Role of multiparametric MRI in detection of prostatic lesions; of evaluation contrast enhanced MRI, diffusion weighted imaging and MR spectroscopy in malignant and benign prostatic lesions

Abstract

INTRODUCTIONProstate cancer is the most common cancer detected in men in the United States. Approximately 230,000 American men were diagnosed with prostate cancer in 2005.1 Prostate cancer is the second leading cause of cancer death for men.Despite the efficiency of clinical staging, it remains imperfect for precise local cancer staging and intra ABSTRACT Background: Prostate cancer is the most commonly diagnosed cancer in males and one of the leading causes of cancer-related death in men. Pretreatment assessment of prostate cancer is divided into detection, localization, and staging; accurate assessment is a prerequisite for optimal clinical management and therapy selection. The purpose of the study is to determine the diagnostic accuracy of multiparametric MRI for prostatic cancer detection using T2 weighted MR imaging, diffusion weighted imaging (DWI) and contrast enhanced MRI. To determine the use of MR spectroscopy in prostatic lesions. Methods: It is a prospective single institutional study done on 29 patients with prostate lesions and elevated PSA level. Axial, coronal and sagittal images were obtained using T1WI, T2WI and STIR sequences. Advanced sequences like Diffusion weighted images, Spectroscopy and post gadolinium T1WI were taken after the basic MRI images. Results: Study was done in 29 patients, age was ranging between 51years to 90 years, mean age is 70.7 years. On multiparametric MRI findings 45% were detected malignant lesions and 55% patients detected benign lesions. On biopsy correlation 42% of these cases turned out to be malignant and 58% as benign lesions. Detection of malignancy by T2WI imaging alone given sensitivity of 80.1% and specificity of 85.4%.By DWI alone sensitivity was 85.7% and specificity was 89.4%,on MRS sensitivity is 90.6% and specificity was 91.1%. Combined (MRI+DWI+MRS) gave sensitivity of 92.3% and specificity of 94.4% for detection of malignant prostatic lesion. Positive predictive value is 90% and negative predictive value was 88%. Conclusions: The best characterization of prostatic cancer in individual patients will most likely result from a multiparametric exam. Recent advances include additional functional and physiologic MR imaging techniques (diffusion weighted imaging, MR spectroscopy, and perfusion imaging), which allow extension of the obtainable information beyond anatomic assessment. Multiparametric MR imaging provides the highest accuracy in diagnosis and staging of prostate cancer.