248 ACCURACY OF MULTIPARAMETRIC MAGNETIC RESONANCE PROSTATE IMAGING (MP-MRI) IN CONFIRMING ELIGIBILITY FOR ACTIVE SURVEILLANCE (AS) FOR MEN WITH PROSTATE CANCER (PCA)

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THE JOURNAL OF UROLOGY姞

247 SPATIAL DISTRIBUTION OF POSITIVE CORES DECREASES MISCLASSIFICATION RATES OF PATIENTS WITH LOW RISK PROSTATE CANCER CANDIDATE FOR ACTIVE SURVEILLANCE Firas Abdollah, Ettore Di Trapani, Fabio Castiglione, Niccolo` Maria Passoni, Umberto Capitanio, Andrea Gallina, Manuela Tutolo, Marco Bianchi, Elena Farina, Giorgio Gandaglia, Luca Villa, Nazareno Suardi, Milan, Italy; Vincenzo Mirone, Naples, Italy; Andrea Salonia, Francesco Montorsi*, Alberto Briganti, Milan, Italy INTRODUCTION AND OBJECTIVES: A non negligible proportion of prostate cancer (PCa) patients who fulfill the current active surveillance (AS) criteria harbor unfavorable tumor characteristics at radical prostatectomy (RP). Although several criteria proposed for AS have included detailed biopsy parameters, none of them has considered the pattern of intra-prostatic distribution of positive cores taken at initial biopsy. We tested the hypothesis that positive cores spatial distribution at biopsy is a predictor of unfavorable PCa characteristics at RP in AS candidates METHODS: We examined the data of 524 patients treated with RP, between 2000 and 2012. All men fulfilled at least one of four commonly used AS criteria (namely, JH, PRIAS, MSKCC, UCSF). Univariable and multivariable (MVA)regression models tested the relationship between positive cores spatial distribution, defined as either the number of positive zones at biopsy (PBxZ; namely, right apex, right margin, right base, left base, left margin, left apex) or tumor laterality at biopsy and two endpoints: 1) unfavorable PCa at RP (Gleason score ⱖ4⫹3, and/or pT3 disease), and 2) clinically significant PCa (tumor volume ⱖ2.5 cc, as recently suggested). RESULTS: Overall, unfavorable and clinically significant PCa rates were 8.4% and 25%, respectively. In patients with 1 PBxZ (n⫽393;75%), the rates of pathologically unfavorable and clinically significant tumor was 6.9 (27/393) and 23.1% (91/393), respectively vs. 13% (17/131) and 30.5% (40/131) respectively in men with more than 1 PBxZ (all p ⱕ0.04). Similarly, the rates of unfavorable and clinically significant tumors in men with bilateral tumor at biopsy were 17.7 (14/62) and 33.9% (21/62) vs. 7.1 (33/462) and 23.8% (110/462) in men with unilateral tumor at biopsy. (all p ⱕ0.04). These results were confirmed at multivariable analyses, where patients with ⬎1 PBxZ or bilateral tumor at biopsy had a 3.2-fold and 1.7-2.3 fold higher risk of harboring pathologically unfavorable and clinically significant tumor, respectively, after accounting for age, PSA, prostate volume, clinical stage, number of positive cores, and number of total cores (all p ⱕ0.04). CONCLUSIONS: Positive cores spatial distribution at biopsy should be considered in the clinical decision making process for the selection of patients candidate to AS. The addition of spatial core distribution might help in the identification of patients at a higher risk of progression, thus reducing the rate of inappropriate surveillance of more aggressive tumors.

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tial to detect the presence and volume of PCa. It was the goal of our study to characterize the performance of MP-MRI in confirming AS candidacy. METHODS: We reviewed all men who underwent 3.0T MP-MRI with subsequent MRI/US fusion guided prostate biopsy between 2007uˆ2012 and selected patients who met the Johns Hopkins AS criteria at entry based on their initial biopsy. Multiple characteristics seen on MP-MRI were measured including number of lesions, dominant lesion diameter and volume, total lesion volume (sum of the individual lesion volumes), prostate volume, and “lesion density” (calculated as total lesion volume divided by whole prostate volume). Lesions were assigned a low, moderate, or high suspicion for cancer by the radiologist. AS criteria was then reapplied based on the confirmatory biopsy data, and accuracy of MP-MRI in predicting AS candidacy was assessed. Logistic regression modeling and chi-square statistics were used to assess associations between MP-MRI and biopsy results. RESULTS: Eighty-six patients qualified for AS with a mean age of 60.4 years and mean PSA of 4.94. Of these, 25 patients (34%) were reclassified as no longer fulfilling AS criteria based on their confirmatory prostate biopsy results. Upon univariate analysis, number of lesions (p ⫽ 0.03) and MP-MRI based lesion suspicion for cancer (p ⫽ 0.04) were significantly associated with confirmatory biopsy negating AS candidacy. Lesion density approached significance (p ⫽ 0.051). These three factors were combined to create a nomogram with good accuracy (AUC 0.7). CONCLUSIONS: As urologists counsel patients with newly diagnosed PCa, MP-MRI may contribute to the decision-making process when considering AS. Number of lesions, lesion suspicion, and lesion density were associated with confirmatory biopsy outcome. A nomogram using these three factors has promising predictive accuracy for which future validation is necessary.

Source of Funding: None

Source of Funding: None

248 ACCURACY OF MULTIPARAMETRIC MAGNETIC RESONANCE PROSTATE IMAGING (MP-MRI) IN CONFIRMING ELIGIBILITY FOR ACTIVE SURVEILLANCE (AS) FOR MEN WITH PROSTATE CANCER (PCA) Lambros Stamatakis*, M. Minhaj Siddiqui, Jennifer Logan, Jeffrey Nix, Soroush Rais-Bahrami, Annerleim Walton-Diaz, Anthony Hoang, Srinivas Vourganti, Hong Truong, Baris Turkbey, Peter Choyke, Bradford Wood, Peter Pinto, Bethesda, MD INTRODUCTION AND OBJECTIVES: While AS attempts to avoid overtreatment of clinically indolent PCa, the method to differentiate patients with clinically significant versus indolent disease remains controversial. Common selection criteria for AS includes a repeat prostate biopsy to confirm the initial pathology. MP-MRI has the poten-