Magnetic resonance imaging-transrectal ultrasound fusion image-guided prostate biopsy: Current status of the cancer detection and the prospects of tailor-made medicine of the prostate cancer

Cost-Effectiveness of Annual Prostate MRI and Potential MRI-Guided Biopsy After Prostate-Specific Antigen Test Results

Importance

Magnetic resonance imaging (MRI) and potential MRI-guided biopsy enable enhanced identification of clinically significant prostate cancer. Despite proven efficacy, MRI and potential MRI-guided biopsy remain costly, and there is limited evidence regarding the cost-effectiveness of this approach in general and for different prostate-specific antigen (PSA) strata.

Objective

To examine the cost-effectiveness of integrating annual MRI and potential MRI-guided biopsy as part of clinical decision-making for men after being screened for prostate cancer compared with standard biopsy.

Design, Setting, and Participants

Using a decision analytic Markov cohort model, an economic evaluation was conducted projecting outcomes over 10 years for a hypothetical cohort of 65-year-old men in the US with 4 different PSA strata (<2.5 ng/mL, 2.5-4.0 ng/mL, 4.1-10.0 ng/mL, >10 ng/mL) identified by screening through Monte Carlo microsimulation with 10 000 trials. Model inputs for probabilities, costs in 2020 US dollars, and quality-adjusted life-years (QALYs) were from the literature and expert consultation. The model was specifically designed to reflect the US health care system, adopting a federal payer perspective (ie, Medicare).

Exposures

Magnetic resonance imaging with potential MRI-guided biopsy and standard biopsy.

Main Outcomes and Measures

Incremental cost-effectiveness ratios (ICERs) using a willingness-to-pay threshold of $100 000 per QALY was estimated. One-way and probabilistic sensitivity analyses were performed.

Results

For the 3 PSA strata of 2.5 ng/mL or greater, the MRI and potential MRI-guided biopsy strategy was cost-effective compared with standard biopsy (PSA 2.5-4.0 ng/mL: base-case ICER, $21 131/QALY; PSA 4.1-10.0 ng/mL: base-case ICER, $12 336/QALY; PSA >10.0 ng/mL: base-case ICER, $6000/QALY). Results varied depending on the diagnostic accuracy of MRI and potential MRI-guided biopsy. Results of probabilistic sensitivity analyses showed that the MRI and potential MRI-guided biopsy strategy was cost-effective at the willingness-to-pay threshold of $100 000 per QALY in a range between 76% and 81% of simulations for each of the 3 PSA strata of 2.5 ng/mL or more.

Conclusions and Relevance

This economic evaluation of a hypothetical cohort suggests that an annual MRI and potential MRI-guided biopsy was a cost-effective option from a US federal payer perspective compared with standard biopsy for newly eligible male Medicare beneficiaries with a serum PSA level of 2.5 ng/mL or more.

Image-guided prostate biopsy robots: A review

At present, the incidence of prostate cancer (PCa) in men is increasing year by year. So, the early diagnosis of PCa is of great significance. Transrectal ultrasonography (TRUS)-guided biopsy is a common method for diagnosing PCa. The biopsy process is performed manually by urologists but the diagnostic rate is only 20%-30% and its reliability and accuracy can no longer meet clinical needs. The image-guided prostate biopsy robot has the advantages of a high degree of automation, does not rely on the skills and experience of operators, reduces the work intensity and operation time of urologists and so on. Capable of delivering biopsy needles to pre-defined biopsy locations with minimal needle placement errors, it makes up for the shortcomings of traditional free-hand biopsy and improves the reliability and accuracy of biopsy. The integration of medical imaging technology and the robotic system is an important means for accurate tumor location, biopsy puncture path planning and visualization. This paper mainly reviews image-guided prostate biopsy robots. According to the existing literature, guidance modalities are divided into magnetic resonance imaging (MRI), ultrasound (US) and fusion image. First, the robot structure research by different guided methods is the main line and the actuators and material research of these guided modalities is the auxiliary line to introduce and compare. Second, the robot image-guided localization technology is discussed. Finally, the image-guided prostate biopsy robot is summarized and suggestions for future development are provided.

