Transrectal doppler ultrasound during prostate biopsy: clinical utility and limitations

The Performance of Different Parametric Ultrasounds in Prostate Cancer Diagnosis: Correlation with Radical Prostatectomy Specimens

BACKGROUND

Prostate cancer is a prevalent cancer among men. Multiparametric ultrasound [mpUS] is a diagnostic instrument that uses various types of ultrasounds to diagnose it. This systematic review aims to evaluate the performance of different parametric ultrasounds in diagnosing prostate cancer by associating with radical prostatectomy specimens.

METHODOLOGY

A review was performed on various ultrasound parameters using five databases. Systematic review tools were utilized to eliminate duplicates and identify relevant results. Reviewers used the Quality Assessment of Diagnostic Accuracy Results [QUADAS-2] to evaluate the bias and applicability of the study outcomes.

RESULT

Between 2012 and 2023, eleven studies were conducted to evaluate the performance of the different ultrasound parametric procedures in detecting prostate cancer using grayscale TRUS, SWE, CEUS, and mpUS. The high sensitivity of these procedures was found at 55%, 88.6%, 81%, and 74%, respectively. The specificity of these procedures was found to be 93.4%, 97%, 88%, and 59%, respectively. This high sensitivity and specificity may be associated with the large lesion size. The studies revealed that the sensitivity of these procedures in diagnosing clinically significant prostate cancer was 55%, 73%, 70%, and 74%, respectively, while the specificity was 61%, 78.2%, 62%, and 59%, respectively.

CONCLUSIONS

The mpUS procedure provides high sensitivity and specificity in PCa detection, especially for clinically significant prostate cancer.

The role of multiparametric ultrasound in the detection of clinically significant prostate cancer

PURPOSE

Transrectal ultrasound (US) imaging is paramount to the successful completion of prostate biopsies. Certain US features have been associated with prostate cancer (PCa), but their utility remains controversial. We explored the role of multiparametric US (mpUS) in the detection of clinically significant PCa.

METHODS

We performed a retrospective cohort study to contrast the findings of prostate MRI and mpUS. Patients who underwent MRI, US and biopsy between 2015 and 2021 were included. Biopsies were performed using a systematic approach (12 cores), as well as with MRI (4 cores/lesion) and US (1 core/lesion) targeting. The US features analyzed consisted of: calcifications, hypoechoic lesions and power or color Doppler positivity. Gleason 3 + 4 or higher was used as to define true positives. Measures of diagnostic accuracy were calculated for the different imaging modalities.

RESULTS

The final cohort included 74 patients, of which 24 (32.4%) had clinically significant PCa. The concordance between MRI and US was 63.5%. Seven individuals with discordant results had clinically significant PCa. MRI alone was more sensitive (87.5% vs 75%) but less specific (28% vs 32%) than US alone. An all-inclusive approach considering any suspicious US or MRI finding had a sensitivity of 95.8%. A more restrictive approach, targeting lesions noted in both US and MRI, yielded the highest specificity (50.0%) and accuracy (55.4%).

CONCLUSION

Biopsy targeting based on US findings can provide additional diagnostic information that may increase sensitivity or specificity. Additional research into this topic could open the door to a more personalized approach to prostate biopsy.

Prostate Cancer Ultrasound: Is Still a Valid Tool?

Purpose of Review

The main purpose of this paper review is to highlight the latest ultrasound (US) imaging technologies of the prostate gland, an organ increasingly at the center of attention in the field of oncological diseases of the male sex, which needs a 360° evaluation in order to obtain tailored therapeutic planning. Specialist urological evaluation is designated for this purpose, together with integrated prostate imaging which currently tends to focus more and more on the use of US imaging and its state-of-the-art technologies in iconographic diagnosis, biopsy and, sometimes, treatment of prostatic cancer.

Recent Findings

In particular, the main tools to which reference is made, represent a valid aid to basic US technologies already widely known and diffused, like the grayscale US or the Doppler US, for a "multiparametric" evaluation of the prostate cancer. The concept of multiparametricity is explained by the integration of prostate imaging obtained both with the US evaluation of the gland before and after administration of contrast medium, with the elaboration of parametric maps of quantitative measurement of the enhancement, and with elastography that provides information about the tissue consistency, a finding that strongly relates with the degree of cellularity and with the tumor grading.

Summary

Prostate cancer screening consists of dosing serum levels of prostate-specific antigen (PSA) and performing digit-rectal examination (DRE), more or less associated with transrectal prostate ultrasound (TRUS). However, although these are the most common techniques in clinical practice, they have numerous limitations and make the diagnosis of prostate cancer often challenging. The purpose of mp-US is to enrich the clinical-laboratory data and, above all, the standard US imaging with further details to strengthen the suspicion of malignancy of a prostate tumor, which needs to be addressed to diagnostic deepening with biopsy. This review article provides a summary of the current evidence on mp-US imaging in the evaluation of a clinically significant prostate cancer, comparing the data obtained to the imaging of mp-MRI, the reference tool both in diagnosis and staging.

