Underutilization of local salvage therapy after radiation therapy for prostate cancer

Salvage low-dose vs high-dose brachytherapy for radio-recurrent prostate cancer

OBJECTIVE

To summarise the efficacy and toxicity of salvage low-dose-rate brachytherapy (LDR-BT) and compare these findings with the published data on salvage high-dose-rate brachytherapy (HDR-BT).

METHODS

We reviewed PubMed and EMBASE for studies published up to May 2024, mainly focusing on recurrence-free survival (RFS) with salvage LDR-BT across subgroups. We also compared RFS and adverse events with HDR-BT as a secondary objective. We reconstructed survival curves using a semi-automated tool called WebPlotDigitizer, along with a new shiny application integrated with R.

RESULTS

A total of 31 studies (891 patients) met the inclusion criteria for salvage LDR-BT. The median RFS of patients treated with salvage LDR-BT was 131.6 months, with 2-, 3- and 5-year rates of 84.6%, 74.3% and 63.5%. Lower median age (65-70 years vs 72.3-75 years, hazard ratio [HR] 0.50, 95% confidence interval [CI] 0.35-0.70; P < 0.0001) and higher adjuvant androgen deprivation therapy (ADT) proportion (83.8%-100% vs 0%-47%, HR 0.60, 95% CI 0.55-0.65; P = 0.036) were positive RFS factors. Compared to HDR-BT, salvage LDR-BT demonstrated improved RFS for all patients (HR 0.67, 95% CI 0.55-0.81; P < 0.0001). Specifically, salvage LDR-BT exhibited superior RFS (P < 0.05) for patients with a median age ≤70 years at recurrence, a median time from primary treatment to salvage therapy (TPTS) of ≥70 months, a median pre-salvage prostate-specific antigen level of ≥5 ng/mL, and a proportion of adjuvant ADT of ≥53%, compared to HDR-BT. However, LDR-BT was associated with a higher rate of severe gastrointestinal (GI; 3.5% vs 0.3%, odds ratio [OR] 0.08, 95% CI 0.03-0.28; P < 0.0001) and genitourinary (GU) toxicities (12.7% vs 5.8%, OR 0.42, 95% CI 0.30-0.60; P < 0.001) compared to HDR-BT.

CONCLUSIONS

In specific cohorts, salvage LDR-BT appears to yield superior RFS but entails a higher incidence of severe GI/GU toxicities compared to HDR-BT.

Multicentric evaluation of recurrence's management after brachytherapy for localized prostate cancer

INTRODUCTION AND BACKGROUND

The treatment of biochemical recurrence (BCR) after low-dose rate Brachytherapy (LDR-BT) for prostate cancer (PCa) includes local salvage therapy (LST) in case of localized recurrence, while systemic treatment is applied in metastatic cases. However, LST is rarely offered due to challenges in identifying the recurrence site. This study compared the recurrence's management after prostate LDR-BT among 2 French and 1 Canadian academic expert center, analyzing the detection and treatment of recurrences.

MATERIAL AND METHODS

The RECCURIE project is a population-based retrospective cohort study including all patients presenting with BCR after treatment with LDR-BT for PCa in the 3 centers involved.

RESULTS

A total of 120 relapsing patients, pretreated with prostate LDR-BT in Paris, France (n=20); Reims, France (n=29); and Montreal, Canada (n=71), for low or intermediate-risk PCa, with a median follow-up of 82.8months, were included. When BCR occurs, the recurrence patterns differed between the centers, with exclusive biological recurrence, or clinically detected localized recurrence in 70 to 80% of patients while 20 to 30% had metastatic recurrence. A multiparametric Magnetic Resonance Imaging (mpMRI) was performed in only 11-55% of cases at recurrence, as well as prostate biopsy (PB) in 13-34% depending on the center. This suboptimal work-up of recurrence led to an underutilization of LST performed in 18% to 53% of the cases, depending on the realization of previous mpMRI and/or PB for recurrence staging.

CONCLUSIONS

The work-up performed at recurrence after LDR-BT varied between centers, with underutilized imaging and histology at the time of recurrence, leading to less frequent use of LST in favor of palliative ADT, even when a curative treatment was still possible.

LEVEL OF EVIDENCE: 3

Long-term outcomes of salvage high-dose-rate brachytherapy for localized recurrence of prostate cancer following definitive radiation therapy: a retrospective analysis

BACKGROUND

Salvage high-dose-rate brachytherapy (HDR-BT) is a potential treatment for localized recurrence of prostate cancer following definitive radiation therapy. This study aimed to evaluate the long-term safety and efficacy of HDR-BT alone, without androgen deprivation therapy (ADT), in this patient population.

