title: Responsiveness of experimental prostate carcinoma bone tumors to neutron or photon radiation combined with cytokine therapy.
abstract: OBJECTIVE
  To improve the outcome of radiotherapy for prostate carcinoma bone tumors, we investigated bone tumor irradiation with photons or neutrons followed by interleukin 2 (IL-2) therapy in a tumor model.
  
  
  METHODS
  Implantation of PC-3 cells in nude mouse femur cavity induced a bone tumor that progressed to the formation of a palpable tumor, at the hip joint, by Day 20. Established bone tumors were irradiated with photons or neutrons, and a day later, mice were treated with IL-2 therapy for 3 weekly cycles.
  
  
  RESULTS
  PC-3 bone tumors responded to radiation with photons or neutrons in a dose-dependent manner. Combination of photon or neutron radiation with IL-2 therapy increased tumor growth delay, compared to that with photons or neutrons alone. Radiation alone or combined with IL-2 significantly increased mouse survival compared to that with IL-2 or no treatment. After combined therapy, a complete inhibition of bone tumor growth was observed in 45% to 50% of the mice. Histologically, the combined therapy resulted in greater tumor destruction associated with fibrosis, new bone formation, and inflammatory infiltrates than that observed with each modality alone.
  
  
  CONCLUSIONS
  The efficacy of tumor irradiation with neutrons or photons was enhanced by IL-2 therapy for the treatment of prostate carcinoma bone tumors.
authors.affiliation: Department of Radiation Oncology, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine and Harper Hospital, Detroit, MI 48201, USA. hilmang@karmanos.org
authors.forename: Gilda G
authors.initials: GG
authors.lastname: Hillman
authors.forename: Richard L
authors.initials: RL
authors.lastname: Maughan
authors.forename: David J
authors.initials: DJ
authors.lastname: Grignon
authors.forename: Mark
authors.initials: M
authors.lastname: Yudelev
authors.forename: Mingxin
authors.initials: M
authors.lastname: Che
authors.forename: Judith
authors.initials: J
authors.lastname: Abrams
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Andrey
authors.initials: A
authors.lastname: Layer
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Wright
authors.forename: Johanna
authors.initials: J
authors.lastname: Rubio
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Forman
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy; D006801:Humans; D007376:Interleukin-2 / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009502:Neutrons / Q000627:therapeutic use*; D017785:Photons / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000628:therapy*; D014407:Tumor Cells, Cultured
chemical_list: D007376:Interleukin-2