Anterior distribution of Stage T1c nonpalpable tumors in radical prostatectomy specimens

Quantifying the Impact of Cancer on the Viscoelastic Properties of the Prostate Gland using a Quasi-Linear Viscoelastic Model

Pathological disorders can alter the mechanical properties of biological tissues, and studying such changes can help to better understand the disease progression. The prostate gland is no exception, as previous studies have shown that cancer can affect its mechanical properties. However, most of these studies have focused on the elastic properties of the tissue and have overlooked the impact of cancer on its viscous response. To address this gap, we used a quasi-linear viscoelastic model to investigate the impact of cancer on both the elastic and viscous characteristics of the prostate gland. By comparing the viscoelastic properties of segments influenced by cancer and those unaffected by cancer in 49 fresh prostates, removed within two hours after prostatectomy surgery, we were able to determine the influence of cancer grade and tumor volume on the tissue. Our findings suggest that tumor volume significantly affects both the elastic modulus and viscosity of the prostate (p-value less than 2%). Specifically, we showed that cancer increases Young's modulus and shear relaxation modulus by 20%. These results have implications for using mechanical properties of the prostate as a potential biomarker for cancer. However, developing an in vivo apparatus to measure these properties remains a challenge that needs to be addressed in future research. STATEMENT OF SIGNIFICANCE: This study is the first to explore how cancer impacts the mechanical properties of prostate tissues using a quasi-linear viscoelastic model. We examined 49 fresh prostate samples collected immediately after surgery and correlated their properties with cancer presence identified in pathology reports. Our results demonstrate a 20% change in the viscoelastic properties of the prostate due to cancer. We initially validated our approach using tissue-mimicking phantoms and then applied it to differentiate between cancerous and normal prostate tissues. These findings offer potential for early cancer detection by assessing these properties. However, conducting these tests in vivo remains a challenge for future research.

Role of preoperative magnetic resonance imaging on the surgical outcomes of radical prostatectomy: Does preoperative tumor recognition reduce the positive surgical margin in a specific location? Experience from a Thailand prostate cancer specialized center

Objective

Multiparametric magnetic resonance imaging (MRI) has become the standard of care for the diagnosis of prostate cancer patients. This study aimed to evaluate the influence of preoperative MRI on the positive surgical margin (PSM) rates.

Methods

We retrospectively reviewed 1070 prostate cancer patients treated with radical prostatectomy (RP) at Siriraj Hospital between January 2013 and September 2019. PSM rates were compared between those with and without preoperative MRI. PSM locations were analyzed.

Results

In total, 322 (30.1%) patients underwent MRI before RP. PSM most frequently occurred at the apex (33.2%), followed by posterior (13.5%), bladder neck (12.7%), anterior (10.7%), posterolateral (9.9%), and lateral (2.3%) positions. In preoperative MRI, PSM was significantly lowered at the posterior surface (9.0% vs. 15.4%, p=0.01) and in the subgroup of urologists with less than 100 RP experiences (32% vs. 51%, odds ratio=0.51, p<0.05). Blood loss was also significantly decreased when a preoperative image was obtained (200 mL vs. 250 mL, p=0.02). Multivariate analysis revealed that only preoperative MRI status was associated with overall PSM and PSM at the prostatic apex. Neither the surgical approach, the neurovascular bundle sparing technique, nor the perioperative blood loss was associated with PSM.

Conclusion

MRI is associated with less overall PSM, PSM at apex, and blood loss during RP. Additionally, preoperative MRI has shown promise in lowering the PSM rate among urologists who are in the early stages of performing RP.

MRI-informed prostate biopsy: What the radiologist should know on quality in biopsy planning and biopsy acquisition

Quality is currently recognized as the pre-requisite for delivering the clinical benefits expected by magnetic resonance imaging (MRI)-informed prostate biopsy (MRI-i-PB) in patients with a suspicion for clinically significant prostate cancer (csPCa). The "quality chain" underlying MRI-i-PB is multidisciplinary in nature, and depends on several factors related to the patient, imaging technique, image interpretation and biopsy procedure. This review aims at making the radiologist aware of biopsy-related factors impacting on MRI-i-PB quality, both in terms of biopsy planning (threshold for biopsy decisions, association with systematic biopsy and number of targeted cores) and biopsy acquisition (biopsy route, targeting technique, and operator's experience). While there is still space for improvement and better standardization of several biopsy-related procedures, current evidence suggests that high-quality MRI-i-PB can be delivered by acquiring and increased the number of biopsy cores targeted to suspicious imaging findings and perilesional area ("focal saturation biopsy"). On the other hand, uncertainty still exists as to whether software-assisted fusion of MRI and transrectal ultrasound images can outperform cognitive fusion strategy. The role for operator's experience and quality assurance/quality control procedures are also discussed.

Long-Term Results of a Phase 3 Randomized Prospective Trial of Erectile Tissue-Sparing Intensity-Modulated Radiation Therapy for Men With Clinically Localized Prostate Cancer

PURPOSE

The objective of this study was to determine whether limiting the doses delivered to the penile bulb (PB) and corporal bodies with intensity modulated radiation therapy (IMRT) preserves erectile function compared with standard IMRT in men with prostate cancer.

METHODS AND MATERIALS

A total of 117 patients with low- to intermediate-risk, clinical T1a-T2c prostate adenocarcinoma were enrolled in a single-institution, prospective, single-blind, phase 3 randomized trial. All received definitive IMRT to 74 to 80 Gy in 37 to 40 fractions and standard IMRT (s-IMRT) or erectile tissue-sparing IMRT (ETS-IMRT), which placed additional planning constraints that limited the D90 to the penile bulb and corporal bodies to ≤15 Gy and ≤7 Gy, respectively. Erectile potency was assessed with components of the International Index of Erectile Function and phosphodiesterase type 5 inhibitor (PDE5) medication records.