Cribriform pattern and intraductal carcinoma of the prostate can have a clinicopathological impact, regardless of their percentage and/or number of cores

Cribriform pattern and intraductal carcinoma of the prostate (IDC-P) are widely accepted as poor prognostic factors in prostate cancer. However, it remains unclear to what extent the presence of these morphological features in prostate biopsy specimens, as diagnosed by hematoxylin-eosin-stained specimens only, affects the clinicopathological impact. In this study, we summarized the characteristics of the cribriform pattern and IDC-P in 850 prostate biopsy cases. The results showed a statistically significant increase in the incidence of cribriform pattern and IDC-P as grade group (GG) increased (especially in cases ≥ GG4, Chi-square test P < 0.001). The independent risk factors for cribriform pattern and IDC-P in biopsy specimens in the multivariate logistic regression analysis were the former GG, presence of IDC-P, lesion length of the highest GG core, latter GG, presence of the cribriform pattern, number of biopsies obtained, and number of highest GG core. Overall, 125 cases in which radical prostatectomy was conducted after biopsy were selected for further analysis. Multivariate logistic regression analysis using biopsy and surgical specimens confirmed that the presence of the cribriform pattern and IDC-P in biopsy specimens were independent risk factors for lymph node metastasis (odds ratios [95% confidence interval] were 6.54 [1.15-37.05] for the cribriform pattern and 23.71 [1.74-322.42] for IDC-P). The presence of the cribriform pattern and/or IDC-P in a biopsy specimen was a significant factor, even if only partially present, indicating lymph node metastasis. However, further validation is required to predict poor prognostic factors more accurately.

Fusion versus cognitive MRI-guided prostate biopsies in diagnosing clinically significant prostate cancer

Objective:

This study assesses whether fusion or cognitive magnetic resonance imaging (MRI)-guided prostate targeted and systematic transperineal biopsies (TPB) increase detection of clinically significant prostate cancer (csPCa).

Materials and Methods:

A retrospective analysis was completed of patients (2018–2020) undergoing 3-Tesla multiparametric prostate MRI informing targeted (either cognitive or MIM software fusion approach) and systematic TPB. ISUP (International Society of Urological Pathology) grade group ⩾ 2 was considered csPCa.

Results:

A total of 355 cases from 4 urologists were included; 131 were fusion and 224 were cognitive MRI-guided biopsies. Of all csPCa found, 86.8% ( n = 171) of cases were confirmed to be at the MRI-indicated location and 11.6% were found as part of active surveillance. In all, 45.0% of the fusion group were found to have csPCa, compared to 62.05% ( n = 139) in the cognitive group ( p = 0.002). csPCa detection rates varied between urologists (41% to 78%, p < 0.001), so a subgroup analysis was performed on Urologist A; 45.0% of fusion and 41.3% of cognitive biopsies had csPCa ( p = 0.644). Multinomial logistic regression analysis showed that biopsy type, being on active surveillance, number of biopsy cores, iPSA (initial Prostate Specific Antigen) value or PIRADS (Prostate Imaging-Reporting and Data System) score made no significant difference in whether csPCa was found.

Conclusion:

Cognitive and fusion targeting had similar csPCa detection rates. Further prospective studies would be beneficial to validate these findings.

Level of evidence:

2b (according to Oxford Centre for Evidence-Based Medicine)

Effect of Sedation Anesthesia With Intravenous Propofol on Transrectal Ultrasound-Guided Prostate Biopsy Outcomes

BACKGROUND

Sedation anesthesia during transrectal ultrasound (TRUS)-guided prostate biopsy is known to decrease patient pain and anxiety, but little is known whether it affects the procedure's prostate cancer detection and complication rates. This study aimed to determine the effect of sedation anesthesia with intravenous (IV) propofol on TRUS-guided prostate biopsy outcomes.

METHODS

A retrospective analysis of 2,119 patients who underwent TRUS-guided prostate biopsy between November 2009 and February 2019 was undertaken. The patients were divided into two groups: patients who underwent sedation anesthesia with IV propofol and patients who underwent local anesthesia with intrarectal lidocaine gel instillation. Cancer detection and complication rates were compared between the two groups. Univariate and multivariate binary logistic regression and multinomial logistic regression analyses were conducted to investigate the effects of sedation anesthesia with IV propofol on prostate cancer detection and complication rates.

