of magnitude beyond 20 cm. The dose is heterogeneous within a given axial plane, with variations from the central region within 50%. Interstitial HDR (192)Ir brachytherapy with breast shielding can be more advantageous than external-beam radiotherapy (EBRT) from a radiation protection point of view, as long as the distance to the uterine fundus is higher than about 10 cm. Furthermore, the weight of the shielding here proposed is notably lower than that needed in EBRT.
  
  
  CONCLUSIONS
  Shielded breast brachytherapy may benefit pregnant patients needing localized radiotherapy, especially during the early gestational ages when the fetus is more sensitive to ionizing radiation.
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain; Department of Atomic, Molecular and Nuclear Physics, University of Valencia, E-46100 Burjassot, Spain. Electronic address: ccanjuan@gmail.com.
authors: C
authors: C
authors: Candela-Juan
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain.
authors: J
authors: J
authors: Gimeno-Olmos
authors: National Dosimetry Centre, E-46009 Valencia, Spain.
authors: M C
authors: MC
authors: Pujades
authors: Department of Radiation Oncology, Tufts University School of Medicine, Boston, MA 02111, USA.
authors: M J
authors: MJ
authors: Rivard
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain.
authors: V
authors: V
authors: Carmona
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain.
authors: F
authors: F
authors: Lliso
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain.
authors: F
authors: F
authors: Celada
authors: Engineering Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain.
authors: J L
authors: JL
authors: Ramírez-Coves
authors: Department of Atomic, Molecular and Nuclear Physics, University of Valencia, E-46100 Burjassot, Spain.
authors: F
authors: F
authors: Ballester
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain.
authors: A
authors: A
authors: Tormo
authors: Radiotherapy Department, La Fe University and Polytechnic Hospital, E-46026 Valencia, Spain; Radiotherapy Department, Hospital Clínica Benidorm, E-03501 Benidorm, Spain.
authors: J
authors: J
authors: Perez-Calatayud
mesh_terms: D000328:Adult; D001918:Brachytherapy / Q000009:adverse effects / Q000295:instrumentation*; D001943:Breast Neoplasms / Q000532:radiotherapy*; D005260:Female; D005333:Fetus / Q000528:radiation effects*; D006801:Humans; D007496:Iridium Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000532:radiotherapy*; D011835:Radiation Protection / Q000295:instrumentation*; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted
chemical_list: D007496:Iridium Radioisotopes
keywords: Brachytherapy; Breast cancer; Fetal dose; Pregnant