METHODS

We conducted a retrospective analysis of patients with prostate cancer who developed pathologically confirmed local recurrence after definitive radiation therapy and were treated with salvage HDR-BT alone at Kawasaki Medical School Hospital between 2007 and 2021. The prescribed HDR-BT dose was 22 Gy in 2 fractions. Biochemical relapse-free survival (bRFS), cause-specific survival (CSS), and overall survival (OS) were assessed using the Kaplan-Meier method. Adverse events were evaluated based on the Common Terminology Criteria for Adverse Events.

RESULTS

Thirty-five patients were included, with a median follow-up of 66.0 months (range, 8.1-169.1). The 5-year bRFS, CSS, and OS rates were 29.7%, 100%, and 89.3%, respectively. Biochemical recurrence occurred in 21 patients (60.0%). Grade 2 adverse events were reported in eight patients (22.9%), while two (5.7%) experienced grade 3 adverse events. All grade 3 adverse events occurred in patients who had HDR-BT as their initial definitive radiation therapy.

CONCLUSIONS

Salvage HDR-BT without ADT is a safe and effective treatment option for localized prostate cancer recurrence after definitive radiation therapy. It provides excellent CSS rates with acceptable toxicity while potentially reducing the need for ADT. Further prospective studies are warranted to confirm these findings.

Salvage Magnetic Resonance Imaging-guided Transurethral Ultrasound Ablation for Localized Radiorecurrent Prostate Cancer

Background and objective

Toxicity from local salvage therapy for radiorecurrent prostate cancer (PCa) remains a concern. This phase 2 study evaluates the outcomes of salvage magnetic resonance imaging (MRI)-guided transurethral ultrasound ablation (sTULSA).

Methods

Men with biochemically relapsed, biopsy-proven PCa following definitive radiotherapy underwent whole- or partial-gland sTULSA (NCT03350529). Prostate-confined recurrence was confirmed by MRI and prostate-specific membrane antigen (PSMA) positron emission tomography (PET) computed tomography (CT). The primary endpoints were safety (Clavien-Dindo classification) and efficacy (prostate-specific antigen [PSA], PSMA PET-CT, and MRI-targeted biopsy at 12 mo). The secondary endpoints included functional and survival outcomes.

Key findings and limitations

Thirty-nine patients underwent sTULSA (64% whole gland), with a median age of 73 yr (interquartile range [IQR]: 69-77) and PSA of 3.3 ng/ml (IQR: 2-6.2). Three patients had undergone prior salvage therapy, 16 were receiving hormonal therapy at enrollment, and 12 had a history of transurethral interventions. Eighteen patients had incidental urethral strictures on baseline cystoscopy. Over a median follow-up of 40 mo (IQR: 24-55), 56% experienced adverse events. Severe genitourinary toxicity (Clavien-Dindo ≥3 or hospitalization) occurred in 28%, including three patients with puboprostatic fistulas and two patients requiring cystectomy. Leak-free continence was maintained in 53%. At 12 mo, 89% showed no cancer in the targeted area, with a median PSA reduction of 95% (p < 0.001). Five-year metastasis-free, failure-free, and biochemical recurrence-free survival probabilities (95% confidence interval) were 97% (0.93-1.00), 70% (0.54-0.91), and 54% (0.31-0.93), respectively. Limitations included single-arm design and moderate sample size.

Conclusions and clinical implications

It has been observed that sTULSA is effective for radiorecurrent PCa, although genitourinary toxicity remains a concern. Further studies should refine patient selection and treatment parameters to improve safety and tolerability.

Patient summary

In this study, we examined a new treatment called magnetic resonance imaging-guided transurethral ultrasound ablation for prostate cancer that has returned after radiation therapy. We found that the treatment provided effective and lasting cancer control for most patients. However, a notable number of patients experienced significant genitourinary toxicity, including severe adverse effects affecting urinary function. Careful patient selection is crucial to minimize these adverse effects and ensure the best results.

Reirradiation - still navigating uncharted waters?

