• discriminatory value of MRI perfusion curve between tumoural and non-tumoural cervical lymph nodes [ Time Frame: preoperative ]
  MRI parameters will be considered validated if they enable differentiation between a metastatic cervical lymph node and a non-tumoural lymph node, as based on the final pathology report as the 'gold standard'
• discriminatory value of MRI ADC value between tumoural and non-tumoural cervical lymph nodes [ Time Frame: preoperative ]
  MRI parameters will be considered validated if they enable differentiation between a metastatic cervical lymph node and a non-tumoural lymph node, as based on the final pathology report as the 'gold standard'
• discriminatory value of MRI D value between tumoural and non-tumoural cervical lymph nodes [ Time Frame: preoperative ]
  MRI parameters will be considered validated if they enable differentiation between a metastatic cervical lymph node and a non-tumoural lymph node, as based on the final pathology report as the 'gold standard'

• discriminatory value of perfusion curve between bone invasion and no bone invasion [ Time Frame: preoperative ]
  MRI parameters will be considered validated if they enable differentiation between tumoural bone invasion and no bone invasion, as based on the final pathology report as the 'gold standard'
• discriminatory value of predefined perfusion curve between post-therapeutic sequelae and tumour relapse [ Time Frame: follow-up until 5 years postoperative ]
  MRI parameters will be considered validated if they enable differentiation between post-therapeutic sequelae and tumour relapse, as based on the final pathology report as the 'gold standard'
• predictive value of the MRI parameter Ktrans for treatment outcome [ Time Frame: end of adjuvant radiochemotherapy (approx 10 weeks postoperative) ]
  predictive value of MRI parameters for treatment outcome, measured through tumoural response at therapy end based on the RECIST criteria
• predictive value of predefined Ktrans for overall and disease-free survival [ Time Frame: postoperative follow-up at 3, 6, 12, 24, 36,48 and 60 months ]
  predictive value of MRI parameters for treatment outcome, measured through tumoural response at therapy end based on the RECIST criteria

• discriminatory value of perfusion curve between bone invasion and no bone invasion [ Time Frame: preoperative ]
  MRI parameters will be considered validated if they enable differentiation between tumoural bone invasion and no bone invasion, as based on the final pathology report as the 'gold standard'
• discriminatory value of predefined perfusion curve between post-therapeutic sequelae and tumour relapse [ Time Frame: follow-up until 5 years postoperative ]
  MRI parameters will be considered validated if they enable differentiation between post-therapeutic sequelae and tumour relapse, as based on the final pathology report as the 'gold standard'
• predictive value of the MRI parameter Ktrans for treatment outcome [ Time Frame: end of adjuvant radiochemotherapy (approx 10 weeks postoperative) ]
  predictive value of MRI parameters for treatment outcome, measured through tumoural response at therapy end based on the RECIST criteria
• predictive value of predefined Ktrans for overall and disease-free survival [ Time Frame: postoperative follow-up at 3, 6, 12, 24, 36,48 and 60 months ]

Background: The locoregional control rates in patients with advanced head and neck cancer remain suboptimal. Accurate diagnosis of metastatic cervical lymph nodes, bone invasion, or tumour relapse in a previously irradiated or operated field remains challenging. Technological advances in magnetic resonance imaging (MRI) enable to quantify diffusion and perfusion of the tumour and its surrounding tissues, which could improve diagnostic performance. Moreover, they could provide additional information about radiation and/or chemotherapeutic efficiency in an individual patient.

Objectives: The investigators aim to validate specific MRI parameters that could improve diagnostic accuracy of metastatic cervical lymph nodes in patients with a squamous cell carcinoma in the head and neck region. Moreover, we aim to explore specific MRI parameters that could improve diagnostic accuracy of bone invasion and tumour relapse, as well as predict treatment response and survival in this target population.

Methods: In this trial, a validation cohort will be recruited in a prospective manner, to validate the MRI parameters that showed clinically acceptable discriminant value based on the retrospective study. The values of the selected MRI parameters will be calculated in metastatic lymph nodes of the affected group, for comparison with their values measured in the lymph nodes of a prospectively recruited control group, comprising patients who require the same standardized MRI protocol for evaluation of a Whartin tumour or pleomorphic adenoma of the parotid gland without malignant transformation, and in whom both the parotid gland lesion and the cervical lymph node are surgically removed for histological confirmation. All included patients of the 'affected group' will also undergo a preoperative positron emission tomography-computed tomography (PET-CT), according to international guidelines, and will preferably receive a multiparametric MRI at 3, 6, 12, 24, 36, 48 and 60 months post treatment as part of routine follow-up.

Histopathologically proven SCC in the HN region (affected group)

- Histopathologically proven Whartin tumour or pleomorphic adenoma in the HN region without malignant transformation (control group)

• Head and Neck Cancer
• Multiparametric MRI
• Cervical Lymph Node
• Bone Invasion
• Tumour Relapse
• Treatment Response

• affected
  All patients with a histologically confirmed squamous cell carcinoma in the head and neck region
• control
  Whartin tumour or pleomorphic adenoma of the parotid gland without malignant transformation

Inclusion Criteria:

• Patients who received a pretreatment multiparametric MRI according to a standardized protocol
• Histopathologically proven SCC in the HN region (affected group)
• Histopathologically proven Whartin tumour or pleomorphic adenoma in the HN region without malignant transformation (control group)
• Patients in whom a or multiple clearly distinguishable cervical lymph node(s) can be observed radiologically, and which can be correlated unambiguously with the pathology report

Exclusion Criteria:

• not fulfilling abovementioned criteria
• thyroid or skin cancer
• considerable artefact on MRI
• previously surgery, irradiation or chemotherapy in the HN region