Hussein Aoun, MD, a radiologist at Barbara Ann Karmanos Cancer Institute, discusses the imaging modalities that are currently being used in prostate cancer and how they compare with conventional imaging modalities.

MRI or ultrasound can be used for local staging in prostate cancer, says Aoun. However, ultrasound is used primarily to guide a biopsy, whereas MRI is more commonly used for local staging and identifying suspicious lesions. Additionally, MRI can have a significant impact on the patient's care, says Aoun.

In terms of metastatic disease, the PET scan has taken on a greater role in the field and new tracers have helped identify early recurrences. For example, with agents such as 18F-fluciclovine (Axumin), radiologists can identify lesions that would not have been seen with a CT scan or conventional bone scan earlier on.

Prior to the use of next-generation imaging modalities, ultrasound was used for local imaging and staging, adds Aoun. The sensitivity and specificity of ultrasound was relatively poor in detecting prostate cancer, unless patients had a visible nodule. MRI has a very high resolution, which allows for the identification of clinically significant lesions and staging of local disease to see if the patient has extraprostatic extension, concludes Aoun.