With the emergence of high-precision radiotherapy technologies such as stereotactic ablative radiotherapy (SABR), MR guided brachytherapy, image guided intensity modulated photon and proton radiotherapy and most recently daily adaptive radiotherapy, reirradiation is increasingly recognized as a viable treatment option for many patients. This includes those with recurrent, metastatic or new malignancies post initial radiotherapy. The primary challenge in reirradiation lies in balancing tumor control against the risk of severe toxicity from cumulative radiation doses to previously irradiated normal tissue. Although technology for precise delivery has advanced at a fast pace, clinical practice of reirradiation still mostly relies on individual expertise, as prospective evidence is scarce, the level of reporting in clinical studies is not standardized and of low quality - especially with respect to cumulative doses received by organs at risk. A recent ESTRO/EORTC initiative proposed a standardized definition of reirradiation and formulated general requirements for minimal reporting in clinical studies [1]. As a consequence we found it timely to convene for an international and interdisciplinary meeting with experts in the field to summarize the current evidence, identify knowledge gaps and explore which best practices can be derived for safe reirradiation. The meeting was held on 15.06.2023 in Zurich and was endorsed by the scientific societies SASRO, DEGRO and ESTRO. Here, we report on available evidence and research priorities in the field of reirradiation, as discussed during the meeting.

Salvage Reirradiation for Locally Recurrent Prostate Cancer: Results From a Prospective Study With 7.2 Years of Follow-Up

PURPOSE

There are no well-established re-treatment options for local recurrence after primary curative radiation therapy for prostate cancer (PCa), as prospective studies with long-term follow-up are lacking. Here, we present results from a prospective study on focal salvage reirradiation with external-beam radiation therapy with a median follow-up of 7.2 years.

MATERIALS AND METHODS

From 2013 to 2017, 38 patients with biopsy-proven locally recurrent PCa >2 years after previous treatment and absence of grade 2-3 toxicity from the first course of radiation were included. The treatment was 35 Gy in five fractions to the MRI-based target volume and 6 months of androgen-deprivation therapy starting 3 months before radiation. The Phoenix criteria defined biochemical recurrence-free survival (bRFS), and toxicity was scored according to Radiation Therapy Oncology Group criteria.

RESULTS

Median age was 70 years, and median time from primary radiation to prostate-specific antigen (PSA) recurrence was 83 months. The actuarial 2-year and 5-year bRFS were 81% (95% CI, 69 to 94) and 58% (95% CI, 49 to 74), respectively. The actuarial 5-year local recurrence-free survival was 93% (95% CI, 82 to 100), metastasis-free survival was 82% (95% CI, 69 to 95), and overall survival was 87% (95% CI, 76 to 98). Two patients (5%) had durable grade 3 genitourinary toxicity, one combined with GI grade 3 toxicity. A PSA doubling time ≤6 months at salvage, a Gleason score >7, and a PSA nadir ≥0.1 ng/mL predicted a worse outcome.

CONCLUSION

Reirradiation with EBRT for locally recurrent PCa after primary curative radiation therapy is clinically feasible and demonstrated a favorable outcome with acceptable toxicity in this prospective study with long-term follow-up.

Nonsurgical salvage options for locally recurrent prostate cancer after primary definitive radiotherapy: a systematic review and meta-analysis

OBJECTIVE

To conduct a meta-analysis to provide the latest evidence of nonsurgical local salvage options in the first-line radiotherapy (RT) failure setting for localized prostate cancer patients.

BACKGROUND

Recurrence of localized prostate cancer after primary RT remains a clinical challenge. There is no consensus on optimal nonsurgical local salvage therapies, which mainly consist of cryotherapy (CRYO), high-intensity focused ultrasound (HIFU), high/low-dose-rate brachytherapy (HDR/LDR), and stereotactic body radiotherapy (SBRT).

METHODS

Our study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The authors systematically searched PubMed, Web of Science, Cochrane Library, and ClinicalTrials.gov up to September 2023 to identify potentially relevant studies. The risk of bias was assessed using the European Association of Urology (EAU) items. Biochemical recurrence-free survival (bRFS) and genitourinary/gastrointestinal toxicities were the outcomes of interest. Pooled rates with 95% CIs were evaluated.

RESULTS

A total of 99 studies comprising 8440 patients were included. The pooled rate of 1-year biochemical control (BC) was highest for LDR (0.88, 95% CI: 0.72-0.95) and lowest for SBRT (0.68, 95% CI: 0.49-0.83). The pooled rate of 5-year BC was highest for CRYO (0.52, 95% CI: 0.33-0.69) and lowest for HDR (0.23, 95% CI: 0.08-0.51). HIFU presented the worst outcome of grade ≥3 genitourinary toxicities (GU3), with a rate of 0.22 (95% CI: 0.12-0.3). Conversely, CRYO (0.09, 95% CI: 0.04-0.14), HDR (0.05, 95% CI: 0.02-0.07), LDR (0.10, 95% CI: 0.06-0.14), and SBRT (0.06, 95% CI: 0.03-0.09) presented low rates of GU3. All subgroups induced a quite low incidence of grade ≥3 gastrointestinal toxicities (GI3).

