Focal Therapy for Prostate Cancer: Getting Ready for Prime Time

The Transatlantic Recommendations for Prostate Gland Evaluation with Magnetic Resonance Imaging After Focal Therapy (TARGET): A Systematic Review and International Consensus Recommendations

BACKGROUND AND OBJECTIVE

Magnetic resonance imaging (MRI) can detect recurrences after focal therapy for prostate cancer but there is no robust guidance regarding its use. Our objective was to produce consensus recommendations on MRI acquisition, interpretation, and reporting after focal therapy.

METHODS

A systematic review was performed in July 2022 to develop consensus statements. A two-round consensus exercise was then performed, with a consensus meeting in January 2023, during which 329 statements were scored by 23 panellists from Europe and North America spanning urology, radiology, and pathology with experience across eight focal therapy modalities. Using RAND Corporation/University of California-Los Angeles methodology, the Transatlantic Recommendations for Prostate Gland Evaluation with MRI after Focal Therapy (TARGET) were based on consensus for statements scored with agreement or disagreement.

KEY FINDINGS AND LIMITATIONS

In total, 73 studies were included in the review. All 20 studies (100%) reporting suspicious imaging features cited focal contrast enhancement as suspicious for cancer recurrence. Of 31 studies reporting MRI assessment criteria, the Prostate Imaging-Reporting and Data System (PI-RADS) score was the scheme used most often (20 studies; 65%), followed by a 5-point Likert score (six studies; 19%). For the consensus exercise, consensus for statements scored with agreement or disagreement increased from 227 of 295 statements (76.9%) in round one to 270 of 329 statements (82.1%) in round two. Key recommendations include performing routine MRI at 12 mo using a multiparametric protocol compliant with PI-RADS version 2.1 standards. PI-RADS category scores for assessing recurrence within the ablation zone should be avoided. An alternative 5-point scoring system is presented that includes a major dynamic contrast enhancement (DCE) sequence and joint minor diffusion-weighted imaging and T2-weighted sequences. For the DCE sequence, focal nodular strong early enhancement was the most suspicious imaging finding. A structured minimum reporting data set and minimum reporting standards for studies detailing MRI data after focal therapy are presented.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The TARGET consensus recommendations may improve MRI acquisition, interpretation, and reporting after focal therapy for prostate cancer and provide minimum standards for study reporting.

PATIENT SUMMARY

Magnetic resonance imaging (MRI) scans can detect recurrent of prostate cancer after focal treatments, but there is a lack of guidance on MRI use for this purpose. We report new expert recommendations that may improve practice.

Gold nanoshells for prostate cancer treatment: evidence for deposition in abdominal organs

PURPOSE

Gold-silica nanoshell therapy [AuroShells with subsequent focal laser therapy (AuroLase)] is an emerging targeted treatment modality for prostate cancer. We reviewed pre- and post-treatment unenhanced CT imaging to assess for retained gold-silica nanoshells in the abdomen and pelvis.

METHODS

This single-institution retrospective study identified patients in the AuroLase pilot who underwent pre- and post-treatment unenhanced abdominopelvic CT. The attenuation, before and after gold-silica nanoshell administration, of the liver, spleen, pancreas, kidneys, prostate, blood pool, paraspinal musculature, and abnormal lymph nodes were manually measured by two readers. After inter-reader agreement was calculated using intraclass correlation (ICC), a permutation test was used to assess pre- and post-therapy attenuation differences.

RESULTS

Four patients met the inclusion criteria. Mean age was 72.3 ± 5.9 years. Median time interval between pre-treatment CT and treatment, and between treatment and post-treatment CT, was 232 days and 236.5 days, respectively. The two readers' attenuation measurements had very high agreement (ICC = 0.99, p < 0.001). The highest differences in organ attenuation between pre- and post-therapy scans were seen in all four patients in the liver and spleen (liver increased by an average of 28.9 HU, p = 0.010; spleen increased by an average of 63.7 HU, p = 0.012). A single measured lymph node increased by an average of 58.9 HU. In the remainder of the measured sites, the change in attenuation from pre- to post-therapy scans ranged from -0.1 to 3.8 HU (p > 0.05).

CONCLUSION

Increased attenuation of liver and spleen at CT can be an expected finding in patients who have received gold-silica nanoshell therapy.

A multi-center international study to evaluate the safety, functional and oncological outcomes of irreversible electroporation for the ablation of prostate cancer

BACKGROUND

Irreversible electroporation (IRE) is a novel technique to treat localized prostate cancer with the aim of achieving oncological control while reducing related side effects. We present the outcomes of localized prostate cancer treated with IRE from a multi-center prospective registry.

METHODS

Men with histologically confirmed prostate cancer were recruited to receive IRE. All the patients were proposed for prostate biopsy at 1-year post-IRE ablation. The functional outcomes were measured by the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF-5) questionnaires. The safety of IRE was graded by the treatment-related adverse events (AEs) according to the Common Terminology Criteria for Adverse Events (CTCAE).