RESULTS

Sixty-two patients received ETS-IMRT, and 54 received s-IMRT; 1 patient did not receive radiation therapy. Before treatment, all patients reported erectile potency. No patients received androgen deprivation therapy. In the intention-to-treat analysis, treatment arms did not differ in potency preservation at 24 months (37.1% ETS-IMRT vs 31.5% s-IMRT, P = .53). Of 85 evaluable patients with International Index of Erectile Function and PDE5 medication follow-up, erectile potency was seen in 47.9% of patients in the ETS-IMRT arm and 46.0% of patients in the s-IMRT arm (P = .86). PDE5 inhibitors were initiated in 41.7% of ETS-IMRT patients and 35.1% of s-IMRT patients (P = .54). Among all patients enrolled, there was no difference in freedom from biochemical failure between those treated with ETS-IMRT and s-IMRT (5-year 91.8% vs 90.7%, respectively, P = .77), with a median follow-up of 7.4 years. There were no differences in acute or late gastrointestinal or genitourinary toxicity. An unplanned per-protocol analysis demonstrated no differences in potency preservation or secondary endpoints between patients who exceeded erectile tissue-sparing constraints and those who met constraints, although power was limited by attrition and unplanned dosimetric crossover.

CONCLUSIONS

ETS-IMRT that strictly limits dose to the penile bulb and corporal bodies is safe and feasible. Use of this planning technique did not show an effect on potency preservation outcomes at 2 years, though power to detect a difference was limited.

Landmarks in the evolution of prostate biopsy

Approaches and techniques used for diagnostic prostate biopsy have undergone considerable evolution over the past few decades: from the original finger-guided techniques to the latest MRI-directed strategies, from aspiration cytology to tissue core sampling, and from transrectal to transperineal approaches. In particular, increased adoption of transperineal biopsy approaches have led to reduced infectious complications and improved antibiotic stewardship. Furthermore, as image fusion has become integral, these novel techniques could be incorporated into prostate biopsy methods in the future, enabling 3D-ultrasonography fusion reconstruction, molecular targeting based on PET imaging and autonomous robotic-assisted biopsy.

Comparison of malignancy and spatial distribution between latent and clinical prostate cancer: an 8-year biopsy study

Background

Current prostate cancer (PCa) screening may detect nonprogressive lesion, leading to overdiagnosis and overtreatment. The purpose of the present study is to investigate whether the tumor pathological origin of latent prostate cancer (lPCa) and clinical prostate cancer (cPCa) are consistent, and to verify the current clinically significant prostate cancer criteria.

Methods

Prostate specimens were obtained from postmortem autopsy between 2014 and 2021 and patients who went through radical prostatectomy from 2013 to 2021. The pathological characteristics and spatial distribution of the lPCa group and cPCa group were compared and analyzed through SPSS software with P < 0.05 representing statistical significant.

Results

In lPCa group, a total of 45 tumor lesions from 24 lPCa cases were included, 54.2% of lPCa patients were ISUP ≥ 2, 12.5% had tumor volume ≥ 0.5 ml, and 16.7% had extraprostatic extension (EPE). In cPCa group, there were a total of 429 tumor lesions in 126 cases, 92.1% of cPCa patients were ISUP ≥ 2, and 82.5% had tumor volume of ≥ 0.5 ml. 36.3% had EPE. LPCa and cPCa have the same spatial distribution characteristics, and no significant difference was detected between the anterior and posterior zone. Peripheral zone tumors were significantly more common than transitional zone tumors. Tumors in apical 1/3 and middle 1/3 were significantly more common than basal 1/3.

Conclusion

The malignancy of cPCa is significantly higher than that of lPCa, and the spatial distribution of cPCa and lPCa is consistent. ISUP grade 2 is not sufficient to determine clinical significance of tumor.

Global Trends of Latent Prostate Cancer in Autopsy Studies

Simple Summary

The incidence of prostate cancer (PC) is statistically biased due to the increase in prostate-specific antigen (PSA) screening and the accuracy of national cancer registration systems. However, studies on latent PC provide less biased information. This comprehensive review included studies evaluating latent PC in several countries. The prevalence of latent PC has been stable since 1950 in Western countries, but it has increased over time in Asian countries. Latent PC in Asian men has increased in prevalence and is higher in grade. This increase occurred not only due to the increase in PSA screening, but also due to increasing adoption of a Westernized lifestyle. Racial differences between Caucasian and Asian men may also explain the tumor location of latent PC. The autopsy findings in patients with latent PC included a significant proportion of high grade and stage cancers, suggesting a need to reconsider the definition of clinically insignificant PC.

Abstract

The incidence of prostate cancer (PC) has been increasing in Asian countries, where it was previously low. Although the adoption of a Westernized lifestyle is a possible explanation, the incidence is statistically biased due to the increase in prostate-specific antigen (PSA) screening and the accuracy of national cancer registration systems. Studies on latent PC provide less biased information. This review included studies evaluating latent PC in several countries after excluding studies using random or single-section evaluations and those that did not mention section thickness. The findings showed that latent PC prevalence has been stable since 1950 in Western countries, but has increased over time in Asian countries. Latent PC in Asian men has increased in both prevalence and number of high-grade cases. Racial differences between Caucasian and Asian men may explain the tumor location of latent PC. In conclusion, the recent increase in latent PC in Asian men is consistent with an increase in clinical PC. Evidence suggests that this increase is caused not only by the increase in PSA screening, but also by the adoption of a more Westernized lifestyle. Autopsy findings suggest the need to reconsider the definition of clinically insignificant PC.