RESULTS

The cancer detection rate of patients in the sedation group was 34.0%, whereas it was 29.2% in the local group (P = 0.024). Multivariate logistic regression analysis regarding factors associated with cancer detection rate after TRUS-guided prostate biopsy in patients with prostate specific antigen (PSA) < 10 showed that IV propofol usage, age, PSA density and core length were significant factors. Multivariate logistic regression analysis regarding factors associated with complications (voiding dysfunction, bleeding and infection) showed that IV propofol usage, age and prostate size were significant factors for voiding dysfunction.

CONCLUSION

Sedation anesthesia with IV propofol during TRUS-guided prostate biopsy was associated with a higher cancer detection rate than local anesthesia with intrarectal lidocaine gel instillation. Cancer detection rate could be an important factor to consider when selecting for the optimal anesthesia for TRUS-guided prostate biopsy.

Feasibility of magnetic resonance imaging-ultrasound guided high-dose-rate brachytherapy for localized prostate cancer: Preliminary results from a prospective study

OBJECTIVE

This study aimed to investigate preliminary outcomes of a prospective trial of magnetic resonance imaging-ultrasound fusion-guided ultrafocal high-dose-rate brachytherapy in localized prostate cancer.

METHODS

In our prospective study, data from patients who underwent this treatment between April 1, 2020 and March 31, 2021 were analyzed. In the procedure, the applicator needle was inserted through the perineum to target the lesion on the multiparametric magnetic resonance imaging, which was fused onto the transrectal ultrasound image. The prescription dose was set at a single fraction of 19 Gy. Data from patients who received whole-gland high-dose-rate brachytherapy were extracted and compared with data from patients who received ultrafocal high-dose-rate brachytherapy, to evaluate the frequency of acute adverse events.

RESULTS

Eight patients underwent ultrafocal high-dose-rate brachytherapy with a median observation period of 7.75 months (range 5.96-15.36 months). No acute genitourinary or gastrointestinal adverse events were observed in this cohort. The planned procedure was completed in all patients, and no unexpected adverse events were observed; however, prostate-specific antigen failure was detected in one patient. In the 25 patients who underwent whole-gland high-dose-rate brachytherapy, acute genitourinary and gastrointestinal adverse events were observed in 88% and 20% of the patients, respectively. Ultrafocal high-dose-rate brachytherapy was a significant factor in avoiding acute adverse genitourinary events in univariate and multivariate analyses (P < 0.001 and P = 0.032, respectively).

CONCLUSIONS

Magnetic resonance imaging-ultrasound fusion-guided ultrafocal high-dose-rate brachytherapy in localized prostate cancer is a safe and feasible treatment without acute genitourinary and gastrointestinal adverse events. Long-term observation and further investigation are warranted.

Diagnostic performance of fusion (US/MRI guided) prostate biopsy: propensity score matched comparison of elastic versus rigid fusion system

PURPOSE

Many software for US/MRI guided fusion prostate biopsy (FPB), have been developed in the last years. However, there are few data comparing diagnostic accuracy of different fusion systems. We assessed diagnostic performance of elastic (EF) versus rigid fusion (RF) PB in a propensity score matched (PSM) analysis.

METHODS

A total of 314 FPB were prospectively collected from two different centers. All patients were biopsy naïve and all mpMRI reported a single suspicious area. Overall, 211 PB were performed using a RF system and 103 using an EF software. The two groups were compared for the main clinical features. A 1:1 PSM analysis was employed to reduce covariate imbalance to < 10%. Detection rate (DR) for any prostate cancer (PCa) and clinically significant (cs) PCa were compared and stratified for PI-RADS Score. A per target univariable and multivariable regression analyses were applied to identity predictors of anyPCa and csPCa.

RESULTS

After applying the PSM, two cohorts of 83 cases were selected. DR of any PCa cancer and csPCa were comparable between the two cohorts (all p > 0.077) as well as DR of csPCa for every PIRADS score. At univariable regression analysis lesion size, PI-RADS Score, PSA Density and EF system were predictors of any PCa (all p < 0.001); however, at multivariable analysis only PI-RADS Score was independent predictor of any PCa (p = 0.027). At multivariable analysis only PI-RADS score was independent predictor of csPCa.

