title: Characteristics and kinetics of cervical lymph node regression after radiation therapy for human papillomavirus-associated oropharyngeal carcinoma: quantitative image analysis of post-radiotherapy response.
abstract: OBJECTIVE
  We sought to characterize the pattern of lymph node regression and morphology following definitive radiation therapy (RT) for human papilloma virus (HPV)-associated oropharyngeal carcinoma in patients with disease control.
  
  
  METHODS
  Radiographically positive cervical lymph nodes from patients treated with definitive RT for HPV-associated oropharyngeal carcinoma were segmented on initial pre- and subsequent post-RT contrast enhanced CT images. Pre-specified quantitative nodal parameters were calculated. Initial nodal parameter correlates of final nodal size, final nodal volume, and time to <1 cm short-axis diameter were determined.
  
  
  RESULTS
  Sixty-six radiographically positive lymph node were analyzed in 36 patients. Lymph nodes exhibited initial volume decreases with size stabilization at ∼4 months. Fifteen nodes (23%) underwent complete radiographic response (median 6.4 months following RT; range 2.9-25.6 months). On multivariate time-to-event analysis, initial hypodense/fat component, nodal volume, and short-axis diameter exhibited inverse association, while higher HU standard deviation exhibited a positive association, with reaching <1 cm short-axis diameter (all p<0.05).
  
  
  CONCLUSIONS
  Our results showed a substantial decrease in nodal volume within the first 1-2 months following RT. These findings support our current nodal imaging paradigm, propose a quantitative methodology, and describe a reference dataset for further validation and comparison studies.
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Chad
authors.initials: C
authors.lastname: Tang
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Clifton D
authors.initials: CD
authors.lastname: Fuller
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Garden
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Musaddiq J
authors.initials: MJ
authors.lastname: Awan
authors.affiliation: Departments of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Rivka R
authors.initials: RR
authors.lastname: Colen
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: William H
authors.initials: WH
authors.lastname: Morrison
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Frank
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Beth M
authors.initials: BM
authors.lastname: Beadle
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Jack
authors.initials: J
authors.lastname: Phan
authors.affiliation: Departments of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Erich M
authors.initials: EM
authors.lastname: Sturgis
authors.affiliation: Departments of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Zafereo
authors.affiliation: Departments of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Randal S
authors.initials: RS
authors.lastname: Weber
authors.affiliation: Departments of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: David I
authors.initials: DI
authors.lastname: Rosenthal
authors.affiliation: Departments of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. Electronic address: gbgunn@mdanderson.org.
authors.forename: G Brandon
authors.initials: GB
authors.lastname: Gunn
mesh_terms: D052685:Alphapapillomavirus / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D009959:Oropharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000821:virology; D014057:Tomography, X-Ray Computed
keywords: Cervical lymph nodes; HPV; Oropharynx cancer; Quantitative methodology; Radiographic response