Power Doppler Sonography (PDS) and Modified TRUS Systematic Biopsies - Can this Combination Adequately Replace Multiparametric Prostate Magnetic Resonance Imaging (mp-MRI) in Candidates for Re Biopsies Who cannot Undergo mp-MRI

The MRI targeted biopsy (MRI-TBx) may increase the detection rate of clinically significant cancer (csPCa) in candidates for re-biopsy. However, there will be several patients in whom MRI is contraindicated. In this retrospective study we assessed the ability of combination of PDS guided biopsies (PDS-TBx) and modified SBx to substitute MRI-TBx. 154 men with persistently elevated PSA were referred for re-biopsy. Our protocol included a combination of MRI-TBx, DPS-TBx and modified SBx with additional biopsies from anterior lateral horns and anterior aspects of apex. MRI findings were defined as suspicious lesions (MRI-SL) and highly suspicious lesions (MRI-HL), based on PIRADS scale. In 40 patients csPCa was detected. While, MRI diagnosed csPCa in 36 patients (23%, n-36/154): 25% and 92% of biopsies targeted to the MRI- SL and MRI-HSL confirmed csPCa. Thirty-eight PDS hypervascular areas were found, while csPCa was diagnosed in 84% of these lesions, or in 28 patients (18%, n-28/154). SBx detected csPCa in 34 cores or in 21 patients (13%, n - 21/154). SBx missed cancers in the in the anterior aspect of middle gland. Combination of PDS-TBx + SBx detected csPCa in 35 (88% of csPCa) patients. Strongest predictors for the csPCa presence were MRI-HSL, PDS' lesions and biopsies from anterior aspect that included apex, mid gland and anterior lateral horns (p < 0.001 and p-0.008, respectively). The combination of PDS-TBx + SBx may miss 15% of csPCa detected by MRI. However, it can detect additional 10% of csPCa that were missed by MRI. To improve the accuracy of this combination, the anterior aspect of middle gland should be also included in the modified SBx. These changes in combination can make it helpful in candidates for re-biopsy who cannot undergo MRI.

Impact of extended prostate biopsy including apical anterior region for cancer detection and prediction of surgical margin status for radical prostatectomy

Objectives

We investigated diagnostic yield of initial biopsy and repeated biopsy including apical cores.

Methods

We investigated 573 consecutive men with PSA of ≤20 ng/ml who underwent prostate biopsy between 2004 and 2013. The initial 14-core biopsy consisted of the sextant type, lateral sites at the base and middle, lateral apices (la) at anterior horn sites, and apical anterior sites (aa). The repeated 18-core biopsy consisted of the initial 14-core biopsy with four transition zone (TZ) sites at the base (tzb) and middle (tzm).

Results

Prostate cancer was diagnosed in 178 (38.9%) of 458 men with the initial 14-core biopsy, and 44 (38.3%) of 115 men with the repeated 18-core biopsy. In the initial biopsy setting, the unique cancer detection rate was high in apical sites (apex, la, and aa: 6.2%, 6.2% and 5.1%, respectively). In the repeated setting, it was high in the TZ site in addition to the apical site (apex, la, aa, tzm, and tzb: 6.8%, 6.8%, 11.4%, 9.1% and 11.4%, respectively). The positive SM rate at the apex was higher in patients whose cancer was detected only in sites other than the sextant region than for those in the sextant region (36.4% vs. 14.8%, P = 0.037).

Conclusions

The initial 14-core and the repeated 18-core biopsy scheme including apical anterior cores are feasible for prostate cancer detection. We propose that apical biopsy cores can be used to predict not only the existence of cancer but also surgical margin status at the apex.

The detection and upgrade rates of prostate adenocarcinoma following transperineal template-guided prostate biopsy - a tertiary referral centre experience

INTRODUCTION

We aim to present transperineal template-guided prostate biopsy (template biopsy) outcomes at a tertiary referral centre. Furthermore, to identify the detection rate of prostate cancer in those with a previous negative transrectal ultrasound guided prostate biopsy and the upgrade rate of those on active surveillance for Gleason 3 + 3 = 6 prostate adenocarcinoma.

MATERIAL AND METHODS

We conducted a prospective study of 200 consecutive men who underwent template biopsy over a 22-month period in a tertiary referral centre, using a standard 24 region template prostate biopsy technique. Indications and histology results, as well as complications, were recorded.

RESULTS

Median age was 67 years and median PSA was 10 ng/mL. Overall detection rate was 47%. 39.5% of cases with previous negative transrectal biopsies were found to have prostate adenocarcinoma. 47.5% of cases on active surveillance for Gleason 3 + 3 = 6 prostate adenocarcinoma were upgraded. The most frequent complication was acute urinary retention at a rate of 12.5%, however, the use of a single prophylactic dose of tamsulosin was found to be beneficial, with 13 cases needed to treat to prevent one episode.

CONCLUSIONS

Template biopsies are safe and efficacious with an overall detection rate of 47% in the present series. Due to the high detection rate, one must consider template biopsy following one negative transrectal biopsy where there is persistent clinical suspicion. Furthermore, those considering active surveillance for Gleason 3 + 3 = 6 disease should be offered template biopsy to confirm the grade of their disease.

Should the involvement of skeletal muscle by prostatic adenocarcinoma be reported on biopsies?

Skeletal muscle is seen at the distal part of the prostate apex, where benign glands may reside as part of normal anatomy and histology, and extends more proximally anteriorly. At times, prostatic adenocarcinoma can be seen admixed with skeletal muscle, raising the question of extraprostatic extension. Although there has been increased attention regarding biopsy sampling of the distal apex to guide the performing of the apical dissection on radical prostatectomy, the finding of skeletal muscle involvement by prostatic adenocarcinoma has not been consistently reported by pathologists on biopsies. We searched our database spanning 12 years from 2000 to 2012 for all patients who had prostatic adenocarcinoma Gleason score 3 + 3 = 6 involving skeletal muscle on biopsy. We identified 220 patients who met the criteria. Of the 220 patients, 101 underwent prostatectomy, which comprised the "study group." Prostatectomy reports from these patients were compared with those of a "control group," which consisted of 201 contemporaneous patients with Gleason score 3 + 3 = 6 prostatic adenocarcinoma on biopsy without skeletal muscle involvement. The results showed a significantly higher percentage of positive margins in the study group compared with the control group (P = .006). The study group also had a higher percentage of positive margins at the apex admixed with skeletal muscle (P = .008). In summary, the findings in this study support that pathologists should report the involvement of skeletal muscle by tumor, and recommend that urologists performing radical prostatectomies on these patients try to ensure adequate excision in the apical area to avoid positive apical margin.

Long-term outcomes of nonpalpable prostate cancer (T1c) patients treated with radical prostatectomy

PURPOSE

Various strategies have been used to treat patients with nonpalpable prostate cancer (T1c). As one of the treatments for this stage, a radical prostatectomy was performed and the outcomes were evaluated.