CONCLUSIONS

Fusion PB guarantees high diagnostic accuracy for csPCa, regardless of the fusion technology. Prospective randomized study is needed to confirm these data.

Development and future prospective of treatment for localized prostate cancer with high-intensity focused ultrasound

High-intensity focused ultrasound (HIFU) was experimentally used for focal therapy for anti-cancer effects in prostate cancer (PC). Focal therapy is a diagnosis-based investigational treatment option for localized PC that cures clinically significant PC (csPC) while preserving the anatomical structures related to urinary and sexual function based on its spread observed using multi-parametric magnetic resonance imaging (mpMRI). The European Association of Urology indicated that the current status of focal therapy for localized PC was an investigational modality and encouraged prospective recording of outcomes and recruitment of suitable patients in 2018. During the last few years, large-population multi- and single-center prospective studies have investigated focal therapy as a treatment strategy for localized PC. In a multicenter prospective study with 5-year follow-up, failure-free survival, which was defined as avoidance of local salvage therapy (surgery or radiotherapy), systemic therapy, metastases, and prostate cancer-specific death, was 88%. In the previous studies, there was no significant influence on urinary function before and at 3 months after the treatment, although transient impairment was reported 1 month after the treatment. Pad- and leak-free continence was preserved in 80-100% of the patients after treatment. Erectile function was significantly impaired in the initial 3 months after treatment compared to the pretreatment values, but it improved 6 months after the focal therapy in the previous reports. Paired comparison studies and cohort studies with long-term follow-up will contribute to verifying this treatment's clinical outcomes for patients with localized PC.

THE ROLE OF THE APPARENT DIFFUSION COEFFICIENT OF THE BIPARAMETRIC MRI AS AN IMAGING MARKER OF PROSTATE CANCER

Prostate cancer (PCa) is the most common malignancy in men. The role of the apparent diffusion coefficient (ADC)of biparametric MRI (biMRI) which is a study without the use of dynamic contrast enhancement (DCE), in detectionof PCa is still not comprehensively investigated.

OBJECTIVE

The goal of the study was to assess the role of ADC of biMRI as an imaging marker of clinically significant PCaMaterials and methods. The study involved 78 men suspected of having PCa. All patients underwent a comprehensive clinical examination, which included multiparametric MRI of the prostate, a component of which was biMRI. TheMRI data was evaluated according to the PIRADS system version 2.1.

RESULTS

The distribution of patients according to the PIRADS system was as follows: 1 point - 9 (11.54 %)patients, 2 points - 12 (15.38 %) patients, 3 points - 25 (32.05 %) patients, 4 points - 19 (24.36 %) patients and5 points - 13 (16.67 %) patients. In a subgroup of patients with 5 points, clinically significant PCa was detected in 100 % of cases. In the subgroup of patients with tumors of 4 points clinically significant PCa was diagnosed in 16of 19 (84.21 %) cases, and in 3 (15.79 %) patients - clinically insignificant tumor. In the subgroup of patients with3 points, clinically significant PCa was diagnosed in 11 of 25 (44.0 %) cases, in 8 (32.0 %) patients - clinicallyinsignificant tumor and in 6 (24.0 %) patients - benign prostatic hyperplasia. PCa with a score of 7 on the Gleasonscale showed significantly lower mean values of ADC of the diffusion weighted MRI images compared to tumors witha score of < 7 on the Gleason scale: (0.86 ± 0.07) x 103 mm2/s vs (1.08 ± 0.04) x 103 mm2/s (р < 0.05).

CONCLUSIONS

The obtained results testify to the high informativeness of biMRI in the diagnosis of prostate cancer.The use of ADC allowed to differentiate clinically significant and insignificant variants of the tumor, as well asbenign changes in prostate tissues and can be considered as a potential imaging marker of PCa.

Prostate cancer detection by targeted prostate biopsy using the 3D Navigo system: a prospective study

PURPOSE

The 3D Navigo™ system is a magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS) fusion device for prostate targeted biopsies (TB). Our aim was to evaluate the clinically significant prostate cancer (CSC) detection rate of TB using the 3D Navigo™ system.

