MRI-Targeted versus Ultrasonography-Guided Biopsy for Suspected Prostate Cancer

A novel biopsy scheme for prostate cancer: targeted and regional systematic biopsy

PURPOSE

To explore a novel biopsy scheme for prostate cancer (PCa), and test the detection rate and pathological agreement of standard systematic (SB) + targeted (TB) biopsy and novel biopsy scheme.

METHODS

Positive needles were collected from 194 patients who underwent SB + TB (STB) followed by radical prostatectomy (RP). Our novel biopsy scheme, targeted and regional systematic biopsy (TrSB) was defined as TB + regional SB (4 SB-needles closest to the TB-needles). The McNemar test was utilized to compare the detection rate performance for clinical significant PCa (csPCa) and clinical insignificant PCa (ciPCa). Moreover, the accuracy, positive predictive value (PPV) and negative predictive value (NPV) were investigated. The agreement between the different biopsy schemes grade group (GG) and RP GG were assessed. The concordance between the biopsy and the RP GG was evaluated using weighted κ coefficient analyses.

RESULTS

In this study, the overall detection rate for csPCa was 83.5% (162 of 194) when SB and TB were combined. TrSB showed better NPV than TB (97.0% vs. 74.4%). Comparing to STB, the TB-detection rate of csPCa had a significant difference (p < 0.01), while TrSB showed no significant difference (p > 0.999). For ciPCa, the overall detection rate was 16.5% (32 of 194). TrSB showed better PPV (96.6% vs. 83.3%) and NPV (97.6% vs. 92.9%) than TB. Comparing to STB, the detection rate of both schemes showed no significant difference (p = 0.077 and p = 0.375). All three schemes GG showed poor agreement with RP GG (TB: 43.3%, TrSB: 46.4%, STB: 45.9%). Using weighted κ, all three schemes showed no difference (TB: 0.48, TrSB: 0.51, STB: 0.51). In our subgroup analysis (PI-RADS = 4/5, n = 154), all three schemes almost showed no difference (Weighted κ: TB-0.50, TrSB-0.51, STB-0.50).

CONCLUSION

Our novel biopsy scheme TrSB (TB + 4 closest SB needles) may reduce 8 cores of biopsy compared with STB (standard SB + TB), which also showed better csPCa detection rate than TB only, but the same as STB. The pathological agreement between three different biopsy schemes (TB/TrSB/STB) GG and RP GG showed no difference.

Optimized grade group for reporting prostate cancer grade in systematic and MRI-targeted biopsies

PURPOSE

To explore an optimized grade group (oGG) criterion from systematic biopsies (SB) and targeted biopsies (TB) and offer a better prediction of radical prostatectomy (RP) grade group (GG).

METHODS

Positive needles were collected from 146 patients who underwent SB + TB followed by RP. The grade was assigned for two different kinds of biopsies with five GG criteria: (1) global GG (gGG); (2) most common GG (most common GG from SB + TB, mGG); (3) highest GG (highest numerical GG from SB + TB, hGG); (4) largest volume/linear length cancer GG (defined as GG from the SB + TB with the largest length of cancer in a needle, lGG). These biopsy grades were compared (equivalence, upgrade, or downgrade) with the final grade of the RP lesion, using weighted κ coefficients; (5) Then the best agreement of the (2) (3) (4) grading scores from SB or TB was combined to introduce an oGG.

RESULTS

In this study, gGG showed generally poor agreement (47.2%) with RP GG (weighted κ: 0.43). Using the three criteria (mGG, hGG, and lGG) of SB, mGG had the best agreement (55.5%, weighted κ: 0.46), while hGG and lGG had a lower agreement (48.6% and 48.6%, weighted κ: 0.42 and 0.38). Using the three criteria (mGG, hGG and lGG) of TB: lGG had the best agreement (56.8%, weighted κ: 0.43), while mGG and hGG had lower agreement (50.0% and 49.3%, weighted κ: 0.40 and 0.40); Then oGG was generated (higher GG between mGG of SB and lGG of TB) and the agreement of oGG increased to 59.6% and weighted κ was 0.49. Additionally, oGG had a lower upgrade rate than gGG, while the downgrade rate remained unchanged.

CONCLUSIONS

oGG showed better agreement with RP GG than gGG. oGG had a lower upgrade rate than gGG, while downgrade rate remained unchanged.

Current state of prostate-specific membrane antigen PET/CT imaging-targeted biopsy techniques for detection of clinically significant prostate cancer

Clinically significant prostate cancer (csPCa) is the focus of clinical diagnosis and treatment of prostate cancer (PCa). The current standard for diagnosing csPCa in men at risk relies on a transrectal (and in some instances transperineal) ultrasound-guided biopsy (TRUS-GB) that is blind to the location of cancer, leading to false-negative csPCa diagnoses. Over the past decade, PSMA PET/CT imaging-targeted prostate biopsy (PSMA PET/CT-TB), which obtains tissue samples from a defined suspicious area, has emerged as a promising solution for improving csPCa detection. Its feasibility and higher csPCa diagnostic value have been reported by a few case reports and studies. The current manuscript will review this latest targeted prostate puncture technology, summarize the existing applications of PSMA PET/CT-TB, including technical considerations, and discuss the advantages and challenges of each technique.

