Candidate selection for quadrant-based focal ablation through a combination of diffusion-weighted magnetic resonance imaging and prostate biopsy

Focal brachytherapy for localized prostate cancer: 5.7-year clinical outcomes and a pair-matched study with radical prostatectomy

OBJECTIVES

To report experience with focal brachytherapy (FB) and compare its clinical outcomes with those of radical prostatectomy (RP) in localized prostate cancer.

METHODS

Fifty-one patients with low- to intermediate-risk prostate cancer underwent low-dose-rate FB. Survival rates free from biochemical failure (BF), additional treatment (AT) including re-FB, and whole-gland or systemic salvage therapy (ST) were calculated and oncological risk factors were investigated. Patient-reported outcomes on genitourinary function were also assessed. Using propensity scoring, 51 pair-matched RP patients were selected. Oncological control, urinary continence, and ejaculation status after FB and RP were compared.

RESULTS

During a median 5.7-year follow-up, BF, AT, and ST occurred in 12 (24%), 10 (20%), and 4 FB patients (8%), respectively. 6 of 10 AT patients were managed with re-FB alone. In the RP cohort, 3 patients (6%) underwent ST. 5-year BF-free survival rate after FB was 79%. Compared to 5-year ST-free survival rate of 94% after RP, ST-free and AT-free survival rates after FB were 93% (P = 0.813) and 87% (P = 0.049), respectively. Multivariate analyses of FB-treated patients showed that time to PSA nadir was negatively associated with BF and AT (hazard ratio 0.84 and 0.83, respectively, P <0.001 for each). The difference in oncological outcomes between low- and intermediate-risk categories was not significant. At 2 years after FB and RP, pad-free continence rates were 100% and 81%, respectively (P = 0.001). Ejaculation was preserved in 67% and 0% of patients who had been capable of ejaculation at baseline, respectively (P <0.001).

CONCLUSION

In low- to intermediate-risk prostate cancer, FB-treated patients achieved superior genitourinary function compared to pair-matched RP patients. The need for ST was not substantially different between the 2 treatment cohorts. Over half of patients requiring AT could be managed by re-focal treatment rather than whole-gland ST. Early PSA nadir may predict poor oncological control after FB.

Nonmetastatic castration-resistant prostate cancer treated with salvage focal brachytherapy after external beam radiotherapy

INTRODUCTION

The efficacy of salvage local therapy after external beam radiotherapy has recently gained attention. However, a challenge with these therapies is the risk of significant genitourinary and gastrointestinal toxicity. Focal brachytherapy may be a treatment option because of its potential to reduce side effects.

CASE PRESENTATION

A patient with castration-resistant prostate cancer was found to be free of metastases on whole-body magnetic resonance imaging following external beam radiotherapy, and prostate biopsy revealed a localized recurrence in the ventral prostate. The patient underwent salvage focal brachytherapy and had a prostate-specific antigen progression-free survival of 23 months. No adverse effects were observed following salvage brachytherapy.

CONCLUSION

Our case suggests that salvage focal brachytherapy may be an effective local treatment option for nonmetastatic castration-resistant prostate cancer that has relapsed after external beam radiotherapy, wherein the lesion is confined to a small area within the prostate.

Impact on genitourinary function and quality of life following focal irreversible electroporation of different prostate segments

PURPOSE

We aimed to evaluate the genitourinary function and quality of life (QoL) following the ablation of different prostate segments with irreversible electroporation (IRE) for localized prostate cancer (PCa).

METHODS

Sixty patients who received primary focal IRE for organ-confined PCa were recruited for this study. Patients were evaluated for genitourinary function and QoL per prostate segment treated (anterior vs. posterior, apex vs. base vs. apex-to-base, unilateral vs. bilateral). IRE system settings and patient characteristics were compared between patients with preserved vs. those with impaired erectile function and urinary continence. Data were prospectively collected at baseline, 3, 6, and 12 months using the expanded prostate cancer index composite, American Urological Association symptom score, SF-12 physical and mental component summary surveys. Difference over time within segments per questionnaire was evaluated using the Wilcoxon's signed rank test. Outcome differences between segments were assessed using covariance models. Baseline measurements included questionnaire scores, age, and prostate volume.

RESULTS

There were no statistically significant changes over time for overall urinary (P = 0.07-0.89), bowel (P = 0.06-0.79), physical (P = 0.18-0.71) and mental (P = 0.45-0.94) QoL scores within each segment. Deterioration of sexual function scores was observed at 6 months within each segment (P = 0.001-0.16). There were no statistically significant differences in QoL scores between prostate segments (P = 0.08-0.97). Older patients or those with poor baseline sexual function at time of treatment were associated with a greater risk of developing erectile dysfunction.

CONCLUSION

IRE is a feasible modality for all prostate segments without any significantly different effect on the QoL outcomes. Older patients and those with poor sexual function need to be counseled regarding the risk of erectile dysfunction.