METHODS

Between 1993 and 2002, 117 patients with T1c received a radical prostatectomy and their follow-up were examined by the end of 2013. Patients were classified according to risk groups using prostate-specific antigen (PSA) and Gleasson score, and outcomes of respective groups were compared.

RESULTS

Approximately 60% of patients were in low risk group, and the remaining patients were grouped into the intermediate or high risks in half. In 22% insignificant cancer was detected. Biochemical failure occurred in 14%. One patient exhibited bone metastasis, but no deaths from prostate cancer ware observed. The five and ten year overall survival rates were 92% and 75%, respectively, and the biochemical failure-free survival rates were 92% and 89%, respectively. No different outcomes were observed for the different risk groups in the overall and biochemical failure-free survival rates. T1c tumors contain a certain range of various stages of tumors, but most patients experienced favorable outcomes.

CONCLUSION

Radical prostatectomy as monotherapy is one of the treatment option for T1c prostate cancer patients, who have a long life span and belong to intermediate or high risk groups.

Analysis of prostate cancer localization toward improved diagnostic accuracy of transperineal prostate biopsy

PURPOSE

Delineating the precise localization of prostate cancer is important in improving the diagnostic accuracy of prostate biopsy.

METHODS

In Juntendo University Nerima Hospital, initial 12-core or repeat 16-core biopsies were performed using a transrectal ultrasound guided transperineal prostate biopsy method. We step-sectioned prostates from radical prostatectomy specimens at 5-mm intervals from the urethra to the urinary bladder and designated five regions: the (1) Apex, (2) Apex-Mid, (3) Mid, (4) Mid-Base, and (5) Base. We then mapped prostate cancer localization on eight zones around the urethra for each of those regions.

RESULTS

Prostate cancer was detected in 93 cases of 121 cases (76.9%) in the Apex, in 115 cases (95.0%) in the Apex-Mid, in 101 cases (83.5%) in the Mid, in 71 cases (58.7%) in the Mid-Base, and in 23 cases (19.0%) in the Base. In 99.2% of all cases, prostate cancers were detected from the Apex to Mid regions. For this reason, transperineal prostate biopsies have routinely been prioritized in the Apex, Apex-Mid, and Mid regions, while the Base region of the prostate was considered to be of lesser importance. Our analyses of prostate cancer localization revealed a higher rate of cancer in the posterior portion of the Apex, antero-medial and postero-medial portion of the Apex-Mid and antero-medial and postero-lateral portion of the Mid. The transperineal prostate biopsies in our institute performed had a sensitivity of 70.9%, a specificity of 96.6%, a positive predictive value (PPV) of 92.2% and a negative predictive value (NPV) of 85.5%.

CONCLUSIONS

The concordance of prostate cancer between prostatectomy specimens and biopsies is comparatively favorable. According to our study, the diagnostic accuracy of transperineal prostate biopsy can be improved in our institute by including the anterior portion of the Apex-Mid and Mid regions in the 12-core biopsy or 16-core biopsy, such that a 4-core biopsy of the anterior portion is included.

Low risk patients benefit from extreme anterior apical sampling on initial biopsy for prostate cancer diagnosis

BACKGROUND

To assess the effect of additional extreme apical sampling on prostate cancer (PCa) detection and aggressiveness in patients with standard risk versus high risk of a positive biopsy.

METHODS

Three thousand fifty three men were reviewed from our institution review board approved prostate biopsy database. Two thousand five hundred and twenty one underwent biopsy with 12 cores while 532 underwent 14 core sampling (2 extra cores from the extreme anterior apex). Patients were stratified into one of two risk groups: (1) standard risk of PCa (elevated prostate specific antigen (PSA) < 10 ng/ml, normal digital rectal exam (DRE), and no lesions on transrectal ultrasound (TRUS)), and (2) higher risk of PCa (PSA > 10 ng/ml and/or abnormal DRE and/or lesion on TRUS). Prostate cancer detection and disease characteristics were compared between the biopsy schemes stratified by risk of a positive biopsy.

RESULTS

PCa detection with 14 core sampling was more likely in all patients (OR 1.339, 95% CL 1.070-1.676) and in men with standard risk (OR 1.334, 95% CL 1.007-1.769). A greater median number of positive cores (3 vs. 2) and a higher maximum cancer % per core (40% vs. 25%) were seen in the 14 core cohort when stratified to standard risk. Gleason ≥7 was more likely detected with 14 cores in the standard risk group (55.6% vs. 45.2%). Differences in PCa detection and Gleason ≥7 between biopsy techniques were not noted in the higher risk group.

CONCLUSION

Extreme apical sampling increases aggressive cancer detection on initial biopsy, especially in patients with standard risk of PCa.

Management of an increasing prostate-specific antigen level after negative prostate biopsy

Patients who have a previously negative biopsy in the setting of clinical suspicion of prostate cancer still have a high risk of harboring significant undiagnosed disease. Various markers such as prostate-specific antigen (PSA) velocity, PSA density, PCA3, and newer markers may aid in repeat biopsy selection. Repeating the same biopsy procedure in such patients does not yield high cancer detection rates. More anteriorly directed transrectal or transperineal biopsies are indicated. Multiparametric magnetic resonance imaging can detect abnormal areas, and lesion-targeted biopsies can improve the cancer detection rate.

Transperineal biopsy of the prostate--is this the future?

Transperineal prostate biopsy is re-emerging after decades of being an underused alternative to transrectal biopsy guided by transrectal ultrasonography (TRUS). Factors driving this change include possible improved cancer detection rates, improved sampling of the anteroapical regions of the prostate, a reduced risk of false negative results and a reduced risk of underestimating disease volume and grade. The increasing incidence of antimicrobial resistance and patients with diabetes mellitus who are at high risk of sepsis also favours transperineal biopsy as a sterile alternative to standard TRUS-guided biopsy. Factors limiting its use include increased time, training and financial constraints as well as the need for high-grade anaesthesia. Furthermore, the necessary equipment for transperineal biopsy is not widely available. However, the expansion of transperineal biopsy has been propagated by the increase in multiparametric MRI-guided biopsies, which often use the transperineal approach. Used with MRI imaging, transperineal biopsy has led to improvements in cancer detection rates, more-accurate grading of cancer severity and reduced risk of diagnosing clinically insignificant disease. Targeted biopsy under MRI guidance can reduce the number of cores required, reducing the risk of complications from needle biopsy.

