title: A novel conformal superficial high-dose-rate brachytherapy device for the treatment of nonmelanoma skin cancer and keloids.
abstract: To develop a novel conformal superficial brachytherapy (CSBT) device as a treatment option for the patient-specific radiation therapy of conditions including superficial lesions, postsurgical positive margins, Dupuytren's contractures, keloid scars, and complex anatomic sites (eyelids, nose, ears, etc.).
  
  
  
  A preliminary CSBT device prototype was designed, built, and tested using readily available radioactive seeds. Iodine-125 (125I) seeds were independently guided to the treatment surface to conform to the target. Treatment planning was performed via BrachyVision Planning System (BPS) and dose distributions measured with Gafchromic EBT3 film. Percent depth dose curves and profiles for Praseodymium-142 (142Pr), and Strontium-90/Yttrium-90 (90Sr-90Y) were also investigated as potential sources. Results achieved with90Sr-90Y and electron external beam radiation therapy were compared and Monte Carlo N-Particle eXtended 2.6 simulations of142Pr seeds were validated.
  
  
  
  BPS was able to predict clinical dose distributions for a multiple seeds matrix. Calculated and measured doses for the125I seed matrix were 500 cGy and 473.5 cGy at 5 mm depth, and 171.0 cGy and 201.0 cGy at 10 mm depth, respectively. Results of90Sr-90Y tests demonstrate a more conformal dose than electron EBRT (1.6 mm compared to 4.3 mm penumbra). Measured142Pr doses were 500 cGy at surface and 17.4 cGy at 5 mm depth.
  
  
  
  The CSBT device provides a highly conformal dose to small surface areas. Commercially available BPS can be used for treatment planning, and Monte Carlo simulation can be used for plans using beta-emitting sources and complex anatomies. Various radionuclides may be used in this device to suit prescription depths and treatment areas.
authors.affiliation: Department of Radiation Oncology, University of Minnesota, Minneapolis, MN. Electronic address: cferreir@umn.edu.
authors.forename: Clara
authors.initials: C
authors.lastname: Ferreira
authors.affiliation: Department of Radiation Oncology, The University of Oklahoma, Oklahoma City, OK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Johnson
authors.affiliation: Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Karl
authors.initials: K
authors.lastname: Rasmussen
authors.affiliation: Department of Radiation Oncology, East Carolina University, Greenville, NC.
authors.forename: Clinton
authors.initials: C
authors.lastname: Leinweber
authors.affiliation: Department of Radiation Oncology, The University of Oklahoma, Oklahoma City, OK.
authors.forename: Salahuddin
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Department of Physics, East Carolina University, Greenville, NC.
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Jung
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D002280:Basal Cell Carcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D004867:Equipment Design; D006801:Humans; D007627:Keloid / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D009010:Monte Carlo Method; D011221:Praseodymium / Q000627:therapeutic use; D011868:Radioisotopes / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000295:instrumentation* / Q000379:methods; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D013326:Strontium Radioisotopes / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed; D015021:Yttrium Radioisotopes / Q000627:therapeutic use
chemical_list: D011868:Radioisotopes; D013326:Strontium Radioisotopes; D015021:Yttrium Radioisotopes; D011221:Praseodymium
keywords: Conformal superficial applicator; High-dose-rate brachytherapy; Monte Carlo simulation; Skin cancer