While multiparametric MRI and color Doppler ultrasound are excellent tools for monitoring disease inside the prostate, scanning the rest of the body for cancer that may have spread to the lymph nodes or bones is also critical. Body scans are necessary for every Stage of Blue except Sky. Traditionally, doctors have relied on CT scans and bone scans. However, their accuracy is disappointing. Undetected spread is the most common reason for cancer recurrence after the initial treatment. Positron emission tomography (PET) scans provide three-dimensional images of the whole body.
After lymph nodes, bone is the second most common site of metastatic spread. Standard bone scans use a radio-tracer called Technetium-99, which is unfortunately not very specific. Other changes in the bone, such as arthritis or benign lesions, can be mistaken for cancer metastasis. A PET scan called NaF18 (radioactive sodium fluoride) provides superior specificity and sensitivity when compared with Technetium-99.
Axumin, Galium-68 PSMA, and Choline PET scanning for prostate cancer are a giant leap forward over older scanning techniques. Preliminary studies with Galium-68 PSMA provide excellent images, though this technology is still investigational. Axumin detects increased amino acid metabolism in the cancer cells. Axumin is now FDA approved and has recently become commercially available.