RESULTS

411 patients were recruited in this study from July 2015 to April 2020. The median follow-up time was 24 months (IQR 15-36). 116 patients underwent repeat prostate biopsy during 12-18 months after IRE. Clinically significant prostate cancer (Gleason ≥ 3 + 4) was detected in 24.1% (28/116) of the patients; any grade prostate cancers were found in 59.5% (69/116) of the patients. The IPSS score increased significantly from 7.1 to 8.2 (p = 0.015) at 3 months but decreased to 6.1 at 6 months (p = 0.017). Afterwards, the IPSS level remained stable during follow-up. The IIEF-5 score decreased at 3 months from 16.0 to 12.1 (p < 0.001) and then maintained equable afterwards. The rate of AEs was 1.8% at 3 months and then dropped to less than 1% at 6 months and remained stable until 48 months after IRE. Major AEs (Grade 3 or above) were rare.

CONCLUSION

For men with localized prostate cancer, IRE could achieve good urinary and sexual function outcomes and a reasonable oncological result. The real-world data are consistent with earlier studies, including recently published randomized controlled studies. The long-term oncological results need further investigation and follow-up.

Outcomes of Salvage Robotic-assisted Radical Prostatectomy in the last decade: systematic review and perspectives of referral centers

PURPOSE

Salvage robotic-assisted radical prostatectomy (S-RARP) has gained prominence in recent years for treating patients with cancer recurrence following non-surgical treatments of Prostate Cancer. We conducted a systematic literature review to evaluate the role and outcomes of S-RARP over the past decade.

MATERIAL AND METHODS

A systematic review was conducted, encompassing articles published between January 1st, 2013, and June 1st, 2023, on S-RARP outcomes. Articles were screened according to PRISMA guidelines, resulting in 33 selected studies. Data were extracted, including patient demographics, operative times, complications, functional outcomes, and oncological outcomes.

RESULTS

Among 1,630 patients from 33 studies, radiotherapy was the most common primary treatment (42%). Operative times ranged from 110 to 303 minutes, with estimated blood loss between 50 to 745 mL. Intraoperative complications occurred in 0 to 9% of cases, while postoperative complications ranged from 0 to 90% (Clavien 1-5). Continence rates varied (from 0 to 100%), and potency rates ranged from 0 to 66.7%. Positive surgical margins were reported up to 65.6%, and biochemical recurrence ranged from 0 to 57%.

CONCLUSION

Salvage robotic-assisted radical prostatectomy in patients with cancer recurrence after previous prostate cancer treatment is safe and feasible. The literature is based on retrospective studies with inherent limitations describing low rates of intraoperative complications and small blood loss. However, potency and continence rates are largely reduced compared to the primary RARP series, despite the type of the primary treatment. Better-designed studies to assess the long-term outcomes and individually specify each primary therapy impact on the salvage treatment are still needed. Future articles should be more specific and provide more details regarding the previous therapies and S-RARP surgical techniques.

Patient-reported Satisfaction and Regret Following Focal Therapy for Prostate Cancer: A Prospective Multicenter Evaluation

Background

Several reports are available regarding the treatment decision regret of patients receiving conventional treatments for localized prostate cancer (PCa); yet data on patients undergoing focal therapy (FT) are sparse.

Objective

To evaluate the treatment decision satisfaction and regret among patients who underwent FT for PCa with high-intensity focused ultrasound (HIFU) or cryoablation (CRYO).

Design setting and participants

We identified consecutive patients who underwent HIFU or CRYO FT as the primary treatment for localized PCa at three US institutions. A survey with validated questionnaires, including the five-question Decision Regret Scale (DRS), International Prostate Symptom Score (IPSS), and International Index of Erectile Function (IIEF-5), was mailed to the patients. The regret score was calculated based on the five items of the DRS, and regret was defined as a DRS score of >25.

Outcome measurements and statistical analysis

Multivariable logistic regression models were applied to assess the predictors of treatment decision regret.

Results and limitations

Of 236 patients, 143 (61%) responded to the survey. Baseline characteristics were similar between responders and nonresponders. During a median (interquartile range) follow-up of 43 (26-68) mo, the treatment decision regret rate was 19.6%. On a multivariable analysis, higher prostate-specific antigen (PSA) at nadir after FT (odds ratio [OR] 1.48, 95% confidence interval [CI] 1.1-2, p = 0.009), presence of PCa on follow-up biopsy (OR 3.98, 95% CI 1.5-10.6, p = 0.006), higher post-FT IPSS (OR 1.18, 95% CI 1.01-1.37, p = 0.03), and newly diagnosed impotence (OR 6.67, 95% CI 1.57-27, p = 0.03) were independent predictors of treatment regret. The type of energy treatment (HIFU/CRYO) was not a predictor of regret/satisfaction. Limitations include retrospective abstraction.

Conclusions

FT for localized PCa is well accepted by the patients, with a low regret rate. Higher PSA at nadir, presence of cancer on follow-up biopsy, bothersome postoperative urinary symptoms, and impotence after FT were independent predictors of treatment decision regret.

