Prostate cancer diagnostics: innovative imaging in case of multiple negative biopsies

Can 3D Multiparametric Ultrasound Imaging Predict Prostate Biopsy Outcome?

OBJECTIVES

To assess the value of 3D multiparametric ultrasound imaging, combining hemodynamic and tissue stiffness quantifications by machine learning, for the prediction of prostate biopsy outcomes.

METHODS

After signing informed consent, 54 biopsy-naïve patients underwent a 3D dynamic contrast-enhanced ultrasound (DCE-US) recording, a multi-plane 2D shear-wave elastography (SWE) scan with manual sweeping from base to apex of the prostate, and received 12-core systematic biopsies (SBx). 3D maps of 18 hemodynamic parameters were extracted from the 3D DCE-US quantification and a 3D SWE elasticity map was reconstructed based on the multi-plane 2D SWE acquisitions. Subsequently, all the 3D maps were segmented and subdivided into 12 regions corresponding to the SBx locations. Per region, the set of 19 computed parameters was further extended by derivation of eight radiomic features per parameter. Based on this feature set, a multiparametric ultrasound approach was implemented using five different classifiers together with a sequential floating forward selection method and hyperparameter tuning. The classification accuracy with respect to the biopsy reference was assessed by a group-k-fold cross-validation procedure, and the performance was evaluated by the Area Under the Receiver Operating Characteristics Curve (AUC).

RESULTS

Of the 54 patients, 20 were found with clinically significant prostate cancer (csPCa) based on SBx. The 18 hemodynamic parameters showed mean AUC values varying from 0.63 to 0.75, and SWE elasticity showed an AUC of 0.66. The multiparametric approach using radiomic features derived from hemodynamic parameters only produced an AUC of 0.81, while the combination of hemodynamic and tissue-stiffness quantifications yielded a significantly improved AUC of 0.85 for csPCa detection (p-value < 0.05) using the Gradient Boosting classifier.

CONCLUSIONS

Our results suggest 3D multiparametric ultrasound imaging combining hemodynamic and tissue-stiffness features to represent a promising diagnostic tool for biopsy outcome prediction, aiding in csPCa localization.

Enhanced Transrectal Ultrasound, Real-Time Sonoelastography, and Contrast-Enhanced Transrectal Ultrasound in Heavily Prescreened Chinese Men With Naive and Repetitive Biopsy: A Comparison of Detection Rate of Prostate Cancer Per Man and Per Lesion

ABSTRACT

Multiparametric magnetic resonance imaging and targeted biopsy have been widely accepted as the most accurate technique to detect localize prostate cancer. It is a time-consuming and expensive option and may not be widely available in China, making ultrasound the first choice for the detection of prostate cancer. In this current retrospective study, the diagnostic values of enhanced transrectal ultrasound, contrast-enhanced transrectal ultrasound, and real-time sonoelastography were evaluated. Symptomatic 315 men older than 40 years with prostate-specific antigen level greater than 4.0 ng/mL, with abnormal digital rectal examinations, and with suspicious lesions for prostate cancer under enhanced transrectal ultrasound included in the study. Enhanced transrectal ultrasound was suspicious in all 315 men, with 189 of 315 men with prostate cancer according to the prostate biopsy report. Sonoelastography was suspicious in 294 of 315 men, with 166 of 315 men with prostate cancer according to the prostate biopsy report. Contrast-enhanced transrectal ultrasound was suspicious in 221 of 315 men, with 159 of 315 men with prostate cancer according to the prostate biopsy report. Real-time sonoelastography alone and contrast-enhanced transrectal ultrasound alone were missed in 27 (11%) and 39 (15%) lesions to report cancer through biopsies. Working area for enhanced transrectal ultrasound, real-time sonoelastography, and contrast-enhanced transrectal ultrasound for detection of prostate cancer were 0 to 1 diagnostic confidence, 0.11 to 0.895 diagnostic confidence, and 0.39 to 0.63 diagnostic confidence respectively. Real-time sonoelastography and contrast-enhanced transrectal ultrasound may improve the detection of prostate cancer in men with suspicious prostate lesions under enhanced transrectal ultrasound (Level of Evidence: III; Technical Efficacy Stage: 2).

68Ga-PSMA PET/CT Imaging Predicting Intraprostatic Tumor Extent, Extracapsular Extension and Seminal Vesicle Invasion Prior to Radical Prostatectomy in Patients with Prostate Cancer

Purpose

⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA) ligand positron emission tomography/computed tomography (PET/CT) has shown promising results in patients with biochemical recurrence after primary therapy for prostate cancer. In this study, we evaluated the usefulness of PSMA I&T (imaging and therapy) PET/CT prior to radical prostatectomy.

Methods

The study population consisted of 21 patients with prostate cancer who underwent ⁶⁸Ga-PSMA I&T PET/CT before either open or laparoscopic radical prostatectomy. Intraprostatic tumor extent, extracapsular extension (ECE) and seminal vesicle invasion (SVI) were assessed on the PET/CT scans. Tracer uptake was quantified in terms of standardized uptake values (SUVs). Imaging findings were correlated with final whole-gland histopathology.

