The standard treatment for cervix cancer at Princess Margaret Hospital is external radiation with chemotherapy followed by internal radiation, called brachytherapy. Currently, brachytherapy treatment is planned on a type of Magnetic Resonance Imaging (MRI) called T2-weighted (T2W) MRI.

The main purpose of this study is to determine whether the following imaging tests can visualize the tumor better for planning the brachytherapy treatment:

1. special types of MRI called diffusion weighted MRI (DWI) and dynamic-contrast enhanced MRI (DCE-MRI); and
2. an x-ray test called positron emission test (PET) performed with a sugar dye called FDG. MRI-guided brachytherapy is resource-intensive and not widely available.

Inclusion Criteria:

1. Age ≥ 18 years
2. Histologic diagnosis of squamous cell carcinoma, adenocarcinoma or adenosquamous carcinoma of the cervix
3. FIGO Stage IB - IVA
4. Intention to treat using radiotherapy with or without concurrent cisplatin chemotherapy according to the current treatment policies of the PMH Gynecology Group
5. Intention to treat with MR-guided brachytherapy as part of standard radiotherapy according to the current treatment policies of the PMH Gynecology Group
6. No cytotoxic anti-cancer therapy for cervix cancer prior to study entry
7. A negative urine or serum pregnancy test within the two week interval immediately prior to the first PET-CT imaging, in women of child-bearing age
8. Ability to provide written informed consent to participate in the study

Exclusion Criteria:

1. Prior complete or partial hysterectomy
2. Carcinoma of the cervical stump
3. Inability to lie supine for more than 30 minutes
4. Insulin-dependent diabetes mellitus
5. Impaired kidney function with glomerular filtration rate < 30
6. Previous anaphylactic reaction to gadolinium or other contraindications to MR.