Diagnostic performance of a random versus lesion-directed biopsy of the prostate from transrectal ultrasound: results of a 5-year consecutive clinical study in 1 institution in South Taiwan

History of Urinary Retention Is a Risk Factor for Infection after Prostate Biopsy: A Nationwide, Population-Based Cohort Study

BACKGROUND AND AIM

Infection or bleeding after transrectal prostate biopsy remains a concern of both patients and urologists. We explored the risk of association of certain co-morbidities with both complications.

PATIENTS AND METHODS

Using the Taiwan National Health Insurance Research Database, we identified patients undergoing prostate biopsy from 2000 to 2013. We used logistic multivariable regression to search for associations between post-biopsy hospitalization and the two co-morbidities within a year after biopsy.

RESULTS

Among 3,601 prostate biopsies, 100 infections (3.77%) and 52 (1.44%) bleeding-related emergency room visits and hospitalizations were recorded within 30 days after biopsy. The group having the biopsy as an inpatient exhibited older age (p < 0.0001) and a higher percentage of having diabetes mellitus (p = 0.015) than patients without either complication. The logistic multivariable regression analysis showed that urinary retention, freedom from diabetes, and performance as an outpatient procedure were independent risk factors for infection-related hospitalization (odds ratios 1.81, 1.96, and 1.72; p values 0.031, 0.037, and 0.010, respectively).

CONCLUSION

Patients with a recent history of urinary retention have a higher probability of infection-related hospitalization after prostate biopsy.

Focal lesion at the midline of the prostate on transrectal ultrasonography: take it or leave it?

PURPOSE

The purpose of this study was to analyze the detection rate of prostate cancers from targeted biopsy specimens of midline focal lesions and to investigate the ultrasonographic findings to reduce unnecessary additional targeted biopsies.

METHODS

Ninety-eight men with midline focal lesions detected on transrectal ultrasonography were enrolled. Additional targeted biopsies for midline focal lesions were performed after 12-core random systematic biopsies. Correlations between the ultrasonographic characteristics of midline focal lesions and the pathologic results were analyzed.

RESULTS

Twenty of 98 targeted biopsy cores (20.4%) were positive for malignancy. In a univariate analysis, midline focal lesions without bulging contours (P=0.023), with involved margins (P=0.001), without hypoechoic perilesional rims (P=0.005), and with longer diameters (P=0.005) were statistically significant for cancer detection. In a multivariate analysis, involved margin (P=0.027), having longer diameter (P=0.011) or absence of hypoechoic perilesional rim (P=0.025) made a statistically significant contribution to cancer detection.

CONCLUSION

Biopsy of midline focal lesions was not always non-significant in the detection of prostate cancer. Additional targeted biopsies should be considered in cases of midline focal lesions with involved margins but without hypoechoic perilesional rims.

Triple Negative Breast Cancer: Nanosolutions for a Big Challenge

Triple negative breast cancer (TNBC) is a particular immunopathological subtype of breast cancer that lacks expression of estrogen and progesterone receptors (ER/PR) and amplification of the human epidermal growth factor receptor 2 (HER2) gene. Characterized by aggressive and metastatic phenotypes and high rates of relapse, TNBC is the only breast cancer subgroup still lacking effective therapeutic options, thus presenting the worst prognosis. The development of targeted therapies, as well as early diagnosis methods, is vital to ensure an adequate and timely therapeutic intervention in patients with TNBC. This review intends to discuss potentially emerging approaches for the diagnosis and treatment of TNBC patients, with a special focus on nano-based solutions that actively target these particular tumors.

Doppler spectral waveform parameters at neurovascular bundle vessels in patients with prostate biopsy

INTRODUCTION AND OBJECTIVES

There is a need to improve prescreening determination of prostate cancer to better select patients who need biopsy. Such a strategy properly implemented, will decrease the number of negative biopsies for prostate cancer and in turn better balance the risks and morbidity for patients recommended for biopsy. The aim of study is to investigate Doppler spectral waveform parameters of neurovascular bundle (NVB) vessels and determine differences between benign and malignant pathologies.

PATIENTS AND METHODS

We performed a prospective analysis involving 292 patients who received prostate biopsy for elevated prostate-specific antigen (PSA) values or abnormal digital rectal examination, as well as 174 patients with symptomatic benign prostatic hyperplasia. Doppler spectral waveform (DSW) parameters (peak-systolic velocity [PSV], end-diastolic velocity [EDV], and resistive index [RI]) were measured at bilateral NVB vessels through Doppler transrectal ultrasound at the right lateral decubitus position, compared, and analyzed among patients with benign versus malignant histology for each side.

RESULTS

Overall, both PSV and EDV at malignant sides were significantly higher than those at benign sides, as well as lower RI (all p-values <0.05, unpaired t-test). In subgroup analysis with 93 patients of serum PSA between 10 and 20 ng/mL and 56 patients with one-side malignancy, higher EDV and lower RI were significantly associated with malignancies (all p<0.05). The values of PSV and EDV rather than RI might be influenced by the patients' position and RI by the prostate volume.