CONCLUSIONS

Nonsurgical salvage therapies are promising modalities for prostate cancer in the local radiorecurrence setting. Based on the preliminary evidence from this study, CRYO and SBRT might present a relatively steady efficacy of BC with acceptable treatment-related toxicities.

Nadir prostate-specific antigen after salvage cryotherapy as a potential prognostic factor for oncologic outcomes

PURPOSE

To report oncologic outcomes of patients undergoing salvage cryotherapy (SCT) for local recurrence of prostate cancer (PCa) and to establish a nadir PSA (nPSA) value that best defines long-term oncologic success.

METHODS

Retrospective study of men who underwent SCT for local recurrence of PCa between 2008 and 2020. SCT was performed in men with biochemical recurrence (BCR), after primary treatment and with biopsy-proven PCa local recurrence. Survival analysis with Kaplan-Meier and Cox models was performed. We determined the optimal cutoff nPSA value after SCT that best classifies patients depending on prognosis.

RESULTS

Seventy-seven men who underwent SCT were included. Survival analysis showed a 5-year biochemical recurrence-free survival (BRFS), androgen deprivation therapy-free survival (AFS), and metastasis-free survival (MFS) after SCT of 48.4%, 62% and 81.3% respectively. On multivariable analysis for perioperative variables associated with BCR, initial ISUP, pre-SCT PSA, pre-SCT prostate volume and post-SCT nPSA emerged as variables associated with BCR. The cutoff analysis revealed an nPSA < 0.5 ng/ml to be the optimal threshold that best defines success after SCT. 5-year BRFS for patients achieving an nPSA < 0.5 vs nPSA ≥ 0.5 was 64% and 9.5% respectively (p < 0.001). 5-year AFS for men with nPSA < 0.5 vs ≥ 0.5 was 81.2% and 12.2% (p < 0.001). Improved 5-year MFS for patients who achieved nPSA < 0.5 was also obtained (89.6% vs 60%, p = 0.003).

CONCLUSION

SCT is a feasible rescue alternative for the local recurrence of PCa. Achieving an nPSA < 0.5 ng/ml after SCT is associated with higher long-term BRFS, AFS and MFS rates.

Magnetic resonance guided SBRT reirradiation in locally recurrent prostate cancer: a multicentric retrospective analysis

AIMS

Reirradiation of prostate cancer (PC) local recurrences represents an emerging challenge for current radiotherapy. In this context, stereotactic body radiation therapy (SBRT) allows the delivery of high doses, with curative intent. Magnetic Resonance guided Radiation Therapy (MRgRT) has shown promising results in terms of safety, feasibility and efficacy of delivering SBRT thanks to the enhanced soft tissue contrast and the online adaptive workflow. This multicentric retrospective analysis evaluates the feasibility and efficacy of PC reirradiation, using a 0.35 T hybrid MR delivery unit.

METHODS

Patients affected by local recurrences of PC and treated in five institutions between 2019 and 2022 were retrospectively collected. All patients had undergone previous Radiation Therapy (RT) in definitive or adjuvant setting. Re-treatment MRgSBRT was delivered with a total dose ranging from 25 to 40 Gy in 5 fractions. Toxicity according to CTCAE v 5.0 and treatment response were assessed at the end of the treatment and at follow-up.

RESULTS

Eighteen patients were included in this analysis. All patients had previously undergone external beam radiation therapy (EBRT) up to a total dose of 59.36 to 80 Gy. Median cumulative biologically effective dose (BED) of SBRT re-treatment was 213,3 Gy (103,1-560), considering an α/β of 1.5. Complete response was achieved in 4 patients (22.2%). No grade ≥ 2 acute genitourinary (GU) toxicity events were recorded, while gastrointestinal (GI) acute toxicity events occurred in 4 patients (22.2%).

CONCLUSION

The low rates of acute toxicity of this experience encourages considering MRgSBRT a feasibile therapeutic approach for the treatment of clinically relapsed PC. Accurate gating of target volumes, the online adaptive planning workflow and the high definition of MRI treatment images allow delivering high doses to the PTV while efficiently sparing organs at risk (OARs).

