title: Can radiological changes in lymph node volume during treatment predict success of radiation therapy in patients with locally advanced head and neck squamous cell carcinoma?
abstract: BACKGROUND
  Assessment of nodal response after radiotherapy (RT) for head and neck squamous cell carcinoma is difficult, as both CT and positron emission tomography scanning have limited predictive value for residual disease. We sought to measure changes in nodal volume during RT to determine whether such changes are predictive of nodal disease control.
  
  
  METHODS
  Patients with locally advanced head and neck squamous cell carcinoma treated with 70 Gy of radical RT (±chemotherapy or anti-epidermal growth factor receptor (EGFR) antibodies) were eligible. Baseline pre-RT scans and cone-beam CT scans done at the outset of treatment and at weeks 3, 5 and 7 (cone-beam CTs # 1, 2, 3 and 4, respectively) were deformably coregistered, and 3D nodal volumes were measured.
  
  
  RESULTS
  Thirty-eight eligible patients were identified. The main primary tumour site was oropharyngeal; most patients had stage IVa disease. Twenty-seven patients received concurrent platinum-based chemotherapy, 10 received only an EGFR inhibitor with RT and one received RT alone. Twelve patients had a failure in the neck. After week 1 of treatment, a 4% mean decrease in nodal volume was observed, increasing to 40% at week 7. Platinum-based chemotherapy achieved significantly greater decreases in nodal volume than EGFR inhibitors (44 vs. 25%; P = 0.026). Advanced tumour stage predicted neck failure (P = 0.002), but nodal volumes did not correlate with neck control.
  
  
  CONCLUSIONS
  Changes in nodal volume are minimal initially during RT but accelerate during the latter weeks of therapy. This study suggests that chemotherapy achieves a greater decrease in nodal volume than EGFR inhibitors and that nodal changes do not predict disease control in the neck.
authors.affiliation: Division of Radiation Oncology, London Health Sciences Centre, London, Ontario, Canada.
authors.forename: Sanju
authors.initials: S
authors.lastname: Mishra
authors.forename: Alexander
authors.initials: A
authors.lastname: Hammond
authors.forename: Nancy
authors.initials: N
authors.lastname: Read
authors.forename: Varagur
authors.initials: V
authors.lastname: Venkatesan
authors.forename: Eric
authors.initials: E
authors.lastname: Winquist
authors.forename: Anthony
authors.initials: A
authors.lastname: Nichols
authors.forename: Andrew
authors.initials: A
authors.lastname: Warner
authors.forename: David
authors.initials: D
authors.lastname: Palma
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000077195:Squamous Cell Carcinoma of Head and Neck; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: chemotherapy; head and neck neoplasm; lymph node; predictive factor; radiotherapy