METHODS

Patients who underwent TB with the 3D Navigo™ system in our center between June 2014 and May 2018 were prospectively included, excluding those who have previously received treatment for prostate cancer. A 3-Tesla MRI imaging was performed before biopsies; findings were reported according to the Prostate Imaging Reporting and Data System version 2 (PIRADS). CSC was defined by an ISUP score ≥ 2.

RESULTS

304 patients underwent TB. Median age was 66 years (51-84). Median PSA was 7.75 ng/ml (0.6-70.0). Median prostate volume was 45.0 ml (15.9-221.7). PCa and CSC were found in 70.4% (214/304) and 47.7% (145/304) of the patients, respectively. The proportion of patients diagnosed with CSC among those with PCa was 67.8% (145/214). There was a significant risk of having a CSC in case of PIRADS score ≥ 4 and 5 (OR 5.0, 95% CI [2.7-9.2], P < 0.001; OR 3.2, 95% CI [1.8-5.5], P < 0.001). PIRADS score was an independent risk factor of having a CSC (OR 4.19, 95% CI [2.49-7.05], P < 0.001). There was no significant difference between pathological outcomes of TB and RP in paired analysis (P = 0.892). There was a correlation between TB and RP specimens for PCa detection (r = 0.60, P < 0.001).

CONCLUSION

Detecting CSC with MRI-TRUS fusion targeted biopsies using the 3D Navigo™ system is feasible and safe. We found a positive correlation between TB and RP for ISUP scores.

Real-Time Ultrasound Image Fusion with FDG-PET/CT to Perform Fused Image-Guided Fine-Needle Aspiration in Neck Nodes: Feasibility and Diagnostic Value

BACKGROUND AND PURPOSE

New imaging techniques such as hybrid imaging of ultrasound and FDG-PET/CT are available but not yet investigated for node staging. The aim of the study was to evaluate the feasibility and added diagnostic value of real-time image-fused ultrasound-guided fine-needle aspiration with FDG-PET/CT data for node staging.

MATERIALS AND METHODS

Ninety-six patients who were referred for cervical lymph node staging with FDG-PET/CT before ultrasound were prospectively included. After routine ultrasound-guided fine-needle aspiration, all FDG-PET-positive nodes were marked on FDG-PET/CT, and real-time image fusing of ultrasound and FDG-PET/CT was performed using the electromagnetic navigation system PercuNav. Already-punctured nodes were confirmed to be PET-positive, and additional fused-ultrasound-guided fine-needle aspiration was performed in previously missed PET-positive nodes.

RESULTS

Of 96 patients, 87 (91%) patients had suspicious nodes requiring fine-needle aspiration cytology. Ultrasound-guided fine-needle aspiration was performed in 175 nodes. Cytology was inconclusive in 9/175 (5%) nodes, and 85/166 (51%) nodes were malignant. Target planning was performed in 201 PET-positive nodes; 195/201 (97%) of those nodes were fused successfully. Twenty of 175 ultrasound-guided fine-needle aspiration nodes turned out to be FDG-PET-negative, and 149/175 (85%) of the fused ultrasound-guided fine-needle aspiration nodes were confirmed to be FDG-PET-positive. Of 201 PET-positive nodes, 46 (23%) were additionally identified, and fused ultrasound-guided fine-needle aspiration was performed. Cytology was inconclusive in 4/46 nodes (9%), and 13/42 (31%) nodes were malignant.

CONCLUSIONS

Real-time ultrasound image fusion with FDG-PET-positive nodes is feasible in cervical lymph nodes, and fused ultrasound-guided fine-needle aspiration increases the number of malignant nodes detected.