Salvage stereotactic body radiation therapy for locally recurrent prostate cancer following primary radiation therapy, are benefits worth toxicity risks?: A systematic review

INTRODUCTION

Salvage stereotactic body radiation therapy (SBRT) for localized prostate cancer recurrence following radiation therapy remains controversial. We performed a systematic review to assess the efficacy and side effect profile of salvage SBRT for locally recurrent prostate cancer to define the role of salvage SBRT in clinical practice.

METHODS

A systematic review was carried out using Pubmed (MEDLINE) and Scopus databases. Inclusion and exclusion criteria were satisfied if studies reported on patients with prior radiation therapy for prostate cancer who had subsequently had a local recurrence. Those studies included were quality assessed using the ROBINS-I checklist.

RESULTS

Five studies in total met criteria for inclusion and included all reportable outcomes. A total of 265 participants are reported on in total. Median doses for SBRT ranged from 30 to 36 Gy delivered over 5-6 fractions. Recurrence free survival ranged from 40% to 76% at 2 years. Genitourinary toxicity was more prevalent than gastrointestinal toxicities. Grade 2 and 3 genitourinary complication rates ranged from 5% to 22% and 0% to 9%, respectively. Gastrointestinal grade 2 complication rates ranged from 0% to 11% and no grade 3 complications were recorded.

DISCUSSION

Salvage SBRT appears to be comparable and potentially superior in some aspects to other salvage therapies, taking into account the limitations in cross-study comparisons. This systematic review serves as one of the first to characterize SBRT as a salvage option for locally recurrent prostate cancer.

Salvage Prostate Brachytherapy in Radiorecurrent Prostate Cancer: An International Delphi Consensus Study

BACKGROUND AND PURPOSE

Local recurrences after previous radiotherapy (RT) are increasingly being identified in biochemically recurrent prostate cancer. Salvage prostate brachytherapy (BT) is an effective and well tolerated treatment option. We sought to generate international consensus statements on the use and preferred technical considerations for salvage prostate BT.

MATERIALS AND METHODS

International experts in salvage prostate BT were invited (n=34) to participate. A three-round modified Delphi technique was utilized, with questions focused on patient- and cancer-specific criteria, type and technique of BT, and follow-up. An a priori threshold for consensus of ≥ 75% was set, with a majority opinion being ≥ 50%.

RESULTS

Thirty international experts agreed to participate. Consensus was achieved for 56% (18/32) of statements. Consensus was achieved in several areas of patient selection: 1) A minimum of 2-3 years from initial RT to salvage BT; 2) MRI and PSMA PET should be obtained; and 3) Both targeted and systematic biopsies should be performed. Several areas did not reach consensus: 1) Maximum T stage/PSA at time of salvage; 2) Utilization/duration of ADT; 3) Appropriateness of combining local salvage with SABR for oligometastatic disease and 4) Repeating a second course of salvage BT. A majority opinion preferred High Dose-Rate salvage BT, and indicated that both focal and whole gland techniques could be appropriate. There was no single preferred dose/fractionation.

CONCLUSION

Areas of consensus within our Delphi study may serve as practical advice for salvage prostate BT. Future research in salvage BT should address areas of controversy identified in our study.

Salvage stereotactic reirradiation for intraprostatic cancer recurrence: A large retrospective study

INTRODUCTION

Prostate cancer is the most common cancer in men. Thirty to forty-seven percent of patients treated with exclusive radiotherapy for prostate cancer will experience intraprostate recurrence. The use of radiotherapy in stereotactic conditions allows millimetric accuracy in irradiation to the target zone that minimizes the dose to organs at risk. In this study, we evaluated the clinical outcome of prostatic reirradiation with stereotactic body radiation therapy (SBRT) in patients with intraprostatic recurrence initially treated by radiotherapy.

METHOD

This single-center retrospective study included 41 patients diagnosed with exclusive local recurrence of prostate cancer after radiotherapy and treatedby stereotactic Cyberknife irradiation. The objective of this study was to assess the efficacy and the safety of stereotactic reirradiation for patients with intraprostatic recurrence initially treated with radiotherapy.

