title: Bone marrow sparing in intensity modulated proton therapy for cervical cancer: Efficacy and robustness under range and setup uncertainties.
abstract: OBJECTIVE
  This study evaluates the potential efficacy and robustness of functional bone marrow sparing (BMS) using intensity-modulated proton therapy (IMPT) for cervical cancer, with the goal of reducing hematologic toxicity.
  
  
  METHODS
  IMPT plans with prescription dose of 45 Gy were generated for ten patients who have received BMS intensity-modulated X-ray therapy (IMRT). Functional bone marrow was identified by (18)F-flourothymidine positron emission tomography. IMPT plans were designed to minimize the volume of functional bone marrow receiving 5-40 Gy while maintaining similar target coverage and healthy organ sparing as IMRT. IMPT robustness was analyzed with ±3% range uncertainty errors and/or ±3 mm translational setup errors in all three principal dimensions.
  
  
  RESULTS
  In the static scenario, the median dose volume reductions for functional bone marrow by IMPT were: 32% for V(5Gy), 47% for V(10Gy), 54% for V(20Gy), and 57% for V(40Gy), all with p<0.01 compared to IMRT. With assumed errors, even the worst-case reductions by IMPT were: 23% for V(5Gy), 37% for V(10Gy), 41% for V(20Gy), and 39% for V(40Gy), all with p<0.01.
  
  
  CONCLUSIONS
  The potential sparing of functional bone marrow by IMPT for cervical cancer is significant and robust under realistic systematic range uncertainties and clinically relevant setup errors.
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Dinges
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Felderman
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA; Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: McGuire
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA.
authors.forename: Brandie
authors.initials: B
authors.lastname: Gross
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA; Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, USA.
authors.forename: Sudershan
authors.initials: S
authors.lastname: Bhatia
authors.affiliation: Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Mott
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA; Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, USA.
authors.forename: John
authors.initials: J
authors.lastname: Buatti
authors.affiliation: Department of Radiation Oncology, University of Iowa, USA; Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, USA. Electronic address: dongxu-wang@uiowa.edu.
authors.forename: Dongxu
authors.initials: D
authors.lastname: Wang
mesh_terms: D001853:Bone Marrow / Q000528:radiation effects*; D005260:Female; D006801:Humans; D061766:Proton Therapy / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D035501:Uncertainty; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy*
keywords: Bone marrow sparing; Cervical cancer; Proton; Robustness