Head and neck cancer occurs when certain cells within the head and neck grow in an uncontrolled, abnormal, manner. The majority of head and neck cancers begin in cells lining the mouth and nose, including the lips, tongue, gums, sinuses, naval cavity, pharynx and larynx.
According to the National Cancer Institute, more than 55,500 new cases of head and neck cancer were diagnosed and approximately 12,598 people died from the disease in 2009. Head and neck cancers account for approximately 3 to 5 percent of all cancers in the United States.
Treatment of head and neck cancers includes surgery, radiation therapy and chemotherapy. New developments in molecular imaging technologies are dramatically improving the ways in which head and neck cancer is diagnosed and treated. Research in molecular imaging is also contributing to our understanding of the disease and directing more effective care of patients with head and neck cancer.
What molecular imaging technologies are used for head and neck cancers?
The most commonly used molecular imaging procedure for diagnosing or guiding treatment of head and neck cancer is positron emission tomography (PET) scanning, which is often used in conjunction with computed tomography (CT) scanning, and sentinel node biopsy.
What is PET?
PET involves the use of an imaging device (PET scanner) and a tiny amount of radiotracer that is injected into the patient’s bloodstream. A frequently used PET radiotracer is fluorodeoxyglucose (FDG), which the body treats like the simple sugar glucose. It usually takes between 30 and 60 minutes for the FDG distribution throughout the body to become fixed. A CT is also obtained on the same machine so the FDG and CT scans can be fused together and compared.
How is PET used for head and neck cancer?
- diagnose and stage: by determining the location of the cancer and where the cancer has spread in the body; patients with head and neck cancer are scanned from the top of the head to the thighs.
- plan treatment: be determining a site that is appropriate for biopsy and in research studies, by helping to select the best therapy based on the unique biology of the cancer and of the patient.
- evaluate: how the cancer responds to treatment and distinguish changes due to radiation therapy from a cancer recurrence, which can be difficult to determine with CT alone
- manage ongoing care: through early detection of cancer recurrences.
What are the advantages of PET for people with head and neck cancers?
- PET scanning is the most significant advance in the staging of head and neck cancers in recent years
- PET is a powerful tool for diagnosing and determining the stage of many types of head and neck cancers
- PET and PET-CT scans prompt changes in the treatment of more than one-third of patients registered in the National Oncologic PET Registry (NOPR)
- The National Comprehensive Cancer Network (NCCN) has incorporated PET-CT into the practice guidelines for most malignancies
- By detecting whether lesions are benign or malignant, PET scans may eliminate the need for surgical biopsy or, if biopsy is necessary, identify the optimal biopsy location
- PET scans help physicians choose the most appropriate treatment plan and assess whether chemotherapy or other treatments are working as intended
- PET scans are currently the most effective means of detecting a recurrence of cancer.
What is the future of molecular imaging and head and neck cancers?
In addition to increasing our understanding of the underlying causes of disease, molecular imaging is improving the way disease is detected and treated. Molecular imaging technologies are also playing an important role in the development of:
- screening tools, by providing a non-invasive and highly accurate way to assess at-risk populations
- new and more effective drugs, by helping researchers quickly understand and assess new drug therapies
- personalized medicine, in which medical treatment is based on a patient’s unique genetic profile
In the future, molecular imaging will include an increased use of:
- fusion or hybrid imaging, in which two imaging technologies are combined to produce one image
- optical imaging
- new probes for imaging critical cancer processes
- reporter-probe pairs that will facilitate molecular-genetic imaging
- PET-CT to help administer more targeted radiation treatments