Salvage Radiotherapy After High-Intensity Focussed Ultrasound for Recurrent Localised Prostate Cancer

Salvage external beam radiotherapy after HIFU failure in localized prostate cancer: A single institution experience

Purpose/objectives

High-intensity focused ultrasound (HIFU) remains investigational as primary treatment for localized prostate cancer but is sometimes offered to select patients. At HIFU failure, data guiding salvage treatment is limited to small retrospective series with short follow-up. We evaluated our institutional experience using salvage radiation therapy (SRT) after HIFU failure.

Materials/methods

We conducted a retrospective analysis of patients with local failure post-HIFU who received salvage image-guided external beam radiation therapy (EBRT) delivered via intensity-modulated radiotherapy (IMRT). Our primary endpoint was biochemical failure-free survival (bFFS) defined as prostate-specific antigen (PSA) nadir + 2 ng/mL. Secondary endpoints included metastasis-free survival (MFS) and overall survival (OS). Endpoints were evaluated using Kaplan-Meier analysis.

Results

From 2013 to 2018, 12 out of 96 patients treated with primary HIFU received SRT via conventional or moderate hypofractionation. Median time from HIFU to SRT was 13.5 months. Seven patients had stage migration to high-risk disease at the time of SRT. Mean PSA prior to SRT was 8.2ug/L and mean nadir post-SRT was 1.2ug/L. Acute International Prostate Symptom Score (IPSS) as well as International Index of Erectile Dysfunction (IIEF) scores were similar to baseline (p = 0.5 and 0.1, respectively). Late toxicities were comparable to those reported after primary EBRT for localized prostate cancer. At a median follow-up of 46 months, the OS was 100%. The 5-year bFFS and MFS were both 83.3%.

Conclusions

To our knowledge, we report one of the largest series on contemporary SRT post HIFU failure. We show that SRT is feasible, effective and carries no additional acute or delayed toxicity.

Salvage Radiotherapy Plus Androgen Deprivation Therapy for High-Risk Prostate Cancer with Biochemical Failure after High-Intensity Focused Ultrasound as Primary Treatment

We conduct a retrospective analysis of salvage radiotherapy plus androgen deprivation therapy (SRT+ADT) for high-risk prostate cancer patients with biochemical failure after high-intensity focused ultrasound (HIFU) as the primary treatment. A total of 38 patients, who met the criteria of biochemical failure and were consecutively treated with SRT+ADT, were enrolled. All patients received intensity modulated radiotherapy with a median dose of 70 Gy to the clinical target volume. ADT was given before, during or after the course of SRT with the duration of ≦6 months (n = 14), 6−12 months (n = 12) or >12 months (n = 12). The median follow-up was 45.9 months. A total of 10 (26.3%) patients had biochemical failure after SRT+ADT. The cumulative 5-year biochemical progression free survival (b-PFS) and overall survival (OS) rate was 73.0% and 80.3%, respectively. A nadir prostate-specific antigen (nPSA) value 0.02 ng/mL was observed to predict the b-PFS in multivariate analysis. The 5-year b-PFS was 81.6% for those with nPSA < 0.02 compared with 25.0% with nPSA ≧ 0.02. The adverse effects related to SRT+ADT were mild in most cases and only three (8%) patients experienced grade 3 urinary toxicities. For high-risk prostate cancer after HIFU as primary treatment with biochemical failure, our study confirms the feasibility of SRT+ADT with high b-PFS, OS and low toxicity.

