This prospective interventional study evaluates the predictive value of tumor mutational burden, liquid biopsy biomarkers (including circulating tumor DNA), angiogenic factors, and dynamic contrast-enhanced magnetic resonance (MR) perfusion imaging in patients with HPV-negative oropharyngeal squamous cell carcinoma treated with concurrent chemoradiotherapy. The aim is to improve prediction of treatment response and disease course after treatment, support decision-making regarding optimal therapy, and potentially reduce the number of imaging examinations required during follow-up.

Patients with HPV-negative oropharyngeal squamous cell carcinoma treated with standard concurrent chemoradiotherapy are prospectively included in this study. The study investigates tumor mutational burden and specific somatic mutations in tumor tissue, as well as circulating tumor DNA (ctDNA) and other molecular biomarkers obtained through liquid biopsy. In addition, angiogenic factors in plasma and microRNA in extracellular vesicles are analyzed and compared with quantitative parameters obtained from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) perfusion.

The main objective is to gain additional insight into tumor biology during and after chemoradiotherapy and to identify prognostic and predictive biomarkers associated with treatment response and disease progression. The study also aims to assess whether biomarker-based monitoring may reduce the need for repeated imaging examinations while maintaining accurate evaluation of treatment response and follow-up.

Inclusion Criteria:

• Age ≥ 18 years
• Histologically confirmed HPV-negative oropharyngeal squamous cell carcinoma
• Planned treatment with concurrent chemoradiotherapy
• Ability to undergo MRI examination
• Signed informed consent

Exclusion Criteria:

• HPV-positive oropharyngeal carcinoma
• Contraindications for MRI
• Severe comorbidities preventing chemoradiotherapy
• Pregnancy or breastfeeding
• Inability to comply with study procedures