Contrast specific imaging in the detection and localization of prostate cancer

Prostate cancer (PCa) is the most common cancer in elderly men and is one of the most important causes of death from cancer in men. The diagnosis of PCa is based on a combination of digital rectal examination, PSA and transrectal ultrasound (TRUS). However, this combination does not reach the accuracy of detection and localization necessary for proper decisions on treatment methods. Therefore, biopsies are performed in all cases for which the suspicion of PCa is raised. Even with biopsies, staging and grading of PCa is far from optimal. More accurate imaging is necessary to improve the biopsy sampling, the goals being to replace systematic biopsies by a targeted approach and to improve staging and grading of PCa. Ultrasound imaging of the prostate remains the first choice of imaging to visualize the prostate, however, gray-scale ultrasound imaging has an accuracy of about 50-60% for the detection of PCa and TRUS used for local staging has an even lower accuracy. The development of PCa is associated with changes in the metabolism of tumor cells, and therefore with changes in the blood perfusion of the involved tissue. This paper focuses on contrast specific imaging techniques to visualize these changes in blood perfusion. Techniques such as color and power Doppler imaging, and contrast enhanced imaging techniques using color and power Doppler, harmonic imaging and intermittent imaging are discusse

Ultrasound imaging and contrast agents: a safe alternative to MRI?

Microbubble contrast media are used to enhance ultrasound images. Because ultrasound is a real-time investigation, contrast-enhanced ultrasound offers possibilities for perfusion imaging. This review is conducted to evaluate the safety of contrast-enhanced ultrasound and its possible role in medical imaging. The safety of diagnostic ultrasound is still an important field of research. The wanted and unwanted effects of ultrasound and microbubble contrast media as well as the effects of ultrasound on these microbubbles are described. Furthermore, some of the possible applications and indications of contrast-enhanced ultrasound will be discussed. The shared advantages of MRI and ultrasound are the use of non-ionizing radiation and non-nephrotoxic contrast media. From this review it can be concluded that, for certain indications, contrast enhanced ultrasound could be a safe alternative to MRI and a valuable addition to medical imagin

Ultrasonography of renal masses using contrast pulse sequence imaging: a pilot study

BACKGROUND AND PURPOSE: The use of contrast-enhanced ultrasonography for imaging of renal masses was first described in 1994. Since then, many new techniques for visualization of the effect of microbubble contrast agents have been developed. In this pilot study, a small number of patients was investigated with contrast pulse sequence imaging (CPS), and the characteristics of this perfusion imaging technique were evaluated subjectively and judged against the clinical diagnosis and histology findings when available. The purpose of this pilot study was to describe CPS imaging in several cases. PATIENTS AND METHODS: Eighteen patients with 20 previously identified renal masses were examined with CPS. Perfusion imaging was compared with clinical diagnosis and with histologic findings when available. RESULTS: Nineteen masses were visible. Various enhancement patterns could be observed, and interpretations of CPS characteristics are described. In carcinomas, inhomogeneous enhancement patterns were observed, and areas without enhancement inside the inhomogeneous lesions corresponded to necrotic areas in histologic specimens. All simple cysts and complex benign cysts showed absence of enhancement inside or in the wall of the lesion and a regular shape. CONCLUSION: To our knowledge, this is the first study in which the characteristics of CPS imaging of renal masses have been related to clinical diagnoses and histologic features. From the results of this pilot project, we conclude that CPS is a promising technique to determine perfusion patterns in the kidne

Nephron-sparing surgery and percutaneous biopsies in renal-cell carcinoma: a global impression among endourologists

BACKGROUND AND PURPOSE: On the one hand, nephron-sparing surgery (NSS) in small renal tumors is a safe and effective alternative to radical nephrectomy. On the other hand, the role of preoperative percutaneous needle biopsies (PNB) remains controversial. The purpose of this study was to evaluate the global current use of NSS in the treatment of renal-cell carcinoma (RCC) and the use of PNB among endourologists. MATERIALS AND METHODS: One thousand questionnaires were distributed during the 23rd World Congress of Endourology and SWL. Six questions regarding NSS and two questions regarding PNB were presented. Two hundred twenty-two questionnaires were returned. RESULTS: Of the respondents, 86.6% perform NSS for small renal tumors, whereas 13.4% perform only radical nephrectomies; 7.5% will consider NSS only in patients with a solitary kidney, and 0.5% will never consider NSS. The techniques for NSS, in descending order of preference, are partial nephrectomy, enucleation, cryoablation, radiofrequency ablation, and high-intensity focused ultrasound. The mean and maximum diameter of the tumor in patients with a normal contralateral kidney for which the urologists perform NSS is 4.0 cm. For a centrally located tumor, NSS is an option for 27.2% of the respondents. Regarding PNB in patients with suspicion of RCC, 55.9% of respondents never obtain renal biopsies in the preoperative assessment and 41.8% obtain them only in rare cases. The majority (90%) prefer histologic over cytologic biopsies. CONCLUSIONS: Nephron-sparing surgery is evolving to a global worldwide standard treatment for small renal tumors. Percutaneous needle biopsy remains a highly debated procedur

Optimizing prostate cancer detection: 8 versus 12-core biopsy protocol

PURPOSE: We compared prostate cancer detection rates achieved using an 8 and 12-core biopsy protocol in a clinical population to determine the significance of additional transition zone sampling on repeat biopsy. MATERIALS AND METHODS: Between September 2004 and September 2007, 269 eligible patients with a clinical suspicion of prostate cancer referred to our department were randomized to an 8-core lateral (group 1) or a 12-core lateral and parasagittal (group 2) transrectal ultrasound guided prostate biopsy protocol. Study inclusion criteria were age dependent increased serum prostate specific antigen (1.25 ng/ml or greater at ages less than 50 years, 1.75 or greater at ages 50 to less than 60 years, 2.25 or greater at ages 60 to less than 70 years and 3.25 or greater at ages 70 years or greater), positive digital rectal examination and/or suspicious transrectal ultrasound. After negative first round biopsy patients underwent 12-core biopsy, including 4 transition zone cores. RESULTS: Nine patients were excluded from analysis because of protocol violation or they did not complete the whole biopsy procedure due to discomfort. The cancer detection rate in groups 1 and 2 did not differ significantly (34.1% or 45 of 132 patients and 38.3% or 49 of 128, respectively, p = 0.48). Detected cancer median Gleason scores were similar in the groups. Of 109 patients who underwent repeat biopsy prostate cancer was detected in 20 (14.4%), of whom 9 had positive cores from the transition zone and 6 had positive biopsies only from the transition zone. CONCLUSIONS: There are no statistically significant differences in the prostate cancer detection rate between 8 and 12-core prostate biopsy protocols. Transition zone biopsies contribute to prostate cancer detection in a repeat biopsy protoco