Comparing the toxicity and disease control rate of radiotherapy for prostate cancer between salvage settings after high-intensity focused ultrasound therapy and initial settings

The purpose of this retrospective study was to compare the toxicity and disease control rate of radiotherapy for prostate cancer in salvage settings after high-intensity focused ultrasound (HIFU) therapy (HIFU cohort) with those in radical settings (non-HIFU cohort). From 2012 to 2020, 215 patients were identified for this study and 17 were treated in the salvage settings after HIFU. The median follow-up time was 34.5 months (range: 7-102 months, inter-quartile range [IQR]: 16-64 months). Genitourinary (GU) and gastrointestinal (GI) adverse events were evaluated in acute and late periods with Common Terminology Criteria for Adverse Events version 5, and the rates of biochemical-clinical failure free survival (BCFS) and overall survival (OS) were estimated. The cumulative incidence of late GU Grade 2 or greater toxicity after five years was significantly different between the non-HIFU and HIFU cohorts with rates of 7.3% and 26.2%, respectively (P = 0.03). Regarding GI Grade 2 or greater toxicity, there was no significant difference between the two cohorts. The 5y-BCFS was 84.2% in the non-HIFU cohort and 69.5% in the HIFU cohort with no significant difference (P = 0.10) and the 5y-OS was 95.9% and 92.3%, respectively (P = 0.47). We concluded that the possibility of increased late GU Grade 2 or greater should be considered when applying salvage radiotherapy for local recurrence after HIFU.

Salvage radiotherapy following HiFU: An institutional series and literature review

INTRODUCTION

Algorithms for the treatment of prostate cancer (PrCa) rely on risk grouping, and those who fall into low (LR) and favourable intermediate risk (FIR) categories have multiple options for treatment. High-intensity focused ultrasound (HiFU) is a local treatment modality that uses ultrasound waves to ablate prostate cancer. In case of treatment failure, optimal salvage modality after HiFU remains unclear.

METHODS

Here, we describe a retrospective review of our regional cancer database for men who underwent salvage radiotherapy after failure of HiFU treatment for prostate cancer. Oncologic and toxicity outcomes of the men identified in our database are discussed.

RESULTS

We identified 14 men in our regional database who received salvage radiotherapy (70-74 Gy with or without androgen deprivation therapy (ADT) after primary HiFU, in the period of 2009-2017. No cases of any grade 3 or higher toxicity were observed. In our cohort, 50% (7/14) of patients developed secondary biochemical failure at a median follow-up of 54 months post-radiotherapy, with a mean time to biochemical failure of 39 months. We compare our data to other available reports to date consisting mostly of small, non-randomized studies. Our biochemical control rates are noticeably lower compared with those reported by other studies but our length of follow-up is longer, compared with other studies.

CONCLUSION

The available data to date suggest that salvage radiotherapy after HiFU failure is well-tolerated albeit with only modest efficacy.

The Use of High-Intensity Focused Ultrasound (HIFU) Plus 150mg Bicalutamide as First Line Salvage Therapy for Local Recurrent Prostate Cancer

Patients with localized prostate cancer (PCa) are often treated with radical prostatectomy (RP). However, more than 30% of such patients have high risk of recurrence. Salvage radiotherapy (SRT), androgen deprivation therapy (ADT) and combination of radiotherapy and ADT are the standard care for recurrent PCa. Recently, high intensity focused ultrasound (HIFU) has gradually applied in the treatment of recurrent PCa. Here, we proposed a hypothesis that combined HIFU and bicalutamide 150mg as first line salvage therapy to treat patients with local recurrent PCa with visible lesions due to the following advantages: (1) HIFU is effective in reducing local tumor load, and bicalutamide 150mg is a feasible and safety option to combine with HIFU. (2) Compared with radiotherapy, HIFU plus 150mg bicalutamide is minimal invasiveness with fewer adverse effects and better quality of life(QOL); (3) Radiotherapy can be preserved as the second-line salvage method in the cases who are failure to HIFU and 150mg bicalutamide combination. More clinical trials are warranted to confirm this hypothesis in treatment with recurrent PCa.

Comparative Effectiveness Analyses of Salvage Prostatectomy and Salvage Radiotherapy Outcomes Following Focal or Whole-Gland Ablative Therapy (High-Intensity Focused Ultrasound, Cryotherapy or Electroporation) for Localised Prostate Cancer

AIMS

Ablative therapy, such as focal therapy, cryotherapy or electroporation, aims to treat clinically significant prostate cancer with reduced treatment-related toxicity. Up to a third of patients may require further local salvage treatment after ablative therapy failure. Limited descriptive, but no comparative, evidence exists between different salvage treatment outcomes. The aim of this study was to compare oncological and functional outcomes after salvage robot-assisted radical prostatectomy (SRARP) and salvage radiotherapy (SRT).