Results

Of the 21 patients, two had T stage 2b disease, nine stage 2c, six stage 3a and four stage 3b. The median Gleason score was 7. The SUV_mean of the primary tumors was 9.5 ± 8.8. SUV_mean was higher in tumors with ECE than in organ-confined tumors (13.8 ± 11.0 vs. 5.6 ± 3.2, p = 0.029). Peak tracer uptake was significantly positively correlated with Gleason score (r_s = 0.49, p = 0.025). Sensitivity, specificity, positive predictive value and negative predictive value were, respectively, 94.7%, 75.0%, 97.3% and 60.0% for tumor infiltration of an individual prostate lobe, 75.0%, 100.0%, 100.0% and 97.4% for SVI, and 90.0%, 90.9%, 90.0% and 90.9% for ECE, using an angulated contour of the prostate as the criterion. Tumor volume derived from ⁶⁸Ga-PSMA I&T PET/CT was significantly correlated with preoperative prostate-specific antigen value (r_p = 0.75, p < 0.001) and tumor volume on histopathology (r_p = 0.45, p = 0.039).

Conclusions

⁶⁸Ga-PSMA I&T PET/CT prior to radical prostatectomy can contribute to presurgical local staging of prostate cancer. In this pilot study, ⁶⁸Ga-PSMA I&T PET/CT showed promising results for prediction of lobe infiltration, ECE and SVI.

Anticancer effect of deoxypodophyllotoxin induces apoptosis of human prostate cancer cells

Deoxypodophyllotoxin (DPPT) is extracted and separated from citrus-related plants, including Podophyllum (P.) peltatum, P. pleianthum, P. emodi (also called P. hexandrum) and Diphylleia grayi. DPPT has significant antitumor and antiviral activity. However, due to its strong toxicity and side effects, its use is limited in practical applications. The in vitro antitumor efficacy of DPPT on human prostate cancer (PCa) cells remains to be determined. The present study investigated the anticancer effect of DPPT on human PCa cells and its potential mechanism. The data revealed that DPPT markedly reduced cell proliferation and activated the caspase-3 expression level by an increase in apoptotic cell death in DU-145 cells. In addition, treatment with DPPT markedly downregulated the levels of phosphorylated Akt and activated the p53/B-cell lymphoma 2 associated X protein (Bax)/phosphatase and tensin homolog (PTEN) signaling pathway in DU-145 cells, suggesting that caspase-mediated pathways were involved in DPPT-induced apoptosis. The present study suggested the role of DPPT as a novel chemotherapeutic drug for human PCa, which may function through the Akt/p53/Bax/PTEN signaling pathway.

Direct Comparison of Targeted MRI-Guided Biopsy with Systematic Transrectal Ultrasound-Guided Biopsy in Patients with Previous Negative Prostate Biopsies

Objective: To directly compare the diagnostic performance of targeted MRI-guided biopsy (MR-GB) and systematic transrectal ultrasound-guided biopsy (TRUS-GB). Methods: Thirty-five patients with at least one negative TRUS-GB, persistently elevated or rising prostate-specific antigen and a lesion suspicious for prostate cancer (PC) on multiparametric MRI (mpMRI) scored by using the Prostate Imaging Reporting and Data System (PI-RADS) were included. A median of three targeted biopsies per lesion were obtained and systematic TRUS-GB was performed subsequently by an independent urologist without knowledge of the MRI findings. Definite pathology reports were analyzed for anatomical location and criteria of clinical significance. Results: The tumor detection rate was significantly higher with MR-GB compared with TRUS-GB (16/35, 46% and 8/35, 23%, respectively, p < 0.05). MR-GB detected PC in all patients with positive TRUS-GB. All tumors detected by MR-GB exhibited at least one criterion of clinical significance. PC lesions showed a significantly higher PI-RADS sum score compared with benign lesions. Conclusions: MR-GB is more effective compared with TRUS-GB in detecting clinically significant PC in men after previous negative TRUS-GB. PI-RADS scores give additional information and could be part of the decision-making process when considering retrial biopsy. Additional systematic biopsy can be omitted in patients undergoing targeted MR-GB.

Impact of Real-Time Elastography versus Systematic Prostate Biopsy Method on Cancer Detection Rate in Men with a Serum Prostate-Specific Antigen between 2.5 and 10 ng/mL

The actual gold standard for the diagnosis of prostate cancer includes the serum prostate-specific antigen, the digital rectal examination, and the ultrasound-guided systematic prostate biopsy sampling. In the last years, the real-time elastography has been introduced as an imaging technique to increase the detection rate of prostate cancer and simultaneously reduce the number of biopsies sampled for a single patient. Here, we evaluated a consecutive series of 102 patients with negative digital-rectal examination and transrectal ultrasound, and prostate-specific antigen value ranging between 2.5 ng/mL and 10 ng/mL, in order to assess the impact of real-time elastography versus the systematic biopsy on the detection of prostate cancer. We found that only 1 out of 102 patients resulted true positive for prostate cancer when analysed with real-time elastography. In the other 6 cases, real-time elastography evidenced areas positive for prostate cancer, although additional neoplastic foci were found using systematic biopsy sampling in areas evidenced by real-time elastography as negative. Although additional studies are necessary for evaluating the effectiveness of this imaging technique, the present study indicates that the limited accuracy, sensitivity, and specificity do not justify the routine application of real-time elastography in prostate cancer detection.