Targeted Biopsy With Reduced Number of Cores: Optimal Sampling Scheme in Patients Undergoing Magnetic Resonance Imaging/Transrectal Ultrasound Fusion Prostate Biopsy

The 3 Tesla (3T) magnetic resonance imaging (MRI) combined ultrasound (TRUS) targeted biopsy plus 12-core systematic biopsy (TBx + 12-SBx) was considered a reliable method for prostate cancer (PCa) diagnosis. To find another optimal sampling scheme with fewer cores and the same efficiency as TBx + 12-SBx for prostate biopsy, 113 patients who underwent five different hypothetical sampling schemes were analyzed and compared with TBx + 12-SBx. The detection rates of targeted biopsy plus 6-core lateral systematic biopsy (TBx + lateral 6-SBx) for PCa and clinically significant prostate cancer (csPCa) (99.1% and 96.4%, respectively) were higher than other schemes, and the area under the receiver operating characteristic curve of TBx + lateral 6-SBx for PCa and csPCa (0.991 and 0.990, respectively) were also significantly higher than other sampling schemes except TBx plus 6-core ipsilateral systematic biopsy (TBx + ipsilateral 6-SBx). Additionally, TBx + lateral 6-SBx had the lowest missed diagnosis rate. Thus, the TBx + lateral 6-SBx may be the optimal scheme for patients undergoing MRI/TRUS fusion prostate biopsy.

68Ga-PSMA PET/CT Combined with PET/Ultrasound-Guided Prostate Biopsy Can Diagnose Clinically Significant Prostate Cancer in Men with Previous Negative Biopsy Results

The purpose of this study was to investigate the feasibility and diagnostic efficacy of ⁶⁸Ga-prostate-specific membrane antigen (PSMA) PET/CT combined with PET/ultrasound-guided biopsy in the diagnosis of prostate cancer (PCa). Methods: In total, 31 patients with a previously negative prostate biopsy but persistent elevated serum prostate-specific antigen (PSA) were imaged with a ⁶⁸Ga-PSMA PET/CT ligand before undergoing repeat prostate biopsy. On the basis of the proposed Prostate Cancer Molecular Imaging Standardized Evaluation criteria, ⁶⁸Ga-PSMA PET/CT results were interpreted as negative (molecular-imaging-for-PSMA expression score [miPSMA-ES] of 0-1) or positive (miPSMA-ES of 2-3). All patients underwent standard template systematic biopsy with up to 4 additional PET/ultrasound-guided biopsy cores. The sensitivity, specificity, positive and negative predictive values, and accuracy of ⁶⁸Ga-PSMA PET/CT were determined. In addition, the correlation between the miPSMA-ES and the detection rate of PCa was also analyzed. Univariate logistic regression models were established using ⁶⁸Ga-PSMA PET/CT semiquantitative analysis parameters to predict the outcome of repeat prostate biopsy. Results: The median age of patients was 65 y (range, 53-81 y), and the median PSA level was 18.0 ng/mL (range, 5.48-49.77 ng/mL). PCa was detected in 15 of 31 patients (48.4%), and 12 of 31 patients (38.7%) had clinically significant PCa (csPCa). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ⁶⁸Ga-PSMA PET/CT in the diagnosis of csPCa were 100.0%, 68.4%, 66.7%, 100.0%, and 80.6%, respectively. The detection rate of PCa increased with the increase in miPSMA-ES. The detection rates of csPCa in the miPSMA-ES 0-1, 2, and 3 groups were 0%, 54.5%, and 85.7%, respectively. Semiquantitative analysis of ⁶⁸Ga-PSMA PET/CT images showed that predictive models based on the SUV_max of prostate lesion, tumor-to-normal-prostate background SUV_max, and tumor-to-normal-liver background SUV_max could effectively predict csPCa; area under the curves were 0.930, 0.877, and 0.956, respectively. Conclusion: This study preliminarily confirmed that ⁶⁸Ga-PSMA PET/CT imaging, combined with PET/ultrasound-guided prostate biopsy, can effectively detect csPCa. Prebiopsy ⁶⁸Ga-PSMA PET/CT had predictive value for csPCa in the studied patient population.

Integration of PSMA-targeted PET imaging into the armamentarium for detecting clinically significant prostate cancer

PURPOSE OF REVIEW

To explore the current state of using prostate-specific membrane antigen (PSMA)-targeted PET imaging to aid in the diagnosis of clinically significant prostate cancer.

RECENT FINDINGS

Prostate-specific antigen screening remains controversial, as it is associated with the underdetection of clinically significant prostate cancer as well as the overdetection and subsequent overtreatment of clinically insignificant disease. A diagnostic test that can accurately assess the presence of clinically significant prostate cancer and avoid detection of low-risk tumors is needed. Multiparametric magnetic resonance imaging (mpMRI) can aid in the detection of clinically significant prostate cancer and can be used with fusion-based biopsy platforms to target biopsies to specific lesions. However, there are several limitations of mpMRI including a modest negative predictive value for high-grade cancer. PSMA-targeted PET imaging has shown promise as a noninvasive test to aid in the detection of clinically significant prostate cancer while providing anatomical information to guide targeted biopsies. PSMA-targeted PET in combination with mpMRI offers a higher degree of diagnostic accuracy for imaging localized prostate cancer than either modality alone.

SUMMARY

PSMA-targeted PET imaging can aid in the identification of men with clinically significant prostate cancer. Further research is needed to determine the full potential of PSMA-targeted imaging in both the detection and treatment of localized prostate cancer.