Improving prostate brachytherapy quality assurance with MRI-CT fusion-based sector analysis in a phase II prospective trial of men with intermediate-risk prostate cancer

PURPOSE

We combined sector analysis with MRI-CT fusion to comprehensively assess postimplant dosimetry after prostate brachytherapy.

METHODS AND MATERIALS

Subjects were 50 men with intermediate-risk prostate cancer treated with (125)I brachytherapy in a prospective phase II clinical trial. On Day 30 after the implantation, dosimetry was evaluated in the prostate base, midgland, and apex regions on fused MRI-CT scans and CT scans. Volumes of each sector receiving 100% of the prescribed dose (V100) and doses to 90% of each sector (D90) were also calculated on the ultrasonogram used for treatment planning and compared with values derived from CT and fused MRI-CT scans.

RESULTS

Fused MRI-CT scans revealed lower-than-expected doses for the whole prostate (V100=91.3%, D90=152.9Gy) compared with CT scans (98.5% and 183.6Gy, p<0.0001) and lower doses to the prostate base (V100=79%, D90=130Gy) vs. CT (96% and 170Gy, p<0.0001). However, lower doses to the prostate base did not adversely affect biochemical outcomes in men with biopsy-proven disease at the base. At a median followup time of 42 months, the mean prostate-specific antigen level for all patients was 0.3ng/mL, and no patient had experienced biochemical or clinical progression or recurrence.

CONCLUSIONS

MRI-CT fusion-based sector analysis was feasible and revealed significantly lower doses to the prostate base than doses estimated from CT alone, although this did not affect biochemical outcomes. MRI-CT fusion-based sector analysis may be useful for developing MRI-based dosimetric markers to predict disease outcomes and treatment-related morbidity.

The dosimetric impact of supplementing pre-planned prostate implants with discretionary 125I seeds

Introduction

Prostate implants at the British Columbia Cancer Agency are performed using a pre-planned technique. Physicians can augment the dose distribution using one to five non-planned ‘extra’ seeds and this option is determined without intraoperative feedback. The purpose of this research is to quantify the dosimetric impact of extra seeds and to assess the circumstances under which they are considered necessary.

Materials and methods

Implanting physicians used a questionnaire to record the three-dimensional location and their rationale for using extra seeds. A plan reconstruction algorithm was used to distinguish the extra seeds from the planned seeds. Distributions with and without extra seeds were calculated to quantify the dosimetric impact to the prostate, urethra and rectum.

Results

Extra seeds resulted in mean relative increases to V100, V150 and V200 of 3·7%, 13% and 19·1%, respectively. Mean prostate D90 increased from 147 to 156 Gy. Improvements in post-implant quality assurance codes were recorded in 30% of the implants with minimal dose increase to the rectum and urethra. Extra seeds were mainly deposited in the prostate anterior–superior quadrant.

Conclusions

The use of two to five extra seeds can result in improvements to pre-planned prostate implants, whereas the costs in terms of increased rectal and prostatic urethral dose are relatively minor.

Does Periprostatic Block Increase the Transrectal Ultrasound (TRUS) Biopsy Sepsis Rate in Men with Elevated PSA?

Introduction: Periprostatic nerve block (PPNB) is a common local anaesthetic technique in transrectal ultrasound-guided (TRUS) prostate biopsy, but concerns remain over the increased theoretical risks of urinary tract infection (UTI) and sepsis from the additional transrectal needle punctures. This study reviewed our biopsy data to assess this risk. Materials and Methods: Retrospective data collected from 177 men who underwent TRUS biopsy between July 2007 and December 2009 in a single institution were analysed. PPNB was administered using 1% xylocaine at the prostatic base and apex and repeated on the contralateral side under ultrasound guidance. Complications, including UTI sepsis, bleeding per rectum and acute retention of urine (ARU) were noted. Every patient was tracked for the first 2 weeks for complications until his clinic review. Demographic profile, biopsy parameters and histological findings were reviewed. Univariate and multivariate analysis of possible risk factors for development of sepsis after TRUS biopsy were performed. Statistical analysis was performed using SPSS 17.0. Results: Ninety (51%) men received PPNB and 87 (49%) did not. The groups were matched in age (PPNB: mean 62.7 ± 5.8 years; without PPNB: mean 64.4 ± 5.7 years) and prebiopsy prostate specific antigen (PSA) levels (PPNB: mean 8.2 ± 3.9 ng/mL; without PPNB: mean 8.3 ± 3.7 ng/mL). The PPNB group had a larger prostate volume, with more cores taken (P <0.05). On univariate and multivariate analysis controlling for age, PSA, prostate volume, number of cores taken and histological prostatitis, PPNB was not a significant risk factor for sepsis. Sepsis rates were 5.6% in the PPNB group and 5.7% in the other group (P = 0.956). Overall prostate cancer detection rate was 33.3%. Conclusion: The risk of sepsis was not increased in patients who received PPNB, even though this group had larger gland volumes and more biopsy cores taken. Key words: Periprostatic nerve block (PPNB), Sepsis, Transrectal ultrasound-guided (TRUS) prostate biopsy

Analysis of preoperative detection for apex prostate cancer by transrectal biopsy

Background. The aim of this study was to determine concordance rates for prostatectomy specimens and transrectal needle biopsy samples in various areas of the prostate in order to assess diagnostic accuracy of the transrectal biopsy approach, especially for presurgical detection of cancer in the prostatic apex. Materials and Methods. From 2006 to 2011, 158 patients whose radical prostatectomy specimens had been evaluated were retrospectively enrolled in this study. Concordance rates for histopathology results of prostatectomy specimens and needle biopsy samples were evaluated in 8 prostatic sections (apex, middle, base, and transitional zones bilaterally) from 73 patients diagnosed at this institution, besides factors for detecting apex cancer in total 118 true positive and false negative apex cancers. Results. Prostate cancer was found most frequently (85%) in the apex of all patients. Of 584 histopathology sections, 153 (49%) from all areas were false negatives, as were 45% of apex biopsy samples. No readily available preoperative factors for detecting apex cancer were identified. Conclusions. In Japanese patients, the most frequent location of prostate cancer is in the apex. There is a high false negative rate for transrectal biopsy samples. To improve the detection rate, transperitoneal biopsy or more accurate imaging technology is needed.