Stereotactic Transcranial Focused Ultrasound Targeting System for Murine Brain Models

An inexpensive, accurate focused ultrasound stereotactic targeting method guided by pretreatment magnetic resonance imaging (MRI) images for murine brain models is presented. An uncertainty of each sub-component of the stereotactic system was analyzed. The entire system was calibrated using clot phantoms. The targeting accuracy of the system was demonstrated with an in vivo mouse glioblastoma (GBM) model. The accuracy was quantified by the absolute distance difference between the prescribed and ablated points visible on the pre treatment and posttreatment MR images, respectively. A precalibration phantom study ( N = 6 ) resulted in an error of 0.32 ± 0.31, 0.72 ± 0.16, and 1.06 ± 0.38 mm in axial, lateral, and elevational axes, respectively. A postcalibration phantom study ( N = 8 ) demonstrated a residual error of 0.09 ± 0.01, 0.15 ± 0.09, and 0.47 ± 0.18 mm in axial, lateral, and elevational axes, respectively. The calibrated system showed significantly reduced ( ) error of 0.20 ± 0.21, 0.34 ± 0.24, and 0.28 ± 0.21 mm in axial, lateral, and elevational axes, respectively, in the in vivo GBM tumor-bearing mice ( N = 10 ).

Development and validation of a nomogram for predicting prostate cancer in men with prostate-specific antigen grey zone based on retrospective analysis of clinical and multi-parameter magnetic resonance imaging/transrectal ultrasound fusion-derived data

Background

Urologists face a dilemma when deciding whether prostate biopsy is required for patients with prostate-specific antigen (PSA) levels in the grey zone (4 to 10 ng/mL).

Methods

We retrospectively analyzed data from consecutive patients with PSA levels in grey zone, who underwent targeted multiparametric magnetic resonance imaging (MP-MRI)/transrectal ultrasound (TRUS) fusion biopsy with elastography between November 2017 and December 2019 in our hospital. The patientse data including age, PSA, fPSA (free PSA), fPSA/PSA, PSA density (PSAD), prostate volume, elastography Q-analysis score (EQS), and prostate imaging-reporting and data system (PI-RADS) score were collected. The nomogram was built using logistic regression and the final cohort of patients was randomly divided into a training cohort (70%) and a validation cohort (30%) by R software. The models were evaluated by receiver operating characteristic curve (ROC) analysis and calibration curve analysis. The nomogram was constructed from the best model.

Results

The final study cohort consisted of 155 patients (training cohort, 109 patients; validation cohort, 46 patients) with PSA in the grey zone, of which 36 patients were pathologically diagnosed with PCa. The EQS model, -EQS model, +EQS model were built. The +EQS model that consisted of fPSA/PSA, EQS, and PI-RADS score had the best PCa diagnostic accuracy (development and validation, 0.783 and 0.781) and probability score (development and validation, 0.939 vs. 0.622). The new nomogram based on this model was constructed, in which fPSA/PSA ratio had the largest impact, followed by PI-RADS and EQS.

Conclusions

Elastography and pre-biopsy MP-MRI has clinical significance for patients with PSA in the grey zone. The new nomogram, which is based on pre biopsy data including serological analysis, PI-RADS score, and EQS, can be helpful for clinical decision-making to avoid unnecessary biopsy.

Proteomic Tissue-Based Classifier for Early Prediction of Prostate Cancer Progression

Although ~40% of screen-detected prostate cancers (PCa) are indolent, advanced-stage PCa is a lethal disease with 5-year survival rates around 29%. Identification of biomarkers for early detection of aggressive disease is a key challenge. Starting with 52 candidate biomarkers, selected from existing PCa genomics datasets and known PCa driver genes, we used targeted mass spectrometry to quantify proteins that significantly differed in primary tumors from PCa patients treated with radical prostatectomy (RP) across three study outcomes: (i) metastasis ≥1-year post-RP, (ii) biochemical recurrence ≥1-year post-RP, and (iii) no progression after ≥10 years post-RP. Sixteen proteins that differed significantly in an initial set of 105 samples were evaluated in the entire cohort (n = 338). A five-protein classifier which combined FOLH1, KLK3, TGFB1, SPARC, and CAMKK2 with existing clinical and pathological standard of care variables demonstrated significant improvement in predicting distant metastasis, achieving an area under the receiver-operating characteristic curve of 0.92 (0.86, 0.99, p = 0.001) and a negative predictive value of 92% in the training/testing analysis. This classifier has the potential to stratify patients based on risk of aggressive, metastatic PCa that will require early intervention compared to low risk patients who could be managed through active surveillance.

