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Abstracts Objectives: To evaluate the effectiveness of two prostate biopsy schemes, by correlating the cancer detection and the biopsy scheme used. Methods: From 2000 to 2005, we studied 700 patients who underwent transrectal ultrasound and prostate biopsy at Sao Paulo Hospital. The patients were divided in two groups. Group A was composed by 408 patients who underwent prostate biopsy where six fragments were taken; and group B was composed by 292 patients who underwent prostate biopsy where 12 fragments were taken. Results: From the total amount of patients, 254 had cancer (36,3%) and 446 did not (63,7%). Among the 408 biopsies with six fragments (Group A), 143 (35%) had cancer and 265 (65%) did not. Out of the 292 biopsies with 12 fragments (Group B), 111 (38%) presented positive results for cancer and 181 (62%) did not. The difference between these two schemes was 3%. This result was not statistically significant (p ⫽ 0,421). The patients with prostate cancer had averages of: 69,6-y for age, 41,4 cm3 for prostate volume, 13,11 ng/ml for PSA and 0,4 ng/ml by gram for PSA density. Conclusions: There was no relation between the cancer diagnosis and the two biopsy schemes studied. 2176 The value of contrast-enhanced US imaging in the reduction of TRUS-guided biopsies and minimization of complications: Impact on prostate cancer detection Zoumpoulis PS, Alexopoulos D, Faitaki S, Theotokas I, Leli D, Pahos K, Plagou A, Echonet: The Ultrasound Network www.echonet.gr, Greece Objectives: To survey the physics and technology of US contrast agents and to demonstrate the procedure of contrast enhanced targeted biopsy of prostatic lesions. Methods: The low sensitivity of B-mode and color Doppler TRUS in prostate cancer detection renders necessary the performance of systematic prostate biopsy with a frequently low yield. Contrastenhanced TRUS improves detectability of malignancy by revealing regions of increased vascularity, which may be targeted selectively to obtain biopsy specimens. In our study contrast-enhanced targeted biopsy was performed to 90 patients after IV administration of the US microbubble contrast agent SonoVue® (Bracco International). Comparison of cancer detection rates for USCA targeted biopsies and conventional systematic biopsies (control group) indicated improved yield with targeted biopsies. Furthermore, the frequency and severity of complications were reduced when the biopsy was performed under contrast enhancement direction. These initial results demonstrate the potential of contrast enhanced TRUS to decrease the number of biopsy cores and improve the sensitivity of prostate cancer diagnosis. Results: Contrast enhancement aids in the detection and accurate sampling of prostate cancer. Conclusions: USCA are the most helpful in detecting prostate cancer lesions that are not easily visible on TRUS allowing for a smaller number of samples and for precision sampling. 2177 Is there a relation between pain and prostate volume during transrectal prostate biopsy? A retrospective linear regression models Yun TJ, Lee HJ, Kim SH, Seoul National University Hospital, Korea Objectives: To determine the relationship between pain and prostate volume during transrectal prostate biopsy. Methods: Between March 2004 and September 2004, total prostate volume, peripheral zone volume and transition zone volume of 71

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patients to prostate biopsies were retrospectively analyzed. And pain was assessed with a Visual Analog Scale, during periprostatic nerve block (VAS 1), during the biopsies procedure (VAS 2) and 20 min after them (VAS 3). Associations between prostate volume and pain during transrectal prostate biopsy were retrospectively evaluated using linear regression models. Results: Total prostate volume was positively associated with VAS 2 (p ⫽ 0.0220) and VAS 3 (p ⫽ 0.0012). Peripheral zone volume was also positively associated with VAS 2 (p ⫽ 0.0231) and VAS 3 (p ⫽ 0.0001). But no significant association could be demonstrated between total prostate volume or peripheral zone volume and VAS 1. And there was not any relation between transition zone volume and VAS values. Conclusions: Higher volume of total prostate or peripheral zone is related to higher level of pain during and after transrectal prostate biopsy. They suggest that additional analgesic strategy is necessary for larger prostate or peripheral zone. 2178 The early clinical experience of mechanical HIFU for benign prostatic hyperplasia Lin XL, Bo HX, Hu GX, Sheng YS, Xi ZG, Feng WX, People’s Hospital, Peiking University, China Objectives: To evaluate the safety and effect of mechanical HIFU (large power, short duration pulse ) for benign prostatic hyperplasia (BPH). Methods: 22 cases of BPH were treated by mechanical HIFU, the I-PSS score peak uroflow and mean uroflow, residual urine and the volume of prostate were measured at 1 week, 1 month, 3 months and 6 months after HIFU. Results: The I-PSS score decreased significantly at 1 week, 1 month and 3 months after HIFU, the effective rate was 90.9%, and the peak uroflow rate and mean uroflow rate increased significantly at 1 week, 1 month and 3 months after treatment, the volume of prostate has no significant change after treatment, but the effective rate was 68.2% at 6 months. Conclusions: Mechanical HIFU for BPH has the advantage of no pain, disuse anesthesia, no skin burns, disuse urinary canal and need not hospitalization and so on, the near curative effect is satisfaction, the efficacy and mechanism and the factors affecting efficacy is unknown and need to be observed and studied. 2179 Contrast-enhanced US for guiding RF ablation of prostates with urethral and neurovascular cooling Liu J-B, Wansaicheong G, Merton D, Sun Y, Goldberg B, Forsberg F, Edmonds P, Needleman L, Halpern E, Thomas Jefferson University Hospital, United States of America; Tan Tock Seng Hospital, Singapore; Shandong Provincial Medical Imaging Research Institute, China Objectives: To investigate the use of contrast-enhanced ultrasound (CEUS) for guiding prostate radiofrequency (RF) ablation in a canine model with and without cooling to protect surrounding structures. Methods: A Radionics RF generator with Cool-TipTM electrode was used to ablate the prostate in 13 dogs. Pulse inversion harmonic imaging (PIHI) with Sonazoid (bolus: 0.04 ml/kg, IV infusion: 0.015 ␮l/kg) was performed using an Elegra scanner with a 6.5EC10 probe. In a control group (n ⫽ 4), no protection was used. In five dogs, urethral protection was provided by a Foley catheter with cold saline infusion (100 ml/min, 0 to16°C). In four dogs, further protection of the neurovascular bundle (NVB) vessels was provided by cold saline (4°C) infusion into the iliac arteries (IA). Results: CEUS allowed monitoring of urethral and NVB blood flow during ablations. Urethral flow was preserved in the seven dogs with