A Comparative Study of Prostate Cancer Detection Rate Between Transperineal COG-TB and Transperineal FUS-TB in Patients with PSA ≤20 ng/mL

Background: The combination of prebiopsy MRI and transperineal targeted biopsies is being increasingly used to obtain tissues from patients with suspected prostate cancer (PCa). Objective: To investigate the difference in PCa detection rate between transperineal cognitive fusion TB (COG-TB) and transperineal software fusion TB (FUS-TB). Participants: The present study included 163 male patients with suspected PCa who had not undergone prostate biopsy, had a prostate-specific antigen (PSA) level of ≤20 ng/mL, and had been examined by bi-parameter MRI and confirmed to have prostate nodules by prostate imaging reporting and data system version 2 (PI-RADS V2) scores ≥3 (from December 3, 2018 to October 7, 2019). Intervention: Seventy-one patients underwent transperineal COG-TB, and 92 patients underwent transperineal FUS-TB. The detection rate of the first four needles was compared. Results: No significant difference was found in the overall detection rate of PCa between COG-TB and FUS-TB (60.56% vs 51.08%, p = 0.228). This result was consistent even after stratifying by PI-RADS score. There was also no significant difference between COG-TB and FUS-TB in the detection rate of clinically significant PCa (p = 0.641). Moreover, COG-TB and FUS-TB showed no difference in the detection rate of PCa with different Gleason scores. Conclusions: In patients with suspected PCa with PSA ≤20 ng/mL and PI-RADS ≥3, FUS-TB was comparable to COG-TB in the detection rate of PCa.

Endorectal power Doppler/grayscale ultrasound-guided biopsies vs. multiparametric MRI/ultrasound fusion-guided biopsies in males with high risk of prostate cancer: A prospective cohort study

Multiparametric MRI fusion with transrectal ultrasound (mpMRI/TRUS)-guided biopsy has the sensitivity of mpMRI with the practicality of TRUS, but males with no cancerous lesion(s) detected on mpMRI have a considerable remaining risk of cancer. Endorectal power Doppler ultrasound improves the sensitivity of grayscale ultrasound-guided biopsies. The objective of the present study was to evaluate the beneficial effect of endorectal power Doppler/grayscale ultrasound-guided biopsy over that of mpMRI/TRUS-guided biopsy for decision-making regarding prostatectomy in males with a high risk of prostate cancer. Data regarding endorectal power Doppler/grayscale ultrasound-guided biopsies and mpMRI/TRUS-guided biopsies of 1,094 males with elevated specific prostate antigen, were included. Radical prostatectomy was performed in males aged <70 years with Gleason scores ≥3+4 in any one of the biopsy reports. The histopathological data of the surgical specimen of 776 males were included in the analysis. Compared to the histopathology of the surgical specimen, endorectal power Doppler/grayscale ultrasound-guided biopsies had a lower sensitivity (0.930 vs. 1.000; P<0.0001) but mpMRI/TRUS-guided biopsies had the same sensitivity (0.990 vs. 1.000; P=0.02). The accuracy of mpMRI/TRUS-guided biopsies was higher than that of endorectal power Doppler/grayscale ultrasound-guided biopsies (0.944 vs. 0.783). On mpMRI, lesions of 105 subjects (10%) with a Likert scale score of <3 were identified. Among them, 14 subjects (2%) had Gleason scores of ≥3+4 as determined by endorectal power Doppler/grayscale ultrasound-guided biopsies. In addition, 20 (2%) false-positive lesions compared to the histopathological analysis of the surgical specimen were identified from mpMRI/TRUS-guided biopsies. In conclusion, mpMRI/TRUS-guided biopsy was indicated to have a moderate performance and endorectal power Doppler/grayscale ultrasound-guided biopsy had a scant performance for decision-making regarding prostatectomy.

Evolution of prostate biopsy techniques. Looking back on a meaningful journey

BACKGROUND

The technique of prostate biopsy has evolved a long way since its inception to being a safe diagnostic procedure. The principles of the biopsy technique continue to improvise with the knowledge about prostate cancer and availability of newer treatment options like active surveillance and focal therapy. Currently, we depend on accurate cancer information from the biopsy more than ever for deciding the ideal treatment option.

AIM

The aim of this review is to present the major milestones in prostate biopsy technique evolutions and its impact on the prostate cancer management.

ACQUISITION OF EVIDENCE

We performed a detailed non-systematic literature review to present the historical facts on the transformations in prostate biopsy techniques and also the direction of present research to improve accurate cancer detection.

SUMMARY OF EVIDENCE

There is a clear change in trend in biopsy technique before and after the introduction of transrectal ultrasound and prostate specific antigen. In the earlier era, the biopsies were aimed at palpable nodules and obtaining adequate prostatic tissue for diagnosis while the later era has moved towards detection of non-palpable and early prostate cancer. Recently, there is an increasing trend towards image guided targeted biopsies to extract maximum cancer information from minimum biopsy cores.

CONCLUSION

Prostate biopsy techniques have seen major changes since its inception and have a major impact on prostate cancer management. There is a great potential for research which can further support the newer treatment options like focal therapy.

Low LKB1 Expression Results in Unfavorable Prognosis in Prostate Cancer Patients

Background

The present study aimed to compare the expression of liver kinase B1 (LKB1) in prostate cancer (PCa) tissues and the paired adjacent tissues, then to evaluate the statistical relationship between LKB1 expression and prognosis of PCa patients.

Material/Methods

The relative expression of LKB1 at mRNA level was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of LKB1 at protein level was measured by immunohistochemistry (IHC) method. The relationship between LKB1 expression and clinicopathologic characteristics was estimated by chi-square test. Kaplan-Meier method was used to analyze the overall survival of PCa patients with different LKB1 expression. Cox regression analysis was performed to estimate the significance of LKB1 expression and clinicopathologic characteristics in the prognosis of PCa patients.

Results

The relative expression of LKB1 at mRNA level was significantly lower in PCa tissues than in the normal tissues (P<0.001). The LKB1 expression was proved to be affected by clinical stage (P=0.019) and PSA concentration (P=0.031) of PCa patients. Moreover, patients with negative LKB1 expression had shorter survival than those with positive expression. Cox regression analysis confirmed that LKB1 could be regarded as a prognostic biomarker for PCa patients (P=0.001, HR=3.981, 95% CI=1.698–9.336).

Conclusions

The expression of LKB1 was lower in PCa tissues and might be a predictor for the prognosis of PCa patients.