MATERIALS AND METHODS

Data were collected prospectively and retrospectively on 100 consecutive SRARP cases and 100 consecutive SRT cases after ablative therapy failure in a high-volume tertiary centre.

RESULTS

High-risk patients were over-represented in the SRARP group (66.0%) compared with the SRT group (48.0%) (P = 0.013). The median (interquartile range) follow-up after SRARP was 16.5 (10.0-30.0) months and 37.0 (18.5-64.0) months after SRT. SRT appeared to confer greater biochemical recurrence-free survival at 1, 2 and 3 years compared with SRARP in high-risk patients (year 3: 86.3% versus 66.0%), but biochemical recurrence-free survival was similar for intermediate-risk patients (year 3: 90.0% versus 75.6%). There was no statistical difference in pad-free continence at 12 and 24 months between SRARP (77.2 and 84.7%) and SRT (75.0 and 74.0%) (P = 0.724, 0.114). Erectile function was more likely to be preserved in men who underwent SRT. After SRT, cumulative bowel and urinary Radiation Therapy Oncology Group toxicity grade I were 25.0 and 45.0%, grade II were 11.0 and 11.0% and grade III or IV complications were 4.0 and 5.0%, respectively.

CONCLUSION

We report the first comparative analyses of salvage prostatectomy and radiotherapy following ablative therapy. Men with high-risk disease appear to have superior oncological outcomes after SRT; however, treatment allocation does not appear to influence oncological outcomes for men with intermediate-risk disease. Treatment allocation was associated with a different spectrum of toxicity profile. Our data may inform shared decision-making when considering salvage treatment following focal or whole-gland ablative therapy.

Clinical predictors of severe late urinary toxicity after curative intensity-modulated radiation therapy for localized prostate cancer

Intractable late urinary toxicity is a serious complication after radiotherapy for patients with localized prostate cancer (LPC). We assessed clinical factors correlated with severe late urinary toxicity in LPC treated with curative image-guided intensity-modulated radiation therapy (IMRT). A total of 452 patients with LPC treated with IMRT between 2002 and 2016 were retrospectively analyzed. Among them, 432 patients received androgen deprivation therapy (ADT). The median total irradiated doses were 80 (range, 76-80) Gy. Each daily dose was 2 Gy per fraction. The median follow-up was 83 (range, 4-210) months. Late urinary toxicity was scored according to the National Cancer Institute Common Terminology Criteria for Adverse Events, Version 4.03. Grade 3 late urinary toxicity was observed in 27 patients. No cases with grade ≥ 4 late urinary toxicity were observed. The 5-, 10-, and 12.5-year grade 3 late urinary toxicity-free survival rates were 97%, 91.8% and 88.1%, respectively. Age, risk classification, total irradiated dose, ADT duration, antithrombotic therapy (AT), cardiovascular disease, hypertension (HT), diabetes mellitus (DM), dyslipidemia (DL), prior transurethral resection of the prostate (TURP) and prior high-intensity focused ultrasound (HIFU) were investigated for correlations with grade 3 late urinary toxicity. In univariate analysis, AT and prior HIFU and no other studied factors, were correlated with grade 3 late urinary toxicity. AT and prior HIFU appear to be predictive of grade 3 late urinary toxicity. Patients with LPC with these relevant clinical factors should be carefully followed up by sharing detailed information with the urology department.

Outcomes of the RAFT trial: robotic surgery after focal therapy

OBJECTIVES

To report toxicity of treatment observed in men participating in the Robotic surgery After Focal Therapy (RAFT) clinical trial.

PATIENTS AND METHODS

Men were eligible for this prospective single group interventional study if they had histologically confirmed recurrent/residual prostate adenocarcinoma following primary FT. The short-form Expanded Prostate Cancer Index Composite (EPIC-26) measured prior to salvage robotic prostatectomy (S-RARP) and 3-monthly post-operatively together with Clavien-Dindo complications (I-IV). Secondary outcomes included biochemical recurrence-free survival (BCFS) following surgery and need for salvage treatment after surgery. This study is registered with ClinicalTrials.gov NCT03011606.