RESULTS

Median follow-up was 35 months. The 2-year biochemical relapse-free survival was 72.89%, the 2-year local recurrence free survival was 93.59%, the 2-year local regional recurrence-free survival was 85.24%, and the 2-year metastasis-free survival was to 91.49%. The analysis of toxicities showed a good tolerance of stereotactic irradiation. Urinary and gastro-intestinal adverse events was mostly of grades 1-2 (CTCAEv4). Grade 3 toxicity occurred in one to two patients.

CONCLUSION

Stereotactic reirradiation appears effective and well-tolerated for local recurrence of prostate cancer and might allow to delay the introduction of hormonal therapy and its side effects.

Outcomes of Sterotactic Body Radiotherapy (SBRT) for pelvic lymph node recurrences after adjuvant or primary radiotherapy for prostate cancer

BACKGROUND

There is a paucity of data on the management of recurrent lymph nodes after primary or adjuvant radiotherapy (RT) for prostate cancer (PCa). In this study, we report our tertiary cancer center experience with stereotactic body radiotherapy (SBRT) for the management of pelvic lymph node recurrences after adjuvant or primary RT for PCa.

MATERIALS AND METHODS

Patients who underwent SBRT for pelvic lymph node metastases from PCa between 2013 and 2019 were retrospectively assessed for local control (LC), androgen deprivation treatment-free survival (ADT-FS), and toxicity outcomes. The primary endpoint was LC and ADT-FS. The secondary endpoint was late treatment toxicity.

RESULTS

Twenty-two lesions of 18 patients receiving SBRT for pelvic lymph node recurrences for PCa between February 2013 and March 2019 were evaluated. At a median follow-up duration of 29.5 months (range: 9-54 months), LC was 95.5% vs. 90.2% at 1 and 2 years, respectively. Ten patients received palliative ADT following SBRT after a median period of 14.5 months (range: 6-31 months). ADT-FS was 72.2% and 54.3% at 1 and 2 years, respectively. Comparative analysis of biologically effective dose (BED) values revealed that higher BED10 values were associated with higher ADT-FS (P = 0.008). ADT-FS was 55.6% and 88.9% for BED10 <50 Gy and for BED10 >50 Gy, respectively (P = 0.008). Assessment of late toxicity outcomes revealed that the most common toxicity was urinary toxicity and fatigue; however, no patient had ≥ grade 3 toxicity.

CONCLUSION

Our tertiary cancer center experience confirms the safety and efficacy of SBRT for the management of pelvic lymph node recurrences from PCa.

Evolving imaging methods of prostate cancer and the emergence of magnetic resonance imaging guided ablation techniques

Established therapies for prostate cancer (PCa), surgery and radiotherapy, treat the entire gland regardless of the location of the cancerous lesion within the prostate. Although effective, these methods include a significant risk of worsening genitourinary outcomes. Targeted image-guided cancer therapy has gained acceptance through improved PCa detection, localization, and characterization by magnetic resonance imaging (MRI). Minimally-invasive ablative techniques aim to achieve comparable oncological outcomes to radical treatment while preserving genitourinary function. Transurethral ultrasound ablation (TULSA) and next-generation transrectal high-intensity focused ultrasound (HIFU) utilize MRI guidance to thermally ablate prostate tissue under real-time MRI monitoring and active temperature feedback control. Previous trials performed by our group and others, including a large multicenter study in men with localized favorable-risk disease, have demonstrated that TULSA provides effective prostate ablation with a favorable safety profile and low impact on quality of life. Recently, MRI-guided HIFU focal therapy was also shown as a safe and effective treatment of intermediate-risk PCa. Here we review the current literature on ablative techniques in the treatment of localized PCa with a focus on TULSA and HIFU methods.

Oncological and urinary outcomes following low-dose-rate brachytherapy with a median follow-up of 11.8 years

OBJECTIVES

To examine the long-term oncological outcomes and urological morbidity of low-dose-rate prostate brachytherapy (LDRBT) monotherapy using live intraoperative dosimetry planning and an automated needle navigation delivery system for the treatment of men with low and intermediate-risk prostate cancer.

PATIENTS AND METHODS

A prospective database of 400 consecutive patients who underwent LDRBT between July 2003 and June 2015 was retrospectively reviewed to assess urinary side-effects and biochemical progression, based on the Phoenix definition and also a definition of a prostate-specific antigen (PSA) level of ≥0.2 μg/L.

