PET/MRI in Oropharyngeal Squamous Cell Carcinoma Evaluation

Head and neck cancer (HNC) continues to be a significant health care problem in Taiwan and oropharyngeal squamous cell carcinoma (SCC) is the common subtype. With the concern of organ preservation in recent years, concurrent chemoradiation is the major treatment modality for oropharyngeal SCC. Endoscopy with biopsy serve as the main diagnostic tools in patients with oropharyngeal SCC. While computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used to evaluate the tumor extent of HNC, MRI is more preferred in the oropharyngeal area by virtue of its high contrast resolution. With the advance of MRI technology, whole body MRI is now possible, and functional techniques become more feasible in the head and neck region, including diffusion-weighted imaging (DWI) which comprises of monoexponential DWI, IVIM (intravoxel incoherent motion) model and Kurtosis (biexponential or non-Gaussian fitting), and perfusion-weighted imaging (PWI) become feasible. Therefore, MRI can evaluate distant site status of HNC in the single examination session and provide biologic information of tumors, such as cellularity, angiogenesis and permeability, and so forth. Positron emission tomography/CT (PET/CT) is another common imaging modality to evaluate HNC, because of its ability to provide whole-body anatomic and metabolic information. Integrated PET/MRI is a novel imaging technology that combines PET and MRI in one single scanner. It can acquire both PET and MRI information simultaneously. Initial data convey that PET/MRI performed favorably in diagnostic evaluation of HNC. However, the predictive value of PET/MRI in treatment outcome of HNC has not been reported. A prospective study of integrated PET/MRI in a large cohort of patients with specific tumor origin and uniform treatment protocol is needed to fully validate the clinical usefulness of this novel integrated system. In this 3-year prospective study, the investigators will take the advantages of integrated PET/MRI scanner with diffusion-weighted MRI (DWI) and dynamic contrast-enhanced perfusion weighted MRI (DCE-PWI) to evaluate our 160 patients with oropharyngeal SCC subjected to chemoradiation. Non-contrast chest CT will also be performed on the same day. The investigators aim to (1) determine whole-body staging/restaging accurately, (2) predict treatment response and prognosis, and (3) to determine necessity of noncontrast chest CT. The investigators expect that this project will offer the validation of usefulness of integrated PET/MRI in tumor staging/restaging of oropharyngeal SCC and resultant clinical impact. The role of noncontrast chest in the workup with our PET/MRI protocol can be defined. It will also provide evidence about how and to what extent the various simultaneously acquired MRI and PET functional parameters can help prediction of treatment response and prognosis, which are important in timely modification of treatment regimen.

Sex

All

Minimum age

20 Years

Maximum age

80 Years

Inclusion Criteria:

* histologically proven oropharyngeal SCC subjected to chemoradiation

Exclusion Criteria:

* Exclusion criteria include previous head or neck malignant tumor, a second malignant tumor, distant metastasis, contraindications to MRI (renal insufficiency, cochlear implant, cardiac pacemaker placement or intracranial aneurysmal ferromagnetic clips), and serum glucose level \>200 mg/dl.