Repeatability and prognostic impact of the pretreatment pO(2) histography in patients with advanced head and neck cancer

Purpose: The purpose of this study was to evaluate the repeatability and th e predictive relevance of the pretreatment pO(2) histography on the surviva l of patients with advanced head and neck cancer. Patients and methods: From July 1995 to August 1998, polarographic pO2 meas urements of lymph node metastases before therapy were performed in altogeth er 60 patients with histologically proven squamous cell carcinoma of the he ad and neck using the Eppendorf histograph. Forty-one of 60 patients were t reated with an accelerated-hyperfractionated radiotherapy regimen with or w ithout simultaneous chemotherapy as part of a multicenter phase III study. In 23 of 60 patients, two repeated independent measurements of the same tum or were performed with a time interval of approximately 24 h between the tw o measurements. Results: The multivariate analysis revealed the fraction of pO(2) values le ss than or equal to2.5 mmHg as the only significant prognostic factor for t he survival (P = 0.05) in the 41 study patients. No correlation was found b etween tumour oxygenation and the volume of the measured lymph node metasta ses or the haemoglobin concentration. The coefficient of variation of the r epeated measurements representing the assay variability was 57-68% of the t otal variation. Conclusion: Our data support the concept of the relevance of the pretreatme nt tumour hypoxia for the prognosis of patients with head and neck cancer a fter fractionated radiotherapy. Because of the relative poor repeatability of the pO(2) histography and the small patient number, further studies are required to confirm this finding and to evaluate the most relevant oxygenat ion parameter for clinical endpoints. (C) 2000 Elsevier Science Ireland Ltd . All rights reserved.