RESULTS

Minimum patient follow-up was 5.5 years. The median follow-up of the entire cohort was 11.8 years. The median (range) PSA level was 6.1 (0.9-17) μg/L and the median Gleason score was 3 + 4. The biochemical relapse-free survival (RFS; freedom from biochemical recurrence) based on the Phoenix definition was 85.8% (343/400). The RFS using a 'surgical' definition of a PSA level of <0.2 μg/L was 71% (284/400). Of the 297 men followed for ≥10 years, prostate cancer-specific survival (PCSS) was 98% (291/297). Post-LDRBT urethral stricture developed in 11 men (2.8%, 11/400). For men with ≥10 years of follow-up, 22 men (7.4%, 22/297) required a pad for either stress or urge urinary incontinence (UI). UI was identified in only 2.2% (one of 46) of men who had a bladder neck incision (BNI) before LDRBT.

CONCLUSION

LDRBT is associated with excellent PCSS, with a median follow-up of 11.8 years. The risk of post-implantation urethral stricture and UI is low and a pre-implantation BNI for management of bladder outflow obstruction does not increase the risk of UI or urethral stricture.

MRI-guided focal or integrated boost high dose rate brachytherapy for recurrent prostate cancer

Background and purpose

Locally recurrent prostate cancer after radiotherapy merits an effective salvage strategy that mitigates the risk of adverse events. We report outcomes of a cohort enrolled across two institutions investigating MRI-guided tumor-targeted salvage high dose rate brachytherapy (HDR-BT).

Materials and methods

Analysis of a prospective cohort of 88 patients treated across two institutions with MRI-guided salvage HDR-BT to visible local recurrence after radiotherapy (RT). Tumor target dose ranged from 22-26 Gy, using either an integrated boost (ibBT) or focal technique (fBT), delivered in two implants over a median of 7 days. Outcome metrics included cancer control and toxicity (CTCAE). Quality of life (QoL-EPIC) was analyzed in a subset.

Results

At a median follow-up of 35 months (6 -134), 3 and 5-year failure-free survival (FFS) outcomes were 67% and 49%, respectively. At 5 years, fBT was associated with a 17% cumulative incidence of local failure (LF) outside the GTV (vs. 7.8% ibBT, p=0.14), while LF within the GTV occurred in 13% (vs. 16% ibBT, p=0.81). Predictors of LF outside fBT volumes included pre-salvage PSA>7 ng/mL (p=0.03) and interval since RT less than 5 years (p=0.04). No attributable grade 3 events occurred, and ibBT was associated with a higher rate of grade 2 toxicity (p<0.001), and trend towards a larger reduction in QoL sexual domain score (p=0.07), compared to fBT.

Conclusion

A tumor-targeted HDR-BT salvage approach achieved favorable cancer control outcomes. While a fBT was associated with less toxicity, it may be best suited to a subgroup with lower PSA at later recurrence. Tumor targeted dose escalation may be warranted.

Value of Targeted Biopsies and Combined PSMA PET/CT and mp-MRI Imaging in Locally Recurrent Prostate Cancer after Primary Radiotherapy

Simple Summary

After primary radiotherapy for prostate cancer, patients may develop an isolated local recurrence. The diagnostic workup of these recurrences guides decision making for potential focal salvage treatments. The aim of this study was to determine the positive predictive value (PPV) of combined multiparametric (mp) MRI and prostate specific membrane antigen (PSMA) PET/CT imaging in this setting, with histological conformation using MR-guided targeted biopsies. In 41 patients counseled for focal salvage high dose rate (HDR) brachytherapy, a PPV of 97.6% was found for combined mp-MRI and PSMA PET/CT. Therefore, biopsies can safely be omitted in these patients.

Abstract

Radiorecurrent prostate cancer is conventionally confirmed using systematic and/or targeted biopsies. The availability of multiparametric (mp) MRI and prostate specific membrane antigen (PSMA) PET/CT has increased diagnostic accuracy. The objective was to determine the positive predictive value (PPV) of combined mp-MRI and PSMA PET/CT and whether pathology verification with MR-targeted biopsies remains necessary for patients with radiorecurrent prostate cancer. Patients with locally recurrent prostate cancer who were referred for 19 Gy single-dose MRI-guided focal salvage high dose rate (HDR) brachytherapy between 2015 and 2018 were included in the current analysis. Patients were selected if they underwent pre-biopsy mp-MRI and PSMA PET/CT. Based on these images, lesions suspect for isolated tumor recurrence were transperineally biopsied using transrectal ultrasound fused with MRI. A total of 41 patients were identified from the database who underwent cognitive targeted (n = 7) or MRI/PSMA-transrectal ultrasound (TRUS) fused targeted (n = 34) biopsies. A total of 40 (97.6%) patients had positive biopsies for recurrent cancer. Five patients initially had negative biopsies (all MRI/PSMA-TRUS fusion targeted), four of whom recurrence was confirmed after a re-biopsy. One (2.4%) patient refused re-biopsy, leading to a positive predictive value (PPV) for combined imaging of 97.6%. Biopsies can therefore safely be withheld when the results of the combined mp-MRI and PSMA PET/CT are conclusive, avoiding an unnecessary invasive and burdensome procedure.

