Prostate Cancer - Metastatic Prostate Carcinoma

Clinical History

A 69 year old man was diagnosed in 2004 with prostate carcinoma and treated with transurethral resection followed by chemotherapy and hormone therapy.

An 18F Sodium Fluoride bone scan performed in March 2006, during his initial work-up, showed skeletal metastases in the right ischium and right 6th and left 5th rib anteriorly.

The patient presented with an increasing PSA level. It had increased from 4.6 on September 5, 2006 to 21 on October 3, 2006. An FDG PET•CT study was ordered for restaging of suspected metastatic disease.

Imaging Findings*





The FDG PET•CT study showed a hypermetabolic 30 mm left inguinal mass adjacent to the medial margin of the left common femoral artery. This metastatic node had increased in size from 20 mm (noted in a previous CT scan performed in September 2005). There was also a hypermetabolic 10 mm subcutaneous metastatic nodule lateral to and at the level of the right greater trochanter. This nodule also showed significant increase in size as compared to a previous CT scan (Fig. 1). There was also a hypermetabolic right hilar node with an SUV of 4.5. In view of hilar nodal metastasis being unusual in prostate cancer, this right hilar lesion is probably related to inflammatory or granulomatous origin. No other pulmonary lesion or pleural effusion was visualized (Fig. 2)

Thoracic and abdominopelvic CT studies were also performed and corroborated the PET•CTfindings.

Discussion

Metastatic disease was suspected based on the increase in PSA. The restaging FDG PET•CTstudy confirmed the clinical suspicion of fresh metastatic disease. The atypical hilar nodal FDG uptake was suggestive of granulomatous disease. However the inguinal node with increasing size and high FDG uptake clearly suggested metastases.

Data courtesy of Mike Medeiros, Chief Technologist, Western Washington Oncology, Lacey, WA

* Any of the protocols presented herein are for informational purposes and are not meant to substitute for clinician judgment in how best to use any medical devices. It is the clinician that makes all diagnostic determinations based upon education, learning and experience.