Temporal changes in the pathologic assessment of prostate cancer

Thirty years have witnessed dramatic changes in the manner in which we diagnose and manage prostate cancer. With prostate-specific antigen screening, there was a shift towards smaller, clinically localized tumors. Tumors are often multifocal and display phenotypic and molecular heterogeneity. Pathologic evaluation of tissue obtained by needle biopsy remains the gold standard for the diagnosis and risk assessment of prostate cancer. Years of experience with grading, along with changes in the amount of biopsy tissue obtained and diagnostic tools available, have produced shifts in grading practices among genitourinary pathologists. Trends in Gleason grading and advances in pathological risk assessment are reviewed with particular emphasis on recent Gleason grading modifications of the International Society of Urologic Pathology. Efforts to maximize the amount of information from pathological specimens, whether it be morphometric, histochemical, or molecular, may improve predictive accuracy of prostate biopsies. New diagnostic techniques are needed to optimize management decisions.

Targeted biopsy based on ADC map in the detection and localization of prostate cancer: a feasibility study

Purpose

To investigate the feasibility of targeted biopsy based on an apparent diffusion coefficient (ADC) map in the detection and localization of prostate cancer.

Materials and Methods

This study included 288 consecutive patients with high or increasing serum prostate-specific antigen (PSA) levels who underwent prostatic magnetic resonance imaging (MRI) examination with an ADC map. Four core-targeted biopsies of low ADC lesions were performed under transrectal-ultrasound guidance with reference to ADC map. The positive predictive values (PPVs) of low ADC lesions were calculated and compared for the peripheral zone (PZ), transition zone (TZ), and anterior portion, respectively. Comparisons of ADC values and sizes between malignant and nonmalignant lesions were also performed.

Results

A total of 313 low ADC lesions were detected in 195 patients and sampled by targeted biopsies. The PPVs were 55.3% (95% confidence interval [CI]: 50–61) in total, 61.0% (95% CI: 53–69) for PZ, 50.6% (95% CI: 43–58) for TZ, and 90.9% (95% CI: 81–100) for the anterior portion. The most common nonmalignant pathology of low ADC lesions was hyperplasia, followed by chronic prostatitis. There were significant differences in ADC values and sizes between malignant and nonmalignant low ADC lesions.

Conclusion

Targeted biopsies could be capable of detecting cancers well wherever they may be in the prostate, although the PPVs varied depending on the location of low ADC lesions.

Imaging-guided prostate biopsy: conventional and emerging techniques

Transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations owing to the operator's inability in most cases to directly visualize and target prostate lesions. Magnetic resonance (MR) imaging of the prostate overcomes many of these limitations by directly depicting areas of abnormality and allowing targeted biopsies. Accuracy in the detection of prostate cancer is improved by the combined use of standard T2-weighted MR imaging and advanced MR imaging techniques such as diffusion-weighted imaging, dynamic contrast-enhanced imaging, and MR spectroscopy. Suspicious-appearing regions of the prostate seen on MR images can be targeted at real-time transrectal US-guided biopsy to improve the diagnostic yield. MR imaging also can be performed for real-time guidance of transrectal prostate biopsy. Studies among patients who underwent at least one transrectal US-guided biopsy with a negative result before undergoing an MR imaging-guided biopsy showed improved detection rates with MR imaging-guided biopsy in comparison with the detection rates achieved with a repeat transrectal US-guided biopsy; however, MR imaging-guided biopsy is a more time-consuming procedure. A technique known as fused MR imaging- and transrectal US-guided biopsy, which relies on the coregistration of previously acquired MR images with real-time transrectal US images acquired during the procedure, shows promise but is limited by deformation of the prostate; this limitation is the subject of ongoing investigation. Another technique that is currently under investigation, MR imaging-guided prostate biopsy with robotic assistance, may one day help improve the accuracy of biopsy needle placement.

Location and pathological characteristics of cancers in radical prostatectomy specimens identified by transperineal biopsy compared to transrectal biopsy

PURPOSE

Anterior tumors are estimated to constitute 20% of prostate cancers. Current data indicate that transperineal biopsy is more reliable than transrectal biopsy in identifying these tumors. If correct, this superior reliability should result in an increased proportion of anterior tumors identified by transperineal biopsy. We investigated this hypothesis with reference to prostatectomy specimens.

MATERIALS AND METHODS

Radical prostatectomy histopathology records were retrospectively examined. Patients were grouped based on primary transperineal or transrectal biopsy as the modality used to identify the initial cancer. After grouping, tumor location and size were recorded and, thus, the proportion of anterior tumors was determined.

RESULTS

A total of 1,132 (414 transperineal and 718 transrectal) prostatectomy specimens were examined. Overall mean tumor size (1.8 and 2.0 cm(3)), stage (pT2 63.3% and 61%) and significance (5.1% and 5.1%) for the transperineal and transrectal methods were similar. However, the transperineal method was associated with proportionally more anterior tumors (16.2% vs 12%, p = 0.046), and identified them at a smaller size (1.4 vs 2.1 cm(3), p = 0.03) and lower stage (extracapsular extension 13% vs 28%, p = 0.03) compared to the transrectal method. The pT3 positive surgical margin rate for anterior vs other tumors was 69% vs 34.9%, respectively.

CONCLUSIONS

Overall transrectal and transperineal biopsy identify cancers that are similar in size, stage and significance. However, transperineal biopsy detected proportionally more anterior tumors (16.2% vs 12%), and identified them at a smaller size (1.4 vs 2.1 cm(3)) and stage (extracapsular extension 13% vs 28%) compared to transrectal biopsy. Identifying anterior tumors early is important because the positive surgical margin rate for anterior pT3 lesions is significantly higher.

