title: Use of sequential endorectal US to predict the tumor response of preoperative chemoradiotherapy in rectal cancer.
abstract: OBJECTIVE
  Accurate prediction of the response to preoperative chemoradiotherapy (CRT) potentially assists in the individualized selection of treatment. Endorectal US (ERUS) is widely used for the pretreatment staging of rectal cancer, but its use for preoperatively predicting the effects of CRT is not well evaluated because of the inflammation, necrosis, and fibrosis induced by CRT. This study assessed the value of sequential ERUS in predicting the efficacy of preoperative CRT for locally advanced rectal cancer.
  
  
  METHODS
  Forty-one patients with clinical stage II/III rectal adenocarcinoma were enrolled prospectively. Radiotherapy was delivered to the pelvis with concurrent chemotherapy of capecitabine and oxaliplatin. Total mesorectal excision was performed 6 to 8 weeks later. EUS measurements of primary tumor maximum diameter were performed before (ERUS1), during (ERUS2), and 6 to 8 weeks after (ERUS3) CRT, and the ratios of these were calculated. Correlations between ERUS values, tumor regression grade (TRG), T down-staging rate, and pathologic complete response (pCR) rate were assessed, and survival was analyzed.
  
  
  RESULTS
  There was no significant correlation between ERUS2/ERUS1 and TRG. The value of ERUS3/ERUS1 correlated with pCR rate and TRG but not T down-staging rate. An ERUS3 value of 6.3 mm and ERUS3/ERUS1 of 52% were used as the cut-off for predicting pCR, and patients were divided into good and poor prognosis groups. Although not statistically significant, 3-year recurrence and survival rates of the good prognosis group were better than those of the poor prognosis group.
  
  
  CONCLUSIONS
  Sequential ERUS may predict therapeutic efficacy of preoperative CRT for locally advanced rectal cancer. (Clinical trial registration number: NCT01582750.).
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.affiliation: Department of Endoscopy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Lizhou
authors.initials: L
authors.lastname: Dou
authors.affiliation: Department of Endoscopy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.affiliation: Department of Endoscopy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Guiqi
authors.initials: G
authors.lastname: Wang
authors.affiliation: First Chest Radiotherapy Department, Hunan Cancer Hospital, Hunan, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Xiao
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yexiong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Ren
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Fang
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Weihu
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Shulian
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yueping
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Radiotherapy, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Yongwen
authors.initials: Y
authors.lastname: Song
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000069287:Capecitabine / Q000008:administration & dosage; D059248:Chemoradiotherapy; D013505:Digestive System Surgical Procedures; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D011379:Prognosis; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000069287:Capecitabine