Cross-sectional imaging with magnetic resonance im

Cross-sectional imaging with magnetic resonance imaging and transrectal ultrasound

MRI with a high-tesla magnet (1.5–3 /uni00A0 T) is the most accurate method of staging local disease. mpMRI is used preoperatively to assess pelvic lymph nodes as well as local stage, although the sensitivity of mpMRI to detect small areas of capsular spread is limited, even in the best hands. As well as preoperative staging, mpMRI plays an important role in active surveillance and localisation of recurrent prostate cancer after surgery . Low-grade tumours are frequently not seen on MRI and are often clinically insignificant. TRUS scanning can also be used to stage prostate cancer. Locally extensive disease (T2) can be diagnosed with increased sensitivity by TRUS ( Figure 84.15 ) compared with rectal examination, but many tumours will still be missed. This prob - lem remains a real one in screening for early prostate cancer; in comparison with breast cancer, with mammography detecting 70–80% of tumours, TRUS plus rectal examination and mea - surement of PSA will detect only 30–50% of cancers that are known to be present on autopsy studies (although it may detect the larger, more significant cancers).