Dirk Beyersdorff

Detection rate of PET/CT in patients with biochemical relapse of prostate cancer using [ 68 Ga]PSMA I&T and comparison with published data of [ 68 Ga]PSMA HBED-CC

PurposeTo determine the detection rate of PET/CT in biochemical relapse of prostate cancer using [68Ga]PSMA I&T and to compare it with published detection rates of [68Ga]PSMA HBED-CC.MethodsWe performed a retrospective analysis in 83 consecutive patients with documented biochemical relapse after prostatectomy. All patients underwent whole body [68Ga]PSMA I&T PET/CT. PET/CT images were evaluated for presence of local recurrence, lymph node metastases, and distant metastases. Proportions of positive PET/CT results were calculated for six subgroups with increasing prostate specific antigen (PSA) levels (<0.5 ng/mL, 0.5 to <1.0 ng/mL, 1.0 to <2.0 ng/mL, 2.0 to <5.0 ng/mL, 5.0 to <10.0, ≥10.0 ng/mL). Detection rates of [68Ga]PSMA I&T were statistically compared with published detection rates of [68Ga]PSMA HBED-CC using exact Fisher’s test.ResultsMedian PSA was 0.81 (range: 0.01 – 128) ng/mL. In 58/83 patients (70 %) at least one [68Ga]PSMA I&T positive lesion was detected. Local recurrent cancer was present in 18 patients (22 %), lymph node metastases in 29 patients (35 %), and distant metastases in 15 patients (18 %). The tumor detection rate was positively correlated with PSA levels, resulting in detection rates of 52 % (<0.5 ng/mL), 55 % (0.5 to <1.0 ng/mL), 70 % (1.0 to <2.0 ng/mL), 93 % (2.0 to <5.0 ng/mL), 100 % (5.0 to <10.0 ng/mL), and 100 % (≥10.0 ng/mL). There was no significant difference between the detection rate of [68Ga]PSMA I&T and published detection rates of [68Ga]PSMA HBED-CC (all p>0.05).Conclusions[68Ga]PSMA I&T PET/CT has high detection rates of recurrent prostate cancer that are comparable to [68Ga]PSMA HBED-CC.

Prediction of Significant Prostate Cancer at Prostate Biopsy and Per Core Detection Rate of Targeted and Systematic Biopsies Using Real-Time Shear Wave Elastography

Introduction: Prostate cancer (PCa) detection is accompanied by overdiagnosis and mischaracterization of PCa. Therefore, new imaging modalities like shear wave elastography (SWE) are required. Aim: The aim of this study was to evaluate per-core detection rates (DRs) of targeted biopsies and systematic biopsies and to test if SWE findings can predict presence of clinically significant PCa (csPCa) at biopsy. Patients and Methods: Overall, 95 patients scheduled for prostate biopsy in our center underwent SWE. SWE findings were classified into suspicious or normal. Targeted biopsies were taken in up to 3 SWE-suspicious areas. csPCa was defined as the presence of Gleason pattern ≥4, level of prostate-specific antigen ≥10 ng/ml or >2 positive cores. Results: Overall DR for csPCa in our study cohort was 40%. Per-core DR for exclusively SWE-targeted cores versus systematic samples cores was 10.5 vs. 8.6% (p = 0.3). In the logistic regression models, individuals with suspicious SWE findings are at 6.4-fold higher risk of harboring csPCa (p = 0.03). Gain in predictive accuracy was 2.3% (0.82 vs. 0.84, p = 0.01). Conclusions: Presence of suspicious SWE findings is an independent predictor of csPCa. Therefore, SWE may be helpful in selecting patients for biopsy. Nonetheless, per-core DR for SWE-targeted cores was not statistically significant higher than DR of systematic sampled cores. Therefore, additional systematic biopsy is mandatory.

Non-metastatic castrate-resistant prostate cancer: a call for improved guidance on clinical management

BackgroundGuidelines on the clinical management of non-metastatic castrate-resistant prostate cancer (nmCRPC) generally focus on the need to continue androgen deprivation therapy and enrol patients into clinical trials of investigational agents. This guidance reflects the lack of clinical trial data with established agents in the nmCRPC patient population and the need for trials of new agents.AimTo review the evidence base and consider ways of improving the management of nmCRPC.ConclusionUpon the development of castrate resistance, it is essential to rule out the presence of metastases or micrometastases by optimising the use of bone scans and possibly newer procedures and techniques. When nmCRPC is established, management decisions should be individualised according to risk, but risk stratification in this diverse population is poorly defined. Currently, prostate-specific antigen (PSA) levels and PSA doubling time remain the best method of assessing the risk of progression and response to treatment in nmCRPC. However, optimising imaging protocols can also help assess the changing metastatic burden in patients with CRPC. Clinical trials of novel agents in nmCRPC are limited and have problems with enrolment, and therefore, improved risk stratification and imaging may be crucial to the improved management. The statements presented in this paper, reflecting the views of the authors, provide a discussion of the most recent evidence in nmCRPC and provide some advice on how to ensure these patients receive the best management available. However, there is an urgent need for more data on the management of nmCRPC.

