Is Magnetic Resonance Imaging Necessary in the Staging of Prostate Cancer?

Abstract

Objective: To evaluate the necessity of using magnetic resonance imaging (MRI) in the staging of patients with clinically localized prostate cancer. Methods: Sixty-one patients with prostate cancer were evaluated with MRI for preoperative staging with a conventional body-coil (Siemens Magnetom, 1.0 Tesla superconducting system). Twenty-nine patients underwent radical prostatectomy for presumed clinically localized disease. Of those, 17 were staged both with MRI and computerized tomography (CT). The remaining patients were staged with CT alone. MRI and CT findings, and the final pathologic staging of patients are reviewed. Results: On pathological examination of the surgical specimens, the tumor was found to extend beyond the prostate in 7 patients (41%). Among the 17 patients who were operated, extraprostatic extension (EPE) was detected accurately in 3 patients with MRI (sensitivity 20%, specificity 92%, accuracy 70.5%). No metastatic lymph nodes were detected on the basis of MRI (sensitivity 0%, specificity 93%, accuracy 88.2%). In 1 patient EPE was correctly identified by CT (sensitivity 14%, specificity 100%, accuracy 64.7%). Conclusion: Neither MRI with conventional body-coild nor CT are sufficient to indicate local extension of disease in clinically localized prostate cancer.

Combined Endorectal and Phased-Array MRI in the Prediction of Pelvic Lymph Node Metastasis in Prostate Cancer

“…MRI has also shown high specificity for LNM detection; however, the low sensitivity of MRI (0-69%) in detecting LNMs has been an obstacle to its widespread use. Table 1 is a summary of the results of the major studies on the use of MRI for prostate cancer LNM staging that have used surgical pathology as the standard of reference [6,12].…”

“…The risk of dying of prostate cancer is 17% ± 6% at 10 years for patients with negative nodes compared with 57% ± 11% for patients with positive nodes [4]. Accurate diagnosis of lymph node metastasis (LNM) is essential in treatment selection and planning.Since the late 1980s, studies have consistently shown that MRI has limited value in the assessment of LNM in patients with prostate cancer [6][7][8][9][10][11][12][13][14] (Table 1). Although MRI provides images with excellent anatomic detail for the evaluation of locoregional disease and has high specificity for LNM, the sensitivity of MRI for the detection of LNM is relatively low [15][16][17].…”

Biexponential characterization of prostate tissue water diffusion decay curves over an extended b-factor range

“…According to the American Cancer Society (1) over 230,000 new prostate cancer cases will be diagnosed with some 30,000 deaths estimated in 2004, making prostate cancer the second leading cause of cancer death in men and making early prostate cancer detection and treatment an important health care goal. Excellent anatomical imaging of the prostate is now available from both T1-and T2-weighted scans using endorectal coils in conjunction with multiple receiver coil elements (2)(3)(4)(5)(6)(7)(8)(9)(10). Though such imaging sequences are considered sensitive for prostate cancer detection, they lack specificity and are generally used for staging purposes.…”

Imaging of Prostate Cancer

“…For the assessment of lymph node metastases, MR imaging, like CT, has low sensitivity (0%-69%) [47,[56][57][58][59][60][61]. The low sensitivity of MR imaging and CT is mainly due to the inability of cross-sectional imaging to detect metastases in normal-sized nodes.…”