RESULTS

Twenty-four men were recruited between February 2016 and September 2018. 1 patient withdrew from the trial after consenting and before S-RARP. 23 men completed 12-month post S-RARP follow-up. Median EPIC-26 urinary continence scores initially deteriorated after 3 months (82.4 vs 100) but there was no statistically significant difference from baseline at 12 months (100 vs 100, P = 0.31). Median lower urinary tract symptom scores improved after 12 months compared to baseline (93.8 vs 87.5, P = 0.01). At 12 months, 19/23 (83%) were pad-free and 22/23 (96%) required 0/1 pads. Median sexual function subscale scores deteriorated and remained low at 12 months (22.2 vs 58.3, P < 0.001). Utilising a minimally important difference of nine points, at 12 months after surgery 17/23 (74%) reported urinary continence to be 'better' or 'not different' to pre-operative baseline. The corresponding figure for sexual function (utilising a minimally important difference of 12 points) was 7/23 (30%). There was no statistically significant difference on median bowel/hormonal subscale scores. Only a single patient had a post-operative complication (Clavien-Dindo Grade I). BCFS at 12 months after surgery was 82.6% (95% confidence interval [CI]: 60.1-93.1%) while 4/23 (17%) received salvage radiation.

CONCLUSIONS

The RAFT clinical trial suggests toxicity of surgery after FT is low, with good urinary function outcomes, albeit sexual function deteriorated overall. Oncological outcomes at 12 months appear acceptable.

Triggers and oncologic outcome of salvage radical prostatectomy, salvage radiotherapy and active surveillance after focal therapy of prostate cancer

PURPOSE

Due to the tissue preserving approach of focal therapy (FT), local cancer relapse can occur. Uncertainty exists regarding triggers and outcome of salvage strategies.

METHODS

Patients with biopsy-proven prostate cancer (PCa) after FT for localized PCa from 2011 to 2020 at eight tertiary referral hospitals in Germany that underwent salvage radical prostatectomy (S-RP), salvage radiotherapy (S-RT) or active surveillance (AS) were reported. Prostate specific antigen (PSA) changes, suspicious lesions on mpMRI and histopathological findings on biopsy were analyzed. A multivariable regression model was created for adverse pathological findings (APF) at S-RP specimen. Kaplan-Meier curves were generated to determine oncological outcomes.

RESULTS

A total of 90 men were included. Cancer relapse after FT was detected at a median of 12 months (IQR 9-16). Of 50 men initially under AS 13 received S-RP or S-RT. In total, 44 men underwent S-RP and 13 S-RT. At cancer relapse 17 men (38.6%) in the S-RP group [S-RT n = 4 (30.8%); AS n = 3 (6%)] had ISUP > 2. APF (pT ≥ 3, ISUP ≥ 3, pN + or R1) were observed in 23 men (52.3%). A higher ISUP on biopsy was associated with APF [p = 0.006 (HR 2.32, 97.5% CI 1.35-4.59)] on univariable analysis. Progression-free survival was 80.4% after S-RP and 100% after S-RT at 3 years. Secondary therapy-free survival was 41.7% at 3 years in men undergoing AS. Metastasis-free survival was 80% at 5 years for the whole cohort.

CONCLUSION

With early detection of cancer relapse after FT S-RP and S-RT provide sufficient oncologic control at short to intermediate follow-up. After AS, a high secondary-therapy rate was observed.

Post-HIFU locally relapsed prostate cancer: high-dose salvage radiotherapy guided by molecular imaging

PURPOSE

To evaluate tolerance and biochemical control rates of salvage external beam radiotherapy (EBRT) in patients with local relapse from prostate cancer (PC) after high-intensity focused ultrasound (HIFU) as primary treatment.