Anterior Localization of Prostate Cancer Suspicious Lesions in 1,161 Patients Undergoing Magnetic Resonance Imaging/Ultrasound Fusion Guided Targeted Biopsies

Purpose Based on findings in transrectal ultrasound guided biopsy series standard sampling of the prostate targets the posterior/peripheral zone. However, a substantial proportion of lesions that are prostate cancer suspicious and PI‐RADS™ (Prostate Imaging Reporting and Data System) 3 or greater on magnetic resonance imaging is located in the anterior segment of the prostate, requiring deeper placement and targeting of the biopsy needle. Materials and Methods Overall 1,161 patients underwent magnetic resonance imaging/ultrasound fusion guided targeted biopsy. Prostate cancer suspicious lesions on magnetic resonance imaging were dichotomized into anterior vs posterior prostate segments. Patients were stratified by the number of prior negative systematic biopsy sessions. Descriptive statistics included the frequency and proportion of multiparametric magnetic resonance imaging findings and corresponding histological results. Results Targeted biopsy was performed in 513 patients (44%) who were systematic biopsy naïve, 396 (34%) with 1 prior negative systematic biopsy and 252 (22%) with 2 or more prior negative systematic biopsies. When patients were stratified by the number of prior systematic biopsy sessions, the proportion with exclusively anterior, PI‐RADS 3 or greater lesions on magnetic resonance imaging increased from 3.5% to 9.1% (p = 0.006). Unfavorable 3 + 4 and 4 + 3 or greater primary Gleason patterns were identified in exclusively anterior vs posterior lesions in 31% vs 21% of the 448 patients, of whom 64 had exclusively anterior and 384 had posterior PI‐RADS 3 or greater lesions, respectively, on magnetic resonance imaging. Multivariable logistic regression analyses confirmed these findings. Conclusions After multiple previous negative systematic biopsy sessions the proportion of anterior lesions on magnetic resonance imaging increased. Such lesions harbored a greater amount of unfavorable prostate cancer. Therefore, image guidance for precise targeting should be considered, especially after initially negative transrectal ultrasound guided systematic biopsy.

Accuracy of multiparametric MR imaging with PI-RADS V2 assessment in detecting infiltration of the neurovascular bundles prior to prostatectomy

OBJECTIVES To evaluate the accuracy of assessment of neurovascular bundle (NVB) infiltration using multiparametric magnetic resonance imaging (mpMRI) and PI-RADS V2 prior to prostatectomy. METHODS The ethics committee approved this retrospective study with waiver of informed consent. N=198 consecutive patients with biopsy proved cancer underwent standardized mpMRI at 3T prior to surgery. NVB infiltration was assessed for each side (a total of 396). Maximum PI-RADS V2 scores were determined for the posterolateral areas adjacent to the NVBs. Imaging results were correlated with postoperative pathology and standard descriptive statistics were calculated. RESULTS Overall T-staging sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of mpMRI were 64.4%, 89.2%, 82.4%, 76.2% and 78.3%, respectively. In 396 cases NVB infiltration was predicted with 75.3%, 94.0%, 80.2%, 92.1 % and 89.4 % sensitivity, specificity, PPV, NPV and accuracy, respectively. Analyses of 396 NVB and their adjacent PI-RADS V2 scores with pathology revealed significantly more NVB-infiltrations in suspect scores of 5 and 4 vs. uncertain scores of 3-1 (81/264 vs. 16/132, p=0.0001). Considering scores higher than 3 as a criterion of infiltration demonstrated moderate sensitivity and poor specificity (83.5% and 38.8%, respectively). Interobserver agreement of a second reading of a random sample was good (κ=0.64) for NVB infiltrations and moderate (κ=0.59) for PI-RADS V2. CONCLUSIONS Assessment of infiltration of the neurovascular bundles using mpMRI has valuable diagnostic performance, yet PI-RADS V2 Scores demonstrate limited eligibility. Combined findings offer crucial information for the planning of prostatectomy.

