Ovarian cancer accounts for nearly 3% of all cancers among women and ranks second among the gynecological cancers, following cancer of the uterus. The American Cancer Society estimates that there will be 22,000 new cases of ovarian cancer in the United States each year, and an estimated 15,000 deaths. Ovarian cancer causes more deaths than any other cancer of the female reproductive system.
Source: American Cancer Society. Cancer Facts & Figures 2011. Atlanta: American Cancer Society; 2011
Ovarian Cancer Diagnosis
Only a small number of ovarian cancers are found at an early stage because early cancers of the ovary often have no symptoms, and tumors on the ovary cannot usually be found through usual screening tests like the Pap test. For diagnosis of ovarian cancer there is a great deal of promise in the use of serum markers, and possibly anatomical imaging such as ultrasound for patients with elevated serum markers. Currently, ovarian cancer is difficult for even skilled doctors to find and diagnose at its earliest stage, and usually all patients suspected to harbor a primary ovarian carcinoma will undergo laparotomy.
PET/CT scanning can help the physician in detecting metastatic disease and determining the stage of the cancer immediately after it is found so that the most appropriate therapy can be given.
Early determination of how far the ovarian cancer has spread is the key to selecting the most appropriate treatment.
Ovarian Cancer Treatment
Treatment options include surgery, chemotherapy and occasionally radiation therapy. Surgery usually involves removal of one or both ovaries, fallopian tubes and the uterus. In younger women with early stage tumors, only the involved ovary and fallopian tube may be removed. In more advanced disease surgically removing all abdominal metastases enhances the effect of chemotherapy and helps improve survival.
PET/CT imaging has shown variable results in imaging ovarian cancer due to variable uptake of the radiopharmaceutical 2-Deoxy-2-[ 18 ]Ffluoro-D-Glucose (FDG) in normal ovaries and increased uptake in ovarian inflammatory disease. Very small peritoneal metastases are often missed by PET/CT.
However, PET/CT has been found to be useful to guide physicians for surgical debulking, the removal of as much of the cancerous tissue as possible before administering other treatment such as chemotherapy.
In addition, PET/CT is often used in the monitoring of patients after treatment so that the physician can determine if the treatment was effective.
A PET/CT scan can help show where tumor cells are growing, and help your doctor determine the best course of treatment.
Ovarian Cancer Follow-up
After treatment, physicians will schedule routine follow-up visits and, depending on the type of the cancer, may use blood tests to help watch for a possible recurrence. Doctors may also order follow-up imaging tests or surgeries. If the cancer does return, early detection of recurrent disease is important so that additional treatment can begin immediately.
Ovarian cancer does have a biochemical marker, CA-125, and this has been useful in the monitoring of patients after treatment. PET/CT scanning can help the physician in localizing recurrent metastatic disease in patients with elevated serum CA-125 levels but negative CT scans. Recurrence may be diagnosed on the basis of a rising CA-125 level, but PET/CT scanning is useful to help the physician localize and determine the extent of the recurrent disease.
PET/CT imaging helps the physician assess recurrent disease.
Ovarian Cancer PET/CT Utilization
PET/CT is a noninvasive test that physicians utilize to stage for the presence or absence of active tumor, localize the tumor, assess the tumor response to treatment, and detect recurrence in treated lesions.
Ovarian Cancer Indications:
- Identifying primary tumor, except small Stage I cancers.
- Detecting peritoneal metastatic disease, except very small peritoneal implants.
- Guiding surgical debulking for removal of cancerous tissue before chemotherapy.
- Evaluating patients with suspected recurrent disease with rising CA-125 and negative CT scan.
Source: Atlas of Clinical Positron Emission Tomography by Sallie F. Barrington, Michael N. Maisey and Richard R. Wahl. Oxford University Press, Inc. New York, NYSource: Positron Emission Tomography: Basic Science and Clinical Practice. Peter E. Valk, Dale L. Bailey, David W. Townsend, Michael N. Maisey. Springer-Verlag London Limited.