CONCLUSIONS

In this study, DSW parameters (mainly EDV and RI) at NVB vessels were significantly associated with prostate cancer, particularly in patients with serum PSA of 10-20 ng/mL. It should be in caution that the patients' position and prostate volume may influence the Doppler signal as demonstrated in the current study. These findings can provide more diagnostic information before prostate biopsy.

Febrile infection in post-prostate biopsy: results of a ten-year single-institution study in South Taiwan

BACKGROUND

Post-biopsy infection is one of the major concerns of urologists and patients for prostate biopsy. Many efforts have been made to reduce the infection rate. We conducted a study at a single institution with the goal of describing the bacteriology and incidence trends of febrile infections following trans-rectal ultrasound (TRUS)-guided biopsy of the prostate.

MATERIALS AND METHODS

From January 1998 to December 2002 (Period 1 of the study), January 2003 to August 2005 (Period 2), September 2005 to October 2007 (Period 3), and November 2007 to December 2009 (Period 4), 1,406 patients underwent prostate biopsy at our hospital. All biopsies were conducted under TRUS guidance without preparation by enemas. Several steps were taken to reduce infectious complications following biopsy, including a shift to levofloxacin prophylaxis starting from Period 3 of our study and thorough instructions in post-biopsy self-care starting from the beginning of Period 4. The incidence and bacteriology of urinary tract infection (UTI) following the prostate biopsies were reviewed from chart records.

RESULTS

Twenty-eight of 514 (5.4%), 13 of 276 (4.7%) nine of 274 (3.2%), and three of 342 (0.9%) patients had post-biopsy febrile infections during the four periods of the study, respectively. Fifteen of 28 (53.5%), four of 13 (30.8%), five of nine (55.6%), and zero of three patients, respectively, had positive cultures of blood, urine, or both during the four study periods. Escherichia coli was the pathogen isolated most commonly and ampicillin- and fluoroquinolone-resistant strains of this organism were identified at a high frequency. The times to onset of fever after biopsy in the four study periods were 1.5±1.3 d, 3.7±2.7 d, 2.2±1.6 d, and 2.5±0.9 d, respectively.

CONCLUSIONS

Ampicillin- and fluoroquinolone-resistant strains of E. coli were the uropathogenic bacteria identified most commonly after prostate biopsy at our hospital. The incidence of UTI following prostate biopsy can be reduced by explaining instructions for medication and self-care thoroughly to patients undergoing such biopsy.

Acoustic radiation force impulse imaging of human prostates: initial in vivo demonstration

Reliably detecting prostate cancer (PCa) has been a challenge for current imaging modalities. Acoustic radiation force impulse (ARFI) imaging is an elasticity imaging method that uses remotely generated, focused acoustic beams to probe tissue stiffness. A previous study on excised human prostates demonstrated ARFI images portray various prostatic structures and has the potential to guide prostate needle biopsy with improved sampling accuracy. The goal of this study is to demonstrate the feasibility of ARFI imaging to portray internal structures and PCa in the human prostate in vivo. Custom ARFI imaging sequences were designed and implemented using a modified Siemens Antares™ scanner with a three-dimensional (3-D) wobbler, end-firing, trans-cavity transducer, EV9F4. Nineteen patients were consented and imaged immediately preceding surgical prostatectomy. Pathologies and anatomic structures were identified in histologic slides by a pathologist blinded to ARFI data and were then registered with structures found in ARFI images. The results demonstrated that when PCa is visible, it generally appears as bilaterally asymmetric stiff structures; benign prostatic hyperplasia (BPH) appears heterogeneous with a nodular texture; the verumontanum and ejaculatory ducts appears softer compared with surrounding tissue, which form a unique 'V' shape; and the boundary of the transitional zone (TZ) forms a stiff rim separating the TZ from the peripheral zone (PZ). These characteristic appearances of prostatic structures are consistent with those found in our previous study of prostate ARFI imaging on excised human prostates. Compared with the matched B-mode images, ARFI images, in general, portray prostate structures with higher contrast. With the end-firing transducer used for this study, ARFI depth penetration was limited to 22 mm. Image contrast and resolution were decreased as compared with the previous ex vivo study due to the small transducer aperture. Even with these limitations, this study suggests ARFI imaging holds promise for guidance of targeted prostate needle biopsy and focal therapy, as well as aiding assessment of changes during watchful waiting/active surveillance.

Prostate-specific antigen/solvent interaction analysis: a preliminary evaluation of a new assay concept for detecting prostate cancer using urinary samples

OBJECTIVE

To provide preliminary clinical performance evaluation of a novel prostate cancer (CaP) assay, prostate-specific antigen/solvent interaction analysis (PSA/SIA) that focused on changes to the structure of PSA.