Prostate saturation biopsy following a first negative biopsy: state of the art

INTRODUCTION

Saturation prostate biopsy (SPBx) has been initially introduced to improve prostate cancer (PCa) detection rate (DR) in the repeat setting. Nevertheless, the optimal number and the most appropriate location of the cores, together with the timing to perform a second PBx and the eventual modification of the PBx protocols according to the different clinical situations, are matters of debate. The aim of this review is to perform a critical analysis of the literature about the actual role of SPBx in the repeat setting.

MATERIALS AND METHODS

We performed a systematic review of the literature since 1995 up to 2011. Electronic searches were limited to the English language, using the MEDLINE database. The key words 'saturation prostate biopsy' and 'repeated prostate biopsy' were used.

RESULTS

SPBx improves PCa DR if clinical suspicion persists after previous biopsy with negative findings and provides an accurate prediction of prostate tumor volume and grade, even if the issue about the number and locations of the cores is still a matter of debate.

CONCLUSIONS

At present, SPBx seems to be really necessary in men with persistent suspicion of PCa after negative initial biopsy and probably in patients with a multifocal high-grade prostatic intraepithelial neoplasia or atypical small acinar proliferation. In the remaining situations, adopting an individualized scheme is preferable.

Correlation between cancer location and oncological outcome after radical prostatectomy

OBJECTIVES

To examine the association between cancer location, resection margins and oncological outcome in patients undergoing radical prostatectomy.

METHODS

A total of 505 patients who underwent radical prostatectomy between 1993 and 2009 were included in this analysis. Cancer location, resection margins and pathological factors were assessed based on the 2010 General Rules for Clinical and Pathological Studies on Prostate Cancer. Biochemical recurrence was defined as prostate-specific antigen >0.2 ng/mL.

RESULTS

Positive resection margins were found in 38.4% of all cases, in 30.3% of pT2 cases and in 57.7% of pT3 cases. The cancer was distributed evenly among the apex-anterior, apex-posterior and middle lesions, which each accounted for approximately 30% of the whole lesion in the main tumor. A higher rate of positive resection margins (47.6%) was found in the apex-anterior lesions. In minor tumors, most cancer was located in the middle lesion and accounted for approximately 60% of the lesion. However, positive resection margins were detected significantly more frequently in the apex-anterior lesion of minor tumors. The 5-year and 10-year biochemical recurrence-free survival rates were 36.2% and 32.0%, respectively, in patients with a positive resection margin, and 82.7% and 77.4%, respectively, in those with a negative resection margin. Cancer location was an independent risk factor for biochemical recurrence and a positive resection margin. Recurrence-free survival was lower in pT2 cases with a positive resection margin compared with pT3 cases with a negative resection margin.

CONCLUSIONS

Cancer location and occurrence of positive resection margins can have negative effects on recurrence-free survival. Thus, it is of utmost importance to avoid positive resection margins during radical prostatectomy.

Sexual function and the use of medical devices or drugs to optimize potency after prostate brachytherapy

PURPOSE

Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center.

METHODS AND MATERIALS

Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile volume receiving 100% of the prescribed dose (V100) were calculated.

RESULTS

At baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p = 0.04) and age (p = 0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients older than 70 maintained optimal potency (p = 0.02). Diabetes was related to a decline in potency (p = 0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p < 0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested.

CONCLUSIONS

Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry.

The optimal rebiopsy prostatic scheme depends on patient clinical characteristics: results of a recursive partitioning analysis based on a 24-core systematic scheme

BACKGROUND

The most beneficial number and the location of prostate biopsies remain matters of debate, especially after an initial negative biopsy.

OBJECTIVE

To identify the optimal combination of sampling sites (number and location) to detect prostate cancer (PCa) in patients previously submitted to an initial negative prostatic biopsy.

DESIGN, SETTING, AND PARTICIPANTS

A transrectal ultrasound-guided systematic 24-core prostate biopsy (24PBx) was performed prospectively in 340 consecutive patients after a first negative biopsy (at least 12 cores).

MEASUREMENTS

We relied on a classification and regression tree analysis to identify three clinically different subgroups of patients at dissimilar risk of harboring PCa at second biopsy. Subsequently, we set the cancer-positive rate of the 24PBx at 100% and calculated PCa detection rates for 255 possible combinations of sampling sites. We selected the optimal biopsy scheme (defined as the combination of sampling sites that detected 95% of all the cancers with the minimal number of biopsy cores) for each patient subgroup.

RESULTS AND LIMITATIONS

After an initial negative biopsy, cancer was detected at rebiopsy in 95 men (27.9%). At a given number of cores, the cancer detection rates varied significantly according to the different combination of sites considered. Three different PCa risk groups were identified: (1) previous report of atypical small acinar proliferation of the prostate (ASAP), (2) no previous ASAP and ratio of free prostate-specific antigen (fPSA) to total PSA (%fPSA) ≤10%, and (3) no previous ASAP and %fPSA >10%. For patients with previous ASAP or patients with no previous ASAP and %fPSA ≤10%, two schemes with different combinations of 14 cores were most favorable. The optimal sampling in patients with no previous ASAP and %fPSA >10% was a scheme with a combination of 20 cores.

CONCLUSIONS

Both the number and the location of biopsy cores taken affect cancer detection rates in a repeated biopsy setting. We developed an internally validated flowchart to identify the most advantageous set of sampling sites according to patient characteristics.

Predictive factors of Gleason score upgrading in localized and locally advanced prostate cancer diagnosed by prostate biopsy

Purpose

The Gleason score (GS) is an important factor that is considered when making decisions about prostate cancer and its prognosis. However, upgrading of the GS can occur between transrectal ultrasonography (TRUS) biopsy and radical prostatectomy. This study analyzed the clinical factors predictive of upgrading of the GS after radical prostatectomy compared with that at the time of TRUS biopsy.

