title: A prospective phase II study of magnetic resonance imaging guided hematopoietical bone marrow-sparing intensity-modulated radiotherapy with concurrent chemotherapy for rectal cancer.
abstract: OBJECTIVE
  To reduce acute hematologic toxicity (HT) in rectal cancer patients treated with neoadjuvant concurrent chemoradiotherapy by sparing the hematopoietical bone marrow (BM) indentified by magnetic resonance (MR).
  
  
  METHODS
  A total of 35 staged II/III rectal cancer patients were prospectively enrolled. MR images of pelvis were fused with the simulating CT images. Active BM indentified by MR was contoured as an organ at risk in the treatment plan. The neoadjuvant treatment regimen consisted of 50 Gy of radiation delivered in 25 fractions, 5 days per week, with concurrent daily capecitabine (1650 mg/m(2)/day, twice daily during RT course) and weekly oxiliplatin 50 mg/m(2)/qw. Multivariable linear regression model is used to test correlation between HT and dose-volume of BM.
  
  
  RESULTS
  Thirty-one patients (88.6%) had stage T3-4 disease, and 30 patients (85.7%) had node-positive disease. The median age of cohort was 55 years (range 28-73 years). Only 9 (25.7%), 6 (17.1%), 1 (2.9%) and 1 (2.9%) experienced acute Grade 2-4 leukopenia, neutropenia, anemia and thrombocytopenia, respectively. Multivariable linear regression revealed increased BM-V5 was significantly associated with decreased WBC nadirs (p = 0.005), decreased ANC nadirs (p = 0.002), and decreased PLT nadirs (p = 0.017). No dose-volume parameters of BM were found to be related with decreased Hb.
  
  
  CONCLUSIONS
  The irradiated volume of pelvic BM identified by MR is associated with HT in rectal cancer patients undergoing neoadjuvant concurrent chemoradiotherapy.
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Jianyang
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Yuan
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Tang
authors.initials: T
authors.lastname: Yuan
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Xin
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ning
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Ren
authors.initials: R
authors.lastname: Hua
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Hui
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yanru
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Shulian
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Song
authors.initials: S
authors.lastname: Yongwen
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Yueping
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Weihu
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yexiong
authors.affiliation: Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17 Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China. jingjin2015@163.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Jing
mesh_terms: D000328:Adult; D000368:Aged; D001853:Bone Marrow; D059248:Chemoradiotherapy; D005260:Female; D006410:Hematopoiesis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000628:therapy*
keywords: Bone marrow; Hematologic toxicity; Intensity-modulated radiation therapy; Magnetic resonance; Rectal cancer