OPN plasma level detection in curative-intent radiotherapy of NSCLC might be of dual use: absolute pre-treatment OPN plasma levels, preferably in co-detection with other hypoxia-related proteins as part of a “hypoxic biomarker panel”, might help to identify patients with largely hypoxic, biologically aggressive and radioresistant tumors. Here, SPP1 is linked to non-small cell lung carcinoma.