Prediction of unilateral prostate cancer by the combination of transrectal ultrasonography-guided prostate biopsy and multi-parametric magnetic resonance imaging: A real-life experience

Hemi-ablation of prostate cancer (PCa) requires an accurate prediction of laterality. Recently, multi-parametric magnetic resonance imaging (mpMRI) has recently been increasingly used to enhance clinical staging and characterization of tumor foci. Thus, we tried to investigate the real-life accuracy of combinatory approach of using both transrectal ultrasound (TRUS)-guided prostatic biopsy and mpMRI in predicting the laterality of PCa. We reviewed the records of 335 men who were suspected of having unilateral PCa on multi (≥ 12)-core TRUS-guided biopsy and preoperative mpMRI and subsequently had undergone radical prostatectomy (RP) at our institution. Based on the analysis of pathologic outcomes from RP, the performance of the combinatory approach in predicting the pathological laterality of PCa was evaluated. Pathology was classified to be unfavorable when showing a Gleason pattern of 4/5 or pT3/N1 features. Significant cancer was defined as non-organ-confined disease, having a Gleason pattern of 4/5, or showing a cancer volume of ≥ 0.5 mL. Among the 335 unilateral lobes not suspected to harbor tumor from either the TRUS biopsy or mpMRI, the actual absence rate of malignancy was only 13.7% from a pathologic analysis of RP specimens. Even among the 115 D'Amico low-risk group, the absence rate of malignancy was only 26.1% in unilateral lobes not suspected to harbor tumor. Among the 335 lobes, unfavorable pathology and significant cancer were not observed in 36.1% and 30.7%, respectively. The absence rates of unfavorable pathology and significant cancer among the D'Amico low risk group were 56.5% and 47.8%, respectively. Meanwhile, the absence rate of dominant Gleason pattern 4 or 5 was 74.9% among the 335 total subjects. Our real-life clinical experience showed that the combination of multi-core TRUS-guided biopsy and mpMRI did not provide reliable accuracy in the prediction of true unilaterality of PCa.

Current status and progress of focal therapy in Asia

PURPOSE OF REVIEW

With the increasing incidence of low-to-intermediate risk of prostate cancer (PCa) by the introduction of prostate-specific antigen (PSA) screening, focal therapy has become one of the promising treatment options in the world. In Asia, same movement are occurring using several technologies including cryoablation, high-intensity focused ultrasound, brachytherapy and irreversible electroporation. However, these are still not common strategies to treat organ-confined PCa. The purpose of this review is to summarize the most updated experience and future direction of focal therapy in Asian countries.

RECENT FINDINGS

The prevalence and diagnosis of PCa are increasing in Asian countries. This increase is related to various factors including the widespread implementation of PSA testing and lifestyle changes to more Westernized diets. With the increasing detection rate of early stage PCa, overdetection and overtreatment are recognized even in Asia. In this setting, accumulating data on multiparametric MRI and MRI-targeted biopsy as well as MRI-transrectal ultrasound (TRUS) fusion biopsy suggest the potential in improving the detection of clinically significant PCa in Asia. Furthermore, targeted focal therapy has emerged as a promising treatment strategy aiming for both providing oncological outcome and maintaining functional preservation in many Asian countries.

SUMMARY

At present, focal therapy is not a current standard choice for the treatment of localized PCa in Asian countries. However, with the increase of localized PCa and patient's preference for less invasive treatment with preservation of organ-function, focal therapy should become a definite treatment option for localized PCa in Asia.

Patient selection for prostate focal therapy in the era of active surveillance: an International Delphi Consensus Project

BACKGROUND

Whole-gland extirpation or irradiation is considered the gold standard for curative oncological treatment for localized prostate cancer, but is often associated with sexual and urinary impairment that adversely affects quality of life. This has led to increased interest in developing therapies with effective cancer control but less morbidity. We aimed to provide details of physician consensus on patient selection for prostate focal therapy (FT) in the era of contemporary prostate cancer management.

METHODS

We undertook a four-stage Delphi consensus project among a panel of 47 international experts in prostate FT. Data on three main domains (role of biopsy/imaging, disease and patient factors) were collected in three iterative rounds of online questionnaires and feedback. Consensus was defined as agreement in ⩾80% of physicians. Finally, an in-person meeting was attended by a core group of 16 experts to review the data and formulate the consensus statement.

RESULTS

Consensus was obtained in 16 of 18 subdomains. Multiparametric magnetic resonance imaging (mpMRI) is a standard imaging tool for patient selection for FT. In the presence of an mpMRI-suspicious lesion, histological confirmation is necessary prior to FT. In addition, systematic biopsy remains necessary to assess mpMRI-negative areas. However, adequate criteria for systematic biopsy remains indeterminate. FT can be recommended in D'Amico low-/intermediate-risk cancer including Gleason 4+3. Gleason 3+4 cancer, where localized, discrete and of favorable size represents the ideal case for FT. Tumor foci <1.5 ml on mpMRI or <20% of the prostate are suitable for FT, or up to 3 ml or 25% if localized to one hemi-gland. Gleason 3+3 at one core 1mm is acceptable in the untreated area. Preservation of sexual function is an important goal, but lack of erectile function should not exclude a patient from FT.

CONCLUSIONS

This consensus provides a contemporary insight into expert opinion of patient selection for FT of clinically localized prostate cancer.

The expanding landscape of diffusion-weighted MRI in prostate cancer

The added value of diffusion-weighted magnetic resonance imaging (DW-MRI) for the detection, localization, and staging of primary prostate cancer has been extensively reported in original studies and meta-analyses. More recently, DW-MRI and related techniques have been used to noninvasively assess prostate cancer aggressiveness and estimate its biological behavior. The present article aims to summarize the potential applications of DW-MRI for noninvasive optimization of pretherapeutic risk assessment, patient management decisions, and evaluation of treatment response.