title: [Relationship of gross tumor volume with lymph node metastasis and prognosis of esophageal carcinoma].
abstract: OBJECTIVE
  To explore whether there is a relationship between gross tumor volume (GTV) and pathologic lymph node metastasis or prognosis of esophageal carcinoma, and to provide a new prognosis reference for esophageal carcinoma (EC).
  
  
  METHODS
  Six hundred and seven patients received radical resection of thoracic esophageal carcinoma from May 2002 to June 2006 in our hospital, and their pre-operative CT images were transmitted to the three-dimensional conformal radiotherapy planning system by the network in digital format. Esophageal GTV targets were outlined and their GTV volumes were calculated. To analyze whether there is a relationship between GTV volume and pathologic lymph node metastasis or prognosis.
  
  
  RESULTS
  In the 607 cases of esophageal carcinoma, the GTV volume was (22.5 ± 16.8) cm(3) in 374 stage N0 EC patients, significantly different from that of (30.4 ± 20.1) cm(3) in 233 stage N1 EC cases (P < 0.001). There is a significant difference between the GTV volumes of the groups with and without lymph node metastasis (P < 0.05). There was a significant difference of the GTV volumes of EC patients with one lymph node metastasis and those with ≥ 4 lymph node metastasis (P < 0.05). There was a positive correlation between GTV volume and the number of lymph node metastasis (r = 0.230, P < 0.001). The 1-, 3-, 5-year survival rates since the surgery date were 83.8%, 53.5%, and 36.4%, respectively. There was a significant difference between the survival rates of stage N0 (48.5%) and stage N1 patients (18.2%, P < 0.001), and there was a significant difference between the survival rats of patients with 0, 1 and ≥ 2 lymph node metastasis (P < 0.01). Cox regression model analysis showed that GTV volume, number of lymph node metastasis, pathological type, and lesion site were independent prognostic factors (all P < 0.05).
  
  
  CONCLUSIONS
  The GTV volume of esophageal carcinoma is positively correlated with the number of pathologic lymph node metastasis, and it is an independent prognostic factor for this cancer.
authors.affiliation: Department of CT Imaging, the Fourth Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.forename: Zhi-kun
authors.initials: ZK
authors.lastname: Liu
authors.forename: Yan-kun
authors.initials: YK
authors.lastname: Cao
authors.forename: You-mei
authors.initials: YM
authors.lastname: Li
authors.forename: Shu-chai
authors.initials: SC
authors.lastname: Zhu
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D016629:Esophagectomy / Q000379:methods; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D020266:Radiotherapy, Conformal; D015996:Survival Rate; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden