Urologic cancer. Methods of early detection and future developments
Technologic advances in diagnostic imaging have significantly improved the detection and staging accuracy of urologic cancer. Intravenous urography (IVU) is not sensitive for the detection of renal lesions, and a normal IVU does not exclude the presence of renal cancer. At this time, computed tomography (CT) is the method of choice for the detection of renal tumors. Ultrasound (US) can be used for the differentiation of cystic from solid lesions, but CT is more accurate. Magnetic resonance (MR) imaging presently is inferior to CT for the detection of renal lesions. However, in the staging of known renal carcinoma, MR surpasses CT in the staging of large lesions or lesions of stage III and IV disease. In the detection of bladder tumors, cystoscopy and biopsy remain the most accurate diagnostic method. CT and MR imaging are indicated for the staging of bladder neoplasms. Transurethral US shows promise, but is still under investigation. At present, the combination of physical examination, transrectal US, and when needed, US-guided biopsy, are the optimal screening approaches for the detection of prostatic carcinoma. For the staging of diagnosed prostatic carcinoma, MR is superior to CT, but neither is accurate in assessing lymph node involvement. As compared with transrectal US, MRI is superior for the evaluation of extension to the bladder base and seminal vesicles. It is hoped that in the near future, localized tissue MR spectroscopy will be used clinically and will improve the specificity of diagnosis of prostatic carcinoma.