What imaging methods are there for prostate cancer?

Prostate cancer is the most common malignant tumor of the male reproductive system. Its incidence increases with age. There are obvious regional differences in its incidence, with higher incidence in Europe and America. It is reported to be the second leading cause of cancer death in men, second only to lung cancer. However, prostate cancer can be diagnosed early through some specific methods. Let me tell you how to diagnose prostate cancer through imaging examinations.

Several imaging examinations for prostate cancer

1. Computed tomography (CT) examination: CT is a tomography scan that can obtain information about each cross section of human tissue. It has a very limited role in judging prostate cancer itself, but it can judge the invasion of adjacent tissues and organs of the tumor and metastatic lymph node enlargement in the pelvis. Therefore, the purpose of CT examination for prostate cancer patients is mainly to assist clinicians in clinical staging of tumors. (We have repeatedly mentioned the staging of prostate cancer, and there will be a section dedicated to the staging of prostate cancer later)

2. Magnetic resonance imaging (MRI/MRS) scan: MRI examination can show whether the prostate capsule is intact and whether it invades the surrounding tissues and organs of the prostate. MRI can also show the invasion of pelvic lymph nodes and bone metastasis lesions. Therefore, the most important role of nuclear magnetic resonance is also reflected in the staging of tumors. Magnetic resonance spectroscopy (MRS) is based on the differences in the metabolism of citrate, choline and creatinine in prostate cancer tissue and prostate hyperplasia and normal tissue, showing different spectral lines, and has certain value in the diagnosis of prostate cancer. MRI examinations are often unable to make a clear diagnosis when distinguishing prostate cancer from prostatitis with calcification, larger benign prostate hyperplasia, prostate scars, tuberculosis and other lesions. Therefore, imaging examinations such as TRUS, CT, and MRI have limitations in the diagnosis of prostate cancer, and the final diagnosis requires a prostate puncture biopsy to obtain a histological diagnosis.

3. Whole body radionuclide bone scintigraphy (ECT): The most common distant metastasis site of prostate cancer is the bone. ECT can detect bone metastases 3 to 6 months earlier than conventional X-rays. Once the diagnosis of prostate cancer is established, whole body radionuclide bone scintigraphy is recommended (especially in cases with pSA>20ng/ml and Gleason score>7) (Note: the Gleason scoring system will be introduced to you in detail later), which helps to determine the accurate clinical stage of prostate cancer.

Which imaging test is most useful in diagnosing prostate cancer?

Because the prostate is located in the small pelvis, there are many interferences from the surrounding bone artifacts. In addition, the density difference between prostate cancer and normal prostate tissue is small, so the diagnostic value of CT and other examinations is limited. MRI has higher tissue resolution and multi-directional multi-parameter imaging, especially for early tumors confined to the prostate capsule, it has better display and is the preferred imaging examination method for the prostate. MRI manifestations: The signal change of the lesion is obvious in TWl, which is manifested as a low-signal nodule shadow in the surrounding band of higher signal.