Predictive value of the tumor oxygenation by means of pO₂ histography in patients with advanced head and neck cancer

Purpose: The purpose of this analysis was to evaluate the potential of the tumor oxygenation by means of Eppendorf pO₂ histography as a predictive test to select patients for treatment alternatives. Patients and Methods: Pretreatment tumor pO₂ histographies of Locoregional lymph node metastases were assessed in 194 patients with squamous cell carcinoma of the head and neck. Included in the analysis were 134 patients who received a primary radio or radiochemotherapy with a radiation dose of ≥ 60 Gy, and who had no distant metastasis at beginning of the therapy. Results: The Cox regression analysis revealed the fraction of pO₂ values ≤ 2.5 mm Hg (p = 0.004), age (p = 0.04) and radiotherapy/radiochemotherapy (p = 0.03) as significant independent prognostic factors for the survival. The positive and negative predictive values were calculated using different cut-off values of the fraction of pO₂ values ≤ 2.5 mm Hg and the survival status at 1 or 2 years after beginning of the therapy as endpoint. The highest positive and negative predictive values of all cut-off values were 0.50 and 0.41 at 1 year, and 0.81 and 0.26 at 2 years. Conclusions: Our data confirm the influence of the tumor oxygenation on the prognosis of patients with squamous cell carcinoma of the head and neck after radiotherapy. However, the calculated positive and negative predictive values suggest that the pO₂ histography alone is not sufficient to be used as a predictive test to successfully select patients for treatment alternatives.