Clinical Implications of Prostate Cancer
Prostatic carcinoma is a common oncological problem, and even today many issues upon diagnosis, staging, and treatment selection remain controversial. Imaging modalities play a crucial role in the diagnosis, in staging, and in the follow-up period of treatment in patients with PCa. Overdiagnosis and overtreatment is a major problem, and until the biological characteristics of the aggressive tumors that need treatment are identified, screening cannot be advocated. New imaging technologies (MRI, PET scans) are being tested, and in some cases they offer extra information to the clinicians. The goal of every urologist is to intervene when he believes that he will improve the survival of his patients without hampering the quality of their lives.
KeywordsProstate cancer Imaging modalities Transrectal ultrasonography Computerized tomography Magnetic resonance imaging Positron emission tomography
91.1 Diagnosis Staging
Transurethral ultrasound (TRUS)-guided biopsies are the best method to diagnose prostatic carcinoma, and a minimum of 8–12 biopsy cores are recommended depending on the size of the gland. TRUS offers information for local staging (T staging) as well, but due to its low sensitivity, MRI images can offer valuable information. The evaluation of pelvic lymph nodes (N staging) is done with CT scans, but small metastases cannot be identified with preoperative imaging technology, and therefore lymph node surgical dissection is still needed in cases where the Gleason score is >6 or when the PSA value is >20 ng/ml. Skeletal metastases (M staging) are best evaluated with bone scans. In ambiguous cases where dilemmas arise, C-choline-, F-flouride-PET/CT, and whole body MRI have been offered as an alternative option, but these modalities should not be used routinely in everyday practice [1, 2].
91.2 Follow-Up Strategies
TRUS and biopsy have been used to detect local recurrence, but it is recommended only if it will change the treatment decision and if a palpable lesion is present. Metastatic sites can be detected with CT or MRI scans and with bone scans. These modalities should not be used routinely in patients with stable low PSA values and will offer information when symptoms become present or when the PSA value exceeds the level of 20 ng/ml. For the identification of local recurrence after radical prostatectomy, endorectal MRI has been used, but it is not recommended in every case. PET/CT has been examined in patients with biochemical relapse after definitive treatment (radical prostatectomy and local radiation), and it has been shown that metastases can be identified. The capacity of this modality to identify metastatic sites is influenced by the PSA level, PSA velocity, and PSA doubling time. With PSA values <1 ng/ml, the assistance of PET/CT is questioned [1, 2].