Diagnostic Accuracy and Value of Magnetic Resonance Imaging-Ultrasound Fusion Transperineal Targeted and Template Systematic Prostate Biopsy Based on Bi-parametric Magnetic Resonance Imaging

Purpose

The purpose of this study was to investigate the diagnostic value of magnetic resonance imaging (MRI)–ultrasound (US) fusion transperineal targeted biopsy (FTB) and fusion template systematic biopsy (FSB) for prostate cancer (PCa) and clinically significant prostate cancer (csPCa) (intermediate/high grade [Gleason score ≥ 3+4]) based on bi-parametric MRI (bpMRI).

Materials and methods

Retrospectively, we analyzed 300 patients with elevated prostate-specific antigen (≥ 4.0 ng/mL) and/or abnormal findings in a digital rectal examination at the Korea University Hospital. All 300 men underwent bpMRI-US fusion transperineal FTB and FSB in the period from April 2017 to March 2019.

Results

PCas were detected in 158 of 300 men (52.7%), and the prevalence of csPCa was 34.0%. CsPCas were detected in 12 of 102 (11.8%) with Prostate Imaging-Reporting and Data System (PI-RADS) 3, 42 of 92 (45.7%) with PI-RADS 4, respectively; and 45 of 62 (72.6%) men with PI-RADS 5, respectively. BpMRI showed a sensitivity of 95.1% and negative predictive value of 89.6% for csPCa. FTB detected additional csPCa in 33 men (12.9%) compared to FSB. Compared to FTB, FSB detected additional csPCa in 10 men (3.9%).

Conclusion

BpMRI-US FTB and FSB improved detection of PCa and csPCa. The accuracy of bi-parametric MRI is comparable with that of multi-parametric MRI. Further, it is rapid, simpler, cheaper, and no side effects of contrast media. Therefore, it is expected that bpMRI-US transperineal FTB and FSB could be a good alternative to conventional US-guided transrectal biopsy, which is the current gold standard.

Current status and future prospective of focal therapy for localized prostate cancer: development of multiparametric MRI, MRI-TRUS fusion image-guided biopsy, and treatment modalities

Multiparametric magnetic resonance imaging (mpMRI) has been increasingly used to diagnose clinically significant prostate cancer (csPC) because of its usefulness in combination with anatomic and functional data. MRI-targeted biopsy, such as MRI-transrectal ultrasound (TRUS) fusion image-guided prostate biopsy, has high accuracy in the detection and localization of csPC. This novel diagnostic technique contributes to the development of tailor-made medicine as focal therapy, which cures the csPC while preserving the anatomical structures related to urinary and sexual function. In the early days of focal therapy, TRUS-guided systematic biopsy was used for patient selection, and treatment was performed for patients with low-risk PC. With the introduction of mpMRI and mapping biopsy, the treatment range is now determined based on individualized cancer localization. In recent prospective studies, 87.4% of treated patients had intermediate- and high-risk PC. However, focal therapy has two main limitations. First, a randomized controlled trial would be difficult to design because of the differences in pathological features between patients undergoing focal therapy and radical treatment. Therefore, pair-matched studies and/or historical controlled studies have been performed to compare focal therapy and radical treatment. Second, no long-term (≥ 10-year) follow-up study has been performed. However, recent prospective studies have encouraged the use of focal therapy as a treatment strategy for localized PC because it contributes to high preservation of continence and erectile function.

Interventional therapy in malignant conditions of the prostate

Interventional therapies are emerging modalities for the treatment of localized prostate cancer. Their aim is to reduce the morbidity associated with radical therapies (rT) by minimizing damage to non-cancerous tissue, with priority given to sparing key structures such as the neurovascular bundles, external sphincter, bladder neck, and rectum, while maintaining local cancer control. Interventional ablative technologies deliver energy in different ways to destroy cancer cells. The most widely investigated techniques are brachytherapy, external beam radiotherapy, cryotherapy, and high-intensity focused ultrasound. Although functional outcomes of focal therapies have been encouraging, with generally low rates of urinary incontinence and erectile dysfunction, robust medium- and long-term oncological outcomes are not available for all techniques. To date, major controversies in focal therapy concern appropriate patient selection, efficacy of focal therapies, as well as treatment paradigms based on the dominant index lesion hypothesis. This review articles discusses the current status of interventional therapies and the oncological and functional outcomes.