METHODS

Two-hundred twenty-two men undergoing prostate biopsy for accepted clinical criteria at 3 sites (University Hospitals Case Medical Center in Cleveland, Cleveland Clinic, and Veterans Administration Boston Healthcare System) were enrolled in institutional review board-approved study. Before transrectal ultrasound-guided biopsy, patients received digital rectal examination with systematic prostate massage followed by collection of urine. The PSA/SIA assay determined the relative partitioning of heterogeneous PSA isoform populations in urine between 2 aqueous phases. A structural index, K, whose numerical value is defined as the ratio of the concentration of all PSA isoforms, was determined by total PSA enzyme-linked immunosorbent assay and used to set a diagnostic threshold for CaP. Performance was assessed using receiver operating characteristic (ROC) analysis with biopsy as the gold standard.

RESULTS

Biopsies were pathologically classified as case (malignant, n=100) or control (benign, n=122). ROC performance demonstrated area under the curve=0.90 for PSA/SIA and 0.58 for serum total PSA. At a cutoff value of k=1.73, PSA/SIA displayed sensitivity=100%, specificity=80.3%, positive predictive value=80.6%, and negative predictive value=100%. No attempt was made in this preliminary study to further control patient population or selection criteria for biopsy, nor did we analytically investigate the type of structural differences in PSA that led to changes in k value.

CONCLUSION

PSA/SIA provides ratiometric information independently of PSA concentration. In this preliminary study, analysis of the overall structurally heterogeneous PSA isoform population using the SIA assay showed promising results to be further evaluated in future studies.

Characterizing stiffness of human prostates using acoustic radiation force

Acoustic Radiation Force Impulse (ARFI) imaging has been previously reported to portray normal anatomic structures and pathologies in ex vivo human prostates with good contrast and resolution. These findings were based on comparison with histological slides and McNeal's zonal anatomy. In ARFI images, the central zone (CZ) appears darker (smaller displacement) than other anatomic zones and prostate cancer (PCa) is darker than normal tissue in the peripheral zone (PZ). Since displacement amplitudes in ARFI images are determined by both the underlying tissue stiffness and the amplitude of acoustic radiation force that varies with acoustic attenuation, one question that arises is how the relative displacements in prostate ARFI images are related to the underlying prostatic tissue stiffness. In linear, isotropic elastic materials and in tissues that are relatively uniform in acoustic attenuation (e.g., liver), relative displacement in ARFI images has been shown to be correlated with underlying tissue stiffness. However, the prostate is known to be heterogeneous. Variations in acoustic attenuation of prostatic structures could confound the interpretation of ARFI images due to the associated variations in the applied acoustic radiation force. Therefore, in this study, co-registered three-dimensional (3D) ARFI datasets and quantitative shear wave elasticity imaging (SWEI) datasets were acquired in freshly-excised human prostates to investigate the relationship between displacement amplitudes in ARFI prostate images and the matched reconstructed shear moduli. The lateral time-to-peak (LTTP) algorithm was applied to the SWEI data to compute the shear-wave speed and reconstruct the shear moduli. Five types of prostatic tissue (PZ, CZ, transition zone (TZ) and benign prostatic hyperplasia (BPH), PCa and atrophy) were identified, whose shear moduli were quantified to be 4.1 +/- 0.8 kPa, 9.9 +/- 0.9 kPa, 4.8 +/- 0.6 kPa, 10.0 +/- 1.0 kPa and 8.0 kPa, respectively. Linear regression was performed to compare ARFI displacement amplitudes and the inverse of the corresponding reconstructed shear moduli at multiple depths. The results indicate an inverse relation between ARFI displacement amplitude and reconstructed shear modulus at all depths. These findings support the conclusion that ARFI prostate images portray underlying tissue stiffness variations.

Diagnostic value of finger-guided prostate nodule biopsy combined with systemic random biopsy

BACKGROUND/PURPOSE

The purpose of this study was to compare prostate cancer detection rates and pathology results, using the Gleason grading system, of 12-core systemic random transrectal ultrasound-guided prostate biopsy (SB) and 3-core finger-guided prostate nodule biopsy (FGNB).

METHODS

Between January 2002 and December 2006, 148 patients with digitally palpable prostate nodules received SB and additional FGNB. The prostate cancer detection rates and Gleason scores of positive cancer specimens were compared between SB and combination biopsy (SB + FGNB). The patients' characteristics, including age, prostate specific antigen (PSA), percentage of free PSA and prostate volume were also recorded.

RESULTS

With simple SB, FGNB, and combination biopsy, the prostate cancer detection rates were 39.9%, 37.9%, and 44.6%, respectively. Of the 66 patients with prostate cancer, the Gleason sum was underestimated in three patients with simple SB only and in one patient with FGNB only. The false-negative rates for SB and FGNB were 10.6% and 15.2%, respectively.

CONCLUSION

In patients with a palpable prostate nodule, combination biopsy with systemic and nodule biopsy could avoid some misdiagnoses of prostate cancer and provide more accurate information for pathology grading.