Preoperative evaluation of pelvine lymph node metastasis in high risk prostate cancer with intravoxel incoherent motion (IVIM) MRI

OBJECTIVES To evaluate benign and malignant pelvine lymph nodes in prostate cancer patients with biexponential intravoxel incoherent motion (IVIM) MRI of the prostate prior to radical prostatectomy. METHODS The ethics committee approved this retrospective study with waiver of informed consent. From February 2012 to November 2013 43 patients with histopathologically proven prostatic cancer were included. All patients were examined applying a standardized MRI protocol including IVIM diffusion weighted imaging with multiple b-values ranging from 0 to 950 s/mm². MR imaging was performed one day prior to radical prostatectomy. Thereafter, extended lymph node resection was performed. For each MRI all visible lymph nodes were registered and calculated as individual regions of interest. These findings were correlated with postoperative pathology. The apparent diffusion coefficient ADC, the diffusion coefficient D and the perfusion fraction f were calculated from IVIM DWI using a biexponential fit. RESULTS A total of 120 lymph nodes were detected on MRI. 95 of these were determined as benign and 25 as malignant. The average ADC was significantly lower in malignant compared to benign lymph nodes (0.88 × 10-³ vs 1.67 × 10-³ mm²/s, p < 0.001). Likewise, the average diffusion coefficient D was significantly lower in lymph node metastasis (0.54 × 10-³ vs 1.10 × 10-³ mm²/s, p < .001). The signal rate due to perfusion was significantly higher in malignant compared to benign nodes (33.4% vs. 27.1%, p = 0.02). CONCLUSIONS Applying biexponential IVIM MRI demonstrates significant differences in diffusion parameters ADC and D, as well as in the perfusion fraction f for benign and malignant lymph nodes. Therefore, IVIM might help to further improve the preoperative assessment of lymph nodes in MRI.

MP38-16 COMBINING 68GA-PSMA-PET AND MULTIPARAMETRIC MRI: ENHANCING THE ABILITY TO DETECT INTRAPROSTATIC TUMOUR LESIONS AND PATIENTS ELIGIBLE FOR FOCAL TREATMENT ?

protocol. A suspicious mpMRI lesion was defined as having a Prostate Imaging Reporting and Data System (PI-RADS) score 4, whereas clinically significant cancer was defined as cancer with Gleason grade 3+4. Descriptive statistics and two-way t-tests were performed with STATA 14. RESULTS: Of 355 patients, 49.3% (175/355) had a suspicious mpMRI lesion and 47.9% (170/355) of the cohort had significant cancer on biopsy overall. There was moderate sensitivity (67.1%), negative predictive value (71.3%), specificity (69.7%) and positive predictive value (60.9%) for the mpMRI detection of significant cancer in the same or neighbouring location at biopsy. Of the 56 patients with significant cancer but non-suspicious mpMRI (PI-RADS <4), 66.1% (37/56) were Gleason 3+4 and 32.1% (18/56) were matched to a PI-RADS 3 lesion. For Gleason grade 4+4 cancers, 90.4% (47/52) had a corresponding mpMRI lesion with PI-RADS score 4. Examining all patients with significant cancer at biopsy matching to a suspicious mpMRI lesion, 84.2% (96/114) were the highest Gleason grade found on biopsy. The mean size of suspicious mpMRI lesions with significant cancer on biopsy was significantly larger than those with Gleason 3+3 cancer or no cancer at biopsy (16.7 mm vs.13.9 mm respectively; p1⁄40.03). CONCLUSIONS: When precisely mapping the location of mpMRI lesions to positive prostate biopsy cores for significant cancer, a moderate sensitivity and positive predictive value was found suggesting that concomitant systematic biopsy cannot be abandoned. PI-RADS 4 lesions had excellent prediction of high-grade cancers at biopsy. Larger mpMRI lesions may yield more clinically significant cancers on biopsy.

MP03-12 ACCURACY OF MULTIPARAMETRIC MR IMAGING WITH PI-RADS V2 ASSESSMENT IN DETECTING INFILTRATIONS OF THE NEUROVASCULAR BUNDLES PRIOR TO PROSTATECTOMY

RESULTS: Prostate cancers were identified in 52% of cases. Among patients diagnosed with prostate cancer, 80% were clinically significant. The detection rates of csPCa using FB when a PIRADS 3, 4, or 5 index lesion was present on mpMRI were 6%, 46%, and 66%, respectively. PI-RADS v2 score had a predictive accuracy (AUC) of 0.79 for csPCa detection. Institutional experience over time, MRI-estimated prostate volume, and PI-RADS v2 score were independent predictors of success at detecting csPCa. CONCLUSIONS: Since FB is a highly technical and experience-driven process, development of internal quality measures to assess the institutional learning curve and the quality of PI-RADS v2 scoring is critical with adoption of this technology.