Patient summary

In this report, we looked at the factors affecting satisfaction and regret in patients with prostate cancer undergoing focal therapy. We found that focal therapy is well accepted by the patients, while presence of cancer on follow-up biopsy as well as bothersome urinary symptoms and sexual dysfunction can predict treatment decision regret.

Effect of Focal vs Extended Irreversible Electroporation for the Ablation of Localized Low- or Intermediate-Risk Prostate Cancer on Early Oncological Control: A Randomized Clinical Trial

Importance

Focal ablative irreversible electroporation (IRE) is a therapy that treats only the area of the tumor with the aim of achieving oncological control while reducing treatment-related functional detriment.

Objective

To evaluate the effect of focal vs extended IRE on early oncological control for patients with localized low- and intermediate-risk prostate cancer.

Design, Setting, and Participants

In this randomized clinical trial conducted at 5 centers in Europe, men with localized low- to intermediate-risk prostate cancer were randomized to receive either focal or extended IRE ablation. Data were collected at baseline and at regular intervals after the procedure from June 2015 to January 2020, and data were analyzed from September 2021 to July 2022.

Main Outcomes and Measures

Oncological outcome as indicated by presence of clinically significant prostate cancer (International Society of Urological Pathology grade ≥2) on transperineal template-mapping prostate biopsy at 6 months after IRE. Descriptive measures of results from that biopsy included the number and location of positive cores.

Results

A total of 51 and 55 patients underwent focal and extended IRE, respectively. Median (IQR) age was 64 years (58-67) in the focal ablation group and 64 years (57-68) in the extended ablation group. Median (IQR) follow-up time was 30 months (24-48). Clinically significant prostate cancer was detected in 9 patients (18.8%) in the focal ablation group and 7 patients (13.2%) in the extended ablation group. There was no significant difference in presence of clinically significant prostate cancer between the 2 groups. In the focal ablation group, 17 patients (35.4%) had positive cores outside of the treated area, 3 patients (6.3%) had positive cores in the treated area, and 5 patients (10.4%) had positive cores both in and outside of the treated area. In the extended group, 10 patients (18.9%) had positive cores outside of the treated area, 9 patients (17.0%) had positive cores in the treated area, and 2 patients (3.8%) had positive cores both in and outside of the treated area. Clinically significant cancer was found in the treated area in 5 of 48 patients (10.4%) in the focal ablation group and 5 of 53 patients (9.4%) in the extended ablation group.

Conclusions and Relevance

This study found that focal and extended IRE ablation achieved similar oncological outcomes in men with localized low- or intermediate-risk prostate cancer. Because some patients with intermediate-risk prostate cancer are still candidates for active surveillance, focal therapy may be a promising option for those patients with a high risk of cancer progression.

Trial Registration

ClinicalTrials.gov Identifier: NCT01835977.

Focal therapy of localized prostate cancer

In the treatment of localized prostate cancer, controlling the cancer and maintaining quality of life are important. Focal therapy of localized prostate cancer aims to treat the lesion/part of the prostate that includes the index lesion, which determines the prognosis. We performed a non-systematic review of novel studies on focal therapy of localized prostate cancer as primary treatment published between 2016 and 2021. For mainly intermediate-risk patients, therapeutic technology, such as cryoablation, brachytherapy, high-intensity focused ultrasound, photodynamic therapy, microwave-coagulation, electroporation, and laser ablation, etc., were performed. These procedures are minimally invasive and safe, and provide good functional outcome: a 94-100% pad-free rate against urinary incontinence and 47-86% erectile function, which is sufficient for sexual intercourse. Accurate three-dimensional mapping of the targeted lesion could be an essential navigation technique for therapeutic success. Intermediate- to short-term oncological outcomes were good, resulting in downstaging of the patient's status to no clinically significant cancer; however, transition to conventional whole-gland treatment was necessary in about 10-30% of patients. It is important to select appropriate patients by both multiparametric magnetic resonance imaging and targeted biopsy, and to follow-up postoperatively with methods such as active surveillance. Clinically significant prostate-specific antigen reduction, image response using preoperative and postoperative multiparametric magnetic resonance imaging, and histological analysis should be combined for follow-up.

Focal Therapy for Prostate Cancer: The Impact on Sexual Function

Focal therapy (FT) has emerged as a potential treatment for localized prostate cancer (PCa) with encouraging functional outcomes. According to the compelling evidence based on meta-analyses and recent trials, erectile function (EF) is mostly retained at 6 and 12 months after FT when compared to baseline. These findings are consistent across different energy sources reported to date. However, overall, quality of life, including impotence, was not the endpoint for most studies. Additionally, impotency has not been consistently reported in most of the recent literature. Furthermore, confounding factors such as baseline potency and usage of phosphodiesterase 5 inhibitors (PDE5-I) were also frequently undisclosed. Long-term functional outcomes are awaited. To fully comprehend how FT affects EF, more extensive long-term randomized clinical trials using EF as a primary outcome are needed.