METHODS

Twenty-four patients presented biochemical failure of PC. Salvage EBRT to the residual prostate was performed with moderate hypofractionation schedule (MHRT) in 28 fractions (n = 16) or with extreme hypofractionation schedule (SBRT) in 5 fractions (n = 8) by means of image-guided volumetric modulation arc therapy. In case of MHRT, the median dose was 71.4 Gy, whereas in case of SBRT it was 32.5 Gy.

RESULTS

The median follow-up was 28 months. The median PSA nadir was 0.26 ng/mL. In case of MHRT, the median PSA nadir was 0.15 ng/mL and occurred within a median time of 19 months. In case of SBRT, the median PSA nadir was 0.64 ng/mL and occurred within a median time of 8 months. No G3 higher acute or late toxicity after EBRT was observed. Only three patients presented with G2 acute GI toxicity (actinic proctitis). Twelve patients experienced acute G1 GU toxicity: 8/16 of men treated with MHRT and 4/8 of men treated with SBRT. Complete local control of disease was achieved in 23/24 patients (96%).

CONCLUSIONS

Our data confirm the feasibility and the low toxicity of salvage EBRT with both schedules of treatment after HIFU failure. The findings of low acute toxicity and good biochemical control rates are encouraging, but a larger number of patients and a longer follow-up are needed to confirm these results.

High-intensity focused ultrasound as focal therapy of prostate cancer

PURPOSE OF REVIEW

High-intensity focused ultrasound (HIFU) has been widely used for whole gland ablation with large series. HIFU induces immediate and irreversible coagulative necrosis with sharply delineated boundaries making HIFU an attractive treatment option for focal therapy of localized prostate. The treatment can be accurately targeted to a portion of the prostate gland. Unlike radiation, there is no lifetime dose limit, allowing HIFU to be repeated if necessary. Additional radical therapy can be performed involving radical surgery, external beam radiation therapy and cryotherapy. Moreover, HIFU is a minimally invasive therapy that can be performed under spinal anesthesia on an outpatient basis.

RECENT FINDINGS

Focal therapy is a new treatment modality for localized prostate cancer. Different energy can be employed to achieve focal therapy including HIFU. With a transrectal treatment, HIFU is one of the less invasive focal treatments. A systematic review of the literature has been performed to highlight the results of focal HIFU.

SUMMARY

The first published results of focal HIFU are promising. The patient's quality of life and potency are well preserved with good early oncological results.

11C choline PET guided salvage radiotherapy with volumetric modulation arc therapy and hypofractionation for recurrent prostate cancer after HIFU failure: preliminary results of tolerability and acute toxicity

The purpose of this work was to evaluate tolerance, feasibility and acute toxicity in patients undergoing salvage radiotherapy after high-intensity focused ultrasound (HIFU) failure. From 2005 to 2011 a total of 15 patients were treated with HIFU as primary radical treatment. Between July 2011 and February 2013, all 15 patients presented biochemical relapse after HIFU and 11C choline PET documenting intrapostatic-only failure. Salvage EBRT was performed with moderate hypofractionation schedule in 28 fractions with volumetric modulation arc therapy (VMAT). Genito-urinary (GU) and rectal and bowel toxicity were scored by common terminology criteria for adverse events version 4 (CTCAE V.4) scale. Biochemical response was assessed by ASTRO Phoenix criteria. Median age of patients was 67 years (range: 53-85). The median Gleason score was 7 (range: 6-9). The median prostate specific antigen (PSA) at the time of biochemical relapse after HIFU was 5.2 ng/mL (range: 2-64.2). Seven of the 15 patients received androgen deprivation therapy (ADT) started after HIFU failure, interrupted before 11C choline PET and radiotherapy. Median prescribed dose was 71.4 Gy (range: 71.4-74.2 Gy) in 28 fractions. No radiation related major upper gastrointestinal (GI), rectal and GU toxicity were experienced. GU, acute grade 1 and grade 2 toxicities were recorded in 7/15 and 4/15 respectively; bowel acute grade 1 and grade 2 toxicities in 4/15 and 1/15; rectal acute grade 1 and grade 2 toxicities in 3/15 and 2/15 respectively. No grade 3 or greater acute or late toxicities occurred. Biochemical control was assessed in 12/15 (80%) patients. With a median follow up of 12 months, three out of 15 patients, with biochemical relapse, showed lymph-nodal recurrence. Our early clinical results and biochemical data confirm the feasibility and show a good tolerance of the 11C choline PET guided salvage radiation therapy after HIFU failure. The findings of low acute toxicity is encouraging, but longer follow-up is needed to assess late toxicity and definitive outcomes.

