Hypoxic modification of radiotherapy with nimorazole has in the DAHANCA 5 trial been shown to increase radiosensitivity in hypoxic head and neck squamous cell carcinomas (HNSCC).~Previously, it has not been possible to discriminate more hypoxic tumours from less hypoxic tumours. Thus, nimorazole has been added the radiotherapy of most HNSCC.~Recently, a hypoxia gene profile has been developed, that discriminate between more and less hypoxic tumours. The basis of the discrimination is the cumulated expression of 15 hypoxia responsive genes, quantified from the tumour biopsy.~The profile has been validated on the independent DAHANCA 5 cohort. There was a significant effect of adding nimorazole to the radiotherapy of more hypoxic tumours as estimated with the gene profile, whereas there was no effect of adding nimorazole to the less hypoxic tumours. In a test for interaction, there was a significantly different response to nimorazole in the more hypoxic tumours compared to the less hypoxic tumours.~In the Dahanca 30 trial it is aimed to verify, that there is no benefit of supplying the radiotherapy of less hypoxic HNSCC with nimorazole. Thus, to explore whether it is possible to avoid the sideeffects of nimorazole without risk for the patient.
Hypoxic modification of radiotherapy with nimorazole has previously been shown to increase radiosensitivity in hypoxic head and neck squamous cell carcinomas (HNSCC).~In Denmark, nimorazole is added the radiotherapy of most HNSCC, as it has not previously been possible to discriminate more hypoxic tumours from less hypoxic tumours.~A hypoxia gene profile has shown to discriminate between responders and non-responders to nimorazole.~In DAHANCA 30, expected hypoxia profile guided non-responders are randomized to +/- nimorazole during radiotherapy.This in order to verify clinical use of the gene profile in selecting the relevant patients for hypoxic modification of radiotherapy with nimorazole.