title: Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy.
abstract: Gross target volume of primary tumor (GTV-P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma (NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity-modulated radiotherapy (IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to find a suitable cut-off value of GTV-P for prognosis prediction.
  
  
  
  Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver operating characteristic (ROC) curves were used to identify the cut-off values of GTV-P for the prediction of different endpoints [overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS)] and to test the prognostic value of GTV-P when compared with that of the American Joint Committee on Cancer T staging system.
  
  
  
  The 358 patients with locally advanced NPC were divided into two groups by the cut-off value of GTV-P as determined using ROC curves: 219 (61.2%) patients with GTV-P ≤46.4 mL and 139 (38.8%) with GTV-P >46.4 mL. The 3-year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV-P ≤46.4 mL than in those with GTV-P > 46.4 mL (all P < 0.05). Multivariate analysis indicated that GTV-P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve verified that the predictive ability of GTV-P was superior to that of T category (P < 0.001). The cut-off values of GTV-P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively.
  
  
  
  In patients with locally advanced NPC, GTV-P >46.4 mL is an independent unfavorable prognostic indicator for survival after IMRT, with a prognostic value superior to that of T category.
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: He
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Hematology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, P. R. China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Cao
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Ya-Jie
authors.initials: YJ
authors.lastname: Zhao
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Zi-Jian
authors.initials: ZJ
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, P. R. China.
authors.forename: Deng-Ming
authors.initials: DM
authors.lastname: Chen
authors.affiliation: School of Public Health, Central South University, Changsha, Hunan, 410008, P. R. China.
authors.forename: Tu-Bao
authors.initials: TB
authors.lastname: Yang
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Xin-Qiong
authors.initials: XQ
authors.lastname: Huang
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Qin
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China.
authors.forename: You-Yi
authors.initials: YY
authors.lastname: Dai
authors.affiliation: Department of Oncology, Xiangya Hospital, Central South University, No. 87, Xiangya Road, Changsha, Hunan, 410008, P. R. China. lfshen2008@163.com.
authors.forename: Liang-Fang
authors.initials: LF
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology* / Q000532:radiotherapy; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000532:radiotherapy; D009367:Neoplasm Staging; D011379:Prognosis; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies; D015996:Survival Rate; D047368:Tumor Burden; D055815:Young Adult
keywords: Gross target volume of primary tumor; Intensity-modulated radiotherapy; Nasopharyngeal carcinoma; Prognosis