Materials and Methods

We analyzed the medical records of 107 patients who had undergone radical prostatectomy. Patients were divided into two groups. Group 1 consisted of patients in whom the GS was not upgraded, and group 2 consisted of patients in whom the GS was upgraded. Associations between preoperative clinical factors and upgrading of the GS were analyzed. Preoperative clinical factors included age, prostate-specific antigen (PSA), prostate volume, PSA density, GS of TRUS biopsy, maximum core percentage of cancer, percentage of positive cores, number of biopsies, location of positive core with maximum GS, high-grade prostatic intraepithelial neplasia (HGPIN), inflammation on biopsy, and clinical stage.

Results

Among 85 patients, 42 (49%) patients had an upgraded GS after operation. TRUS biopsy core number of 12 or fewer (p=0.029) and prostate volume of 36.5 ml or less (p<0.001) were associated with upgrading of the GS. Preoperative clinical factors associated with nonupgrading of the GS were the detection of positive cores with a maximum GS at the apex (p=0.002) or in a hypoechoic lesion (p=0.002) in TRUS.

Conclusions

If the positive cores with maximum GS are located at the apex or in a hypoechoic lesion in TRUS, we can expect that the GS will not be upgraded. In patients with the clinical predictive factors of a prostate volume of 36.5 ml or less and TRUS biopsy core number of less than 12, we can expect upgrading of the GS after radical prostatectomy, and more aggressive treatment may be needed.

Optimizing performance and interpretation of prostate biopsy: a critical analysis of the literature

CONTEXT

The number and location of biopsy cores and the interpretation of prostate biopsy in different clinical settings remain the subjects of continuing debate.

OBJECTIVE

Our aim was to review the current evidence regarding the performance and interpretation of initial, repeat, and saturation prostatic biopsy.

EVIDENCE ACQUISITION

A comprehensive Medline search was performed using the Medical Subject Heading search terms prostate biopsy, prostate cancer, detection, transrectal ultrasound (TRUS), nomogram, and diagnosis. Results were restricted to the English language, with preference given to those published within the last 3 yr.

EVIDENCE SYNTHESIS

At initial biopsy, a minimum of 10 but not >18 systematic cores are recommended, with 14-18 cores in glands ≥ 50 cm³. Biopsies should be directed laterally, and transition zone (TZ) cores are not recommended in the initial biopsy setting. Further biopsy sets, either as an extended repeat or as a saturation biopsy (≥ 20 cores) including the TZ, are warranted in young and fit men with a persistent suspicion of prostate cancer. An immediate repeat biopsy is not indicated for prior high-grade prostatic intraepithelial neoplasia diagnosis given an adequate extended initial biopsy. Conversely, biopsies with atypical glands that are suspicious but not diagnostic of cancer should be repeated within 3-6 mo. Overall recommendations for further biopsy sets (a third set or more) cannot be made. Transrectal ultrasound-guided systematic biopsies represent the standard-of-care method of prostate sampling. However, transperineal biopsies are an up-to-standard alternative.

CONCLUSIONS

The optimal prostatic biopsy regimen should be based on the individualized clinical setting of the patient and should follow the minimum standard requirements reported in this paper.

Real-time balloon inflation elastography for prostate cancer detection and initial evaluation of clinicopathologic analysis

OBJECTIVE

The use of elastography is limited for prostate cancer detection because of the difficulty in obtaining stable and reproducible images. To overcome these limitations, we developed a new technique called real-time balloon inflation elastography (RBIE); with RBIE, balloon inflation and deflation are used in place of manual compression. We present the accuracy and feasibility of the RBIE technique for detecting prostate cancer.

MATERIALS AND METHODS

The results of a pathologic analysis of 55 prostatectomy specimens were compared with elastographic moving images obtained at the time of biopsy of the prostate.

RESULTS

The RBIE technique generated stable and repeatable elastographic moving images. The percentage of images affected by artifact due to slippage in the compression plane was reduced to 1% using the RBIE method compared with 32% using the manual compression method. With regard to tumor location, elastographic moving images obtained using the RBIE technique were in complete agreement with clinicopathologic evaluation of tumor location in eight cases (15%), showed partial agreement in 43 cases (78%), and disagreed in four cases (7%). In three different regions of the prostate, 84% of anterior tumors, 85% of middle tumors, and 60% of posterior tumors were detected. The tumor detection rates by Gleason score were 60% in tumors with a Gleason score of 5 or 6, 73% in tumors with a Gleason score of 7, 72% in tumors with a Gleason score of 8, and 74% in tumors with a Gleason score of 9 or 10.

CONCLUSION

The RBIE method improved the quality of elastographic moving images compared with the manual compression method. High-grade tumors and tumors of impalpable regions of the prostate were more frequently detected using RBIE. We conclude that RBIE is a promising method with which to detect prostate cancer.

Anterior apical biopsy: is it useful for prostate cancer detection?

OBJECTIVES

To evaluate the utility of a 12-core prostate biopsy protocol including apical anterior peripheral zone (AAPZ) cores.

METHODS

Between February 2002 and October 2006, 10-core and 12-core initial transrectal prostate biopsies were performed on 164 and 549 men, respectively. Two AAPZ-directed biopsies were included in the 12-core biopsy. During the same period, 12-core repeat biopsies including six AAPZ sites were performed on 118 men.

RESULTS

Cancer was found in 66 cases (40.2%) in the 10-core biopsy group and in 252 (45.9%) in the 12-core biopsy group. In this latter group, 13 (5.2%) of the 252 men with positive biopsy had cancer exclusively in the AAPZ cores. When the cancer detection rate at initial biopsy in AAPZ alone was compared according to the digital rectal examination (DRE) findings, it was significantly higher in men with normal rather than abnormal DRE: 12/250 (3.4%) vs 1/185 (0.5%) (P < 0.01). In repeat 12-core biopsies, cancer was detected in 25 (21.2%) men and 9 of them (36.0%) had cancer exclusively in the AAPZ cores. The cancer detection rate from AAPZ sites was significantly higher in repeat biopsy than that in initial biopsy (P < 0.01).

CONCLUSIONS

Addition of the AAPZ site-directed biopsy had greater utility in men with normal DRE and particularly in patients with a prior negative biopsy.