Delahaut G, et al. - Because when a patient is seen with a newly diagnosed oropharyngeal squamous cell carcinoma, it remains unclear to the treating physicians how fast the rate of tumor growth is, researchers determined the prognostic impact of tumor growth velocity in radiotherapy-treated squamous cell carcinoma of the head and neck. They selected comparable diagnostic CT-scan (DiCT) and radiotherapy planning CT-scan (RtCT) from patients with oropharynx squamous cell carcinoma treated by radiotherapy. To calculate tumor progression, tumor and pathological lymph node volumes were measured. The mean absolute tumor progression rate was 0.23 ± 0.2 cm³/d and mean relative progression rate was 1.84 ± 1.64%/d from the selection of 19 patients. Findings suggested that the progression of tumors can be evaluated on the basis of DiCT and RtCT. Treatment delay at all costs should be avoided. Different patterns of growth have been shown. Pejorative clinical outcomes have been suggested for the rapidly growing tumors subgroup. In order to confirm a link between fast-growing tumors and increased risk of recurrence, prospective studies are required.