Ori Preis MD, Presenter: Nothing to Disclose

Alan Fischman MD, Abstract Co-Author: Nothing to Disclose

Hugh D. Curtin MD, Abstract Co-Author: Nothing to Disclose

Suzanne L. Aquino MD, Abstract Co-Author: Nothing to Disclose

To evaluate the necessity of abdominal/pelvic PET/CT in restaging of patients with head/neck and thyroid malignancies.

The institutional review board approved this study. Informed consent was waived. A retrospective review of 3946 consecutive whole-body PET/CT examinations between 3/1/05 and 3/1/07 was performed to identify patients imaged for reevaluation of primary head/neck or thyroid malignancies after therapy. Patients with coexisting second primary malignancies were excluded. All patients received a low dose attenuation correction CT and emission PET scan, followed by whole-body contrast enhanced diagnostic CT scan in the same image setting. Clinical stage prior to PET/CT was reviewed in the medical records. PET/CT scans were analyzed for the presence of metastatic disease in the neck, chest, abdomen and pelvis.

72 patients with thyroid malignancy (51 females, 21 males, age 16-85 years) and 70 patients with head/neck malignancies (21 females, 49 males, ages 19-92 years) were included. Patients received 1-4 restaging scans, for a total of 216 studies (113 head/neck, 103 thyroid). Amongst those with thyroid cancer, 56 patients had known nodal metastases in the neck and 24 had known chest metastases prior to PET/CT. Additional abdominal metastases were identified by PET/CT in 3 patients, all with known thoracic metastases. For head/neck cancer patients, 51 patients had known metastatic neck nodes and 7 had known chest metastases prior to PET/CT. Additional abdominal metastases were diagnosed by PET/CT in 5 patients, 3 with known chest metastases. In the two patients without prior evidence of chest metastases, a clinical suspicion for extrathoracic metastases existed prior to PET/CT. Both patients had metastases in the upper abdomen.

The clinical utility of PET/CT of the lower abdomen and pelvis is limited in head/neck or thyroid cancer patients who lack thoracic metastatic disease.

In patients without known thoracic metastases, thyroid and head/neck malignancies may be sufficiently evaluated with a PET-CT scan from skull base to kidneys, as opposed to whole body PET-CT.

Preis, O, Fischman, A, Curtin, H, Aquino, S, PET/CT Examination of the Neck and Chest Is Sufficient for Restaging Evaluation of Patients with Head/Neck and Thyroid Cancer.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5006250.html