PURPOSE To explore the impact of MRI-ultrasound (MRI-US) fusion prostate biopsy on prediction of final surgical pathology. MATERIALS AND METHODS 54 consecutive men undergoing radical prostatectomy at UCLA after Artemis fusion biopsy (Eigen, Grass Valley, CA) were included in this prospective IRB-approved pilot study. Using MRI-US fusion, tissue was obtained from a 12-point systematic grid (mapping biopsy, MBx) and from regions of interest detected by multi-parametric MRI (targeted biopsy, TBx). A single radiologist read all MRIs, and a single pathologist independently re-reviewed all biopsy and whole-mount pathology, blinded to prior interpretation and matched specimen. Gleason score (GS) concordance between biopsy and prostatectomy was the primary endpoint. RESULTS Mean age was 62 years, with median PSA 6.2 ng/ml. Final GS at prostatectomy was 6 (13%), 7 (70%), and 8–9 (17%). A tertiary pattern was detected in 17 (31%) men. 32/45 (71%) high-suspicion (image grade 4–5) MRI targets contained prostate cancer (CaP). The per-core cancer detection rate was 20% by MBx and 42% by TBx. The highest Gleason pattern at prostatectomy was detected by MBx in 54%, TBx in 54%, and the combination in 81% of cases. 17% were upgraded from fusion biopsy to final pathology; one case (2%) was downgraded. The combination of TBx and MBx was needed to obtain the best predictive accuracy. CONCLUSIONS In this pilot study, MR-US fusion biopsy allowed for prediction of final prostate pathology with greater accuracy than that reported previously using conventional methods (81% versus 40–65%). If confirmed, these results would have important clinical implications.

No abstract

Tumor histopathology is an important method to understand the mechanism of action of anti‐neoplastic therapies and immunotherapeutics in animal models. An experimental metastasis model was established with the MDA‐MB‐231 human breast adenocarcinoma cell line in SCID beige mice. Compared to subcutaneous and orthotopic models, this model allows evaluation of multiple lesions at earlier time points. Mice were injected i.v. with MDA‐MB‐231 cells and sacrificed either 14 or 21 days post tumor cell injection. Lungs were processed for histology and stained with H&E. Multiple focal lesions were observed and these lesions had a random distribution in the lung and were variable in size. The lesions increased in size and number over time. These observations were confirmed by a rank order analysis on disease severity, and morphometry on size of the lesions. Morphometry also revealed a significant increase in proliferating cells within lung lesions at Day 21 compared to Day 14. Numerous infiltrating macrophages could also be identified within the lesions. No evidence of angiogenesis within the lesions was observed in this time course. It is hypothesized that the lesions studied have not yet crossed the angiogenic switch and therefore no new blood vessel formation was observed. Lesions can be further characterized by additional histologic methods.