title: Tumor progression in waiting time for radiotherapy in head and neck cancer.
abstract: BACKGROUND
  Waiting-time prior to radiotherapy is a well-known problem. This study aims to determine the impact of time on tumor growth in a patient population with squamous-cell carcinoma of the head and neck (SCCHN).
  
  
  METHODS
  In a consecutive cohort, all patients with both a diagnostic scan and a treatment-planning scan were identified. In total 648 patients were seen, and 414 treated with primary radiotherapy. Ninety-five had two scans and 61 sets were eligible for comparison. Endpoints were change in tumor volume, tumor volume doubling time (TVD) and disease progression measured by TNM-classification and RECIST criteria.
  
  
  RESULTS
  Median interval between eligible scans was 28 (5-95) days. Thirty-eight (62%) had measurable increase in tumor volume, median 46% (6-495%). For all patients TVD was median 99 days, but for the half of patients with fastest growing tumors TVD was 30 days (15-41). Tumor volume increase was significantly correlated to time and histological differentiation. Twelve (20%) developed new lymph-node metastasis and 10 (16%) progressed in TNM-classification. Evaluated by RECIST criteria 18 (30%) patients had progressive disease.
  
  
  CONCLUSIONS
  This study shows a negative impact of waiting time in patients with SCCHN. Within an average time of 4 weeks the majority of the patients developed significant signs of tumor progression. It was not possible to define a threshold for acceptable time intervals in order to avoid volume changes, or to define a subgroup that has no negative impact of delay.
authors.affiliation: Department of Experimental Clinical Oncology, Aarhus University Hospital, Nørrebrogade 44, Building 5, DK-8000 Aarhus C, Denmark. anni@oncology.dk
authors.forename: Anni Ravnsbaek
authors.initials: AR
authors.lastname: Jensen
authors.forename: Hanne Marie
authors.initials: HM
authors.lastname: Nellemann
authors.forename: Jens
authors.initials: J
authors.lastname: Overgaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D018450:Disease Progression; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D013997:Time Factors; D047368:Tumor Burden; D014850:Waiting Lists