Faculty Bibliography

OBJECTIVES: Multi-parametric MRI is emerging as a promising method for prostate cancer diagnosis. prognosis and treatment planning. However, the localization of in-vivo detected lesions and pathologic sites of cancer remains a significant challenge. To overcome this limitation we have developed and tested a system for co-registration of in-vivo MRI, ex-vivo MRI and histology. MATERIALS AND METHODS: Three men diagnosed with localized prostate cancer (ages 54-72, PSA levels 5.1-7.7 ng/ml) were prospectively enrolled in this study. All patients underwent 3T multi-parametric MRI that included T2W, DCE-MRI, and DWI prior to robotic-assisted prostatectomy. Ex-vivo multi-parametric MRI was performed on fresh prostate specimen. Excised prostates were then sliced at regular intervals and photographed both before and after fixation. Slices were perpendicular to the main axis of the posterior capsule, i.e., along the direction of the rectal wall. Guided by the location of the urethra, 2D digital images were assembled into 3D models. Cancer foci, extra-capsular extensions and zonal margins were delineated by the pathologist and included in 3D histology data. A locally-developed software was applied to register in-vivo, ex-vivo and histology using an over-determined set of anatomical landmarks placed in anterior fibro-muscular stroma, central. transition and peripheral zones. The mean root square distance across corresponding control points was used to assess co-registration error. RESULTS: Two specimens were pT3a and one pT2b (negative margin) at pathology. The software successfully fused in-vivo MRI. ex-vivo MRI fresh specimen and histology using appropriate (rigid and affine) transformation models with mean square error of 1.59 mm. Coregistration accuracy was confirmed by multi-modality viewing using operator-guided variable transparency. CONCLUSION: The method enables successful co-registration of pre-operative MRI, ex-vivo MRI and pathology and it provides initial evidence of feasibility of MRI-guided surgical planning.

Epidemiologic and experimental data suggest that soy consumption may prevent prostate cancer and be beneficial for men with prostate cancer. Soy intake and risk of prostate cancer are inversely correlated; soy isoflavones inhibit growth of prostate cancer cells and reduce prostate carcinogenesis in animal models. We tested the hypothesis that soy consumption reduces biochemical recurrence after radical prostatectomy in a randomized controlled clinical trial with a soy protein supplement versus a casein-based placebo in men at increased risk for PSA failure in the first 2 years after radical prostatectomy. PSA was tested at 2-month intervals in year 1 and every 3 months in year 2. Eligibility criteria were: Gleason sum of >8, extra-capsular extension, seminal vesicle invasion, positive surgical margins, positive lymph nodes, and/or a preoperative PSA of >20 ng/ml. Biochemical recurrence was defined a priori as reaching a PSA value of alpha0.07 ng/ml, confirmed twice. A two-year PSA failure rate in eligible subjects of approximately 30% was expected, based on data from NYU and previous literature. With a planned sample size of 128 evaluable subjects per arm, the study had 80% power to detect a 50% reduction in PSA failure rate at a 2-sided significance level of 0.05. The soy protein isolate and placebo (generously provided by Solae LCC, St Louis, MO) were identical in composition, except for the protein source (19.2-19.8 g protein/day); the soy product provided daily 23.5 mg genistein and 40.9 mg total isoflavones (aglycone equivalents); the placebo was devoid of any soy-specific constituents. Accrual did not reach the intended level and 172 subjects were randomized and enrolled, of whom 142 were evaluable (completed two years on study or developed confirmed recurrence within two years). Soy protein consumption did not alter recurrence rate or time-to-recurrence (TTR). Of the 74 evaluable subjects in the soy arm 22 (30%) recurred as did 22 (32%) of the 68 subjects in the placebo arm recurred. The!