Endometrial Cancer

Fast Facts:

• Most common gynecologic malignancy (1:50 women)
• Localized Disease: 5-year survival: 96%
• Distant Disease: 5-year survival: 17%

Normal Endometrial Uptake:    

Premenopausal: 

• While typically demonstrating little or no metabolic activity, even intense endometrial uptake is considered normal in the premenopausal woman (most intense near or during menstruation). 
• Unless the uptake is eccentric or accompanied by marked endometrial thickening and/or distention of the endometrial cavity, we presume such uptake is physiologic.

Postmenopausal:

• Any endometrial activity (focal or diffuse) above mediastinal blood pool uptake in a postmenopausal woman requires further assessment to exclude malignancy – even in the absence of an associated abnormality on the co-registered CT images.

Indications for PET/CT Scan: 

Screening & Diagnosis:  No current role for PET/CT.

Initial Staging: 

• While PET/CT may be of utility in the initial staging of select patients with a suspicion of advanced disease, surgical staging (with lymph node dissection) is still required.

Recurrence & Restaging: 

• PET/CT is utilized for patients with known or suspected recurrent disease (or at high risk for recurrence).
• PET/CT alters management in up to a third of patients with recurrent disease.
• Distinguishing recurrence from post-therapeutic inflammation.
• Recurrent Disease: Most commonly to the vagina, regional lymph nodes, peritoneal cavity and lungs.

Assessing Response to Therapy & Prognosis: 

• Early Response: Non-responders can be offered alternative therapy.
• Late Response: Assess success or failure of therapy, and ultimate outcome/prognosis.

Post-Therapy Surveillance:

• Some advocate PET/CT as the best means of following even asymptomatic patients after treatment.

What We Report:  

If the primary lesion is still present at the time of scanning, its metabolic activity and size (if measurable) are reported.  The size, SUV & location of representative metastatic lesions are also detailed. 

Primary Lesion:  

• Most endometrial cancer patients presenting for PET/CT imaging have already been surgically staged, so the primary lesion will have been resected. 
• If scanning is done prior to surgery, nearly every endometrial cancer will be readily identifiable by its intense metabolic activity (often accompanied by an enlarged/thickened endometrial cavity on the co-registered CT images).

Metastatic Disease: 

• Direct invasion of adjacent structure/organs.
• Seeding of peritoneal cavity.
• Lymphatic spread to pelvic and abdominal lymph nodes.
• Hematogenous spread, often to lungs, liver, and bone.

False Positives:

• Physiologic uptake in premenopausal women
• Submucosal uterine fibroid

False Negatives:

• Primary lesions < 8.0 mm (beneath the resolution of PET)
• Low-grade lesions
• Nodes or metastatic deposits < 8.0 mm