Management of biochemical recurrence after primary treatment of prostate cancer: a systematic review of the literature

CONTEXT

Despite excellent cancer control with the treatment of localized prostate cancer (PCa), some men will experience a recurrence of disease. The optimal management of recurrent disease remains uncertain.

OBJECTIVE

To systematically review recent literature regarding management of biochemical recurrence after primary treatment for localized PCa.

EVIDENCE ACQUISITION

A comprehensive systematic review of the literature was performed from 2000 to 2012 to identify articles pertaining to management after recurrent PCa. Search terms included prostate cancer recurrence, salvage therapy, radiorecurrent prostate cancer, post HIFU, post cryoablation, postradiation, and postprostatectomy salvage. Studies were selected according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and required to provide a comprehensive description of primary and secondary treatments along with outcomes.

EVIDENCE SYNTHESIS

The data from 32 original publications were reviewed. The most common option for local salvage therapy after radical prostatectomy (RP) was radiation. Options for local salvage therapy after primary radiation included RP, brachytherapy, and cryotherapy. Different definitions of recurrence and risk profiles among patients make comparative assessment among salvage treatment modalities difficult. Triggers for intervention and factors predicting response to salvage therapy vary.

CONCLUSIONS

Radiation therapy (RT) after RP can provide durable prostate-specific antigen (PSA) responses in a sizeable percentage of men, especially when given early (ie, PSA <1 ng/ml). Though a few studies suggest improvements in mortality, prospective randomized trials are needed and underway. The role of salvage treatment after RT is less clear.

Salvage radiotherapy after high intensity focused ultrasound for prostate cancer

High-intensity focused ultrasound (HIFU) is a technique that has been used to treat localised prostate cancer. There is no standard treatment for patients who relapse with prostate cancer following primary treatment with HIFU; here we report the case of a patient who was successfully treated with external beam radiotherapy for disease relapse following HIFU. To date, our patient remains disease free with no toxicity from his treatment.

Prostatic cancer surveillance following whole-gland high-intensity focused ultrasound: comparison of MRI and prostate-specific antigen for detection of residual or recurrent disease

OBJECTIVE

This retrospective study compares dynamic contrast-enhanced (DCE) MRI with the serial prostate-specific antigen (PSA) measurement for detection of residual disease following whole-gland high-intensity focused ultrasound (HIFU) therapy of prostate cancer.

METHODS

Patients in whom post-HIFU DCE-MRI was followed within 3 months by ultrasound-guided transrectal biopsy were selected from a local database. 26 patients met the study inclusion criteria. Serial PSA levels following HIFU and post-HIFU follow-up MRI were retrieved for each patient. Three radiologists unaware of other investigative results independently assessed post-HIFU MRI studies for the presence of cancer, scoring on a four-point scale (1, no disease; 2, probably no disease; 3, probably residual disease; and 4, residual disease). Sensitivity, specificity and receiver operating characteristic (ROC) analysis were performed for each reader, post-HIFU PSA nadir and pre-biopsy PSA level thresholds of >0.2 and >0.5 ng ml(-1).

RESULTS

The sensitivity of DCE-MRI for detection of residual disease for the three readers ranged between 73% and 87%, and the specificity between 73% and 82%. There was good agreement between readers (κ = 0.69-0.77). The sensitivity and specificity of PSA thresholds was 60-87% and 73-100%, respectively. The area under the ROC curve was greatest for pre-biopsy PSA (0.95).

CONCLUSION

DCE-MRI performed following whole-gland HIFU has similar sensitivity and specificity and ROC performance to serial PSA measurements for detection of residual or recurrent disease.