Defining radio-recurrent intra-prostatic target volumes using PSMA-targeted PET/CT and multi-parametric MRI

PURPOSE

Our purpose was to evaluate intra-prostatic cancer volumes for salvage radiotherapy in men with recurrent prostate cancer confined to the prostate post-primary radiotherapy using mpMRI and 18F-DCFPyL PET/CT (PET).

METHODS

Men with biochemical failure post-primary radiotherapy were enrolled in a multi-centre trial investigating mpMRI and PET. All men with isolated intra-prostatic recurrence are included in this secondary analysis. The intra-prostatic gross tumour volume (GTV) was manually delineated on mpMRI and was also delineated on PET using three methods: 1. manually, 2. using a 30% threshold of maximum intra-prostatic standard uptake value (SUVmax), and 3. using a 67% threshold of this SUVmax. Clinical target volumes (CTV) including expansions on each GTV were generated. Conformity indices were performed between the mpMRI CTV and each PET CTV. Correlation with biopsy and clinical outcomes were performed.

RESULTS

Of the 36 men included, 30 (83%) had disease in two quadrants or less using the combination of mpMRI and PET. Mean target volume (union of CTV on mpMRI and CTV manually delineated on PET) was 12.2 cc (49% of prostate gland volume). 12/36 (33%) men had a biopsy. Per-patient sensitivity was 91% for mpMRI and 82% for PET.

CONCLUSIONS

mpMRI and PET provide complementary information for delineation of intra-prostatic recurrent disease. Union of CTV on mpMRI and PET is often less than 50% of the prostate, suggesting this imaging could help define a target for focal salvage therapy.

Stereotactic Re-irradiation in Recurrent Prostate Cancer after Previous Postoperative or Definitive Radiotherapy: Long-term Results after a Median Follow-up of 4 Years

AIMS

In 2018, we published early results from a cohort of patients treated with stereotactic body radiotherapy (SBRT) after previous radiotherapy with definitive or postoperative intent. We sought to provide extended follow-up of this cohort to confirm the safety and efficacy of this approach in a real-world scenario.

MATERIALS AND METHODS

Fifty patients affected by local relapse after previous definitive or postoperative radiotherapy were treated with SBRT. Treatment provided a total dose of 30 Gy in five fractions. Data about biochemical relapse-free survival (BRFS) and metastasis-free survival (MFS), together with adverse events, were analysed. Toxicity was reported according to Common Terminology Criteria for Adverse Events (CTCAE) score v.4.03.

RESULTS

After a median follow-up of 48.2 months, the median BRFS was 43 months. A Gleason score >7 and concomitant androgen deprivation therapy were shown to be predictors of the worst BRFS (hazard ratio 2.42, 95% confidence interval 1.09-5.41, P = 0.02; hazard ratio 2.83, 95% confidence interval 1.17-6.8, P = 0.02, respectively). The median MFS was not reached; concomitant androgen deprivation therapy was confirmed to be predictive of the worst MFS (hazard ratio 4.75, 95% confidence interval 1.52-14.8, P = 0.007). Late grade 1 and 2 rectal and bladder toxicity occurred in three (6%) and 13 (26%) patients, respectively. One patient experienced both grade 3 acute and chronic bladder toxicity.

CONCLUSION

Salvage SBRT re-irradiation after previous postoperative or definitive radiotherapy for local prostate cancer recurrence confirmed promising results in terms of oncological outcomes and the safety of this approach.

Salvage Low Dose Rate Prostate Brachytherapy: Clinical Outcomes of a Phase II Trial for Local Recurrence after External Beam Radiotherapy (NRG Oncology/xxxx)

PURPOSE

We report efficacy of a prospective Phase II trial (YYYY) of salvage low dose rate (LDR) prostate brachytherapy (BT) for local failure (LF) after prior external beam radiotherapy (EBRT) with minimum 5- years' follow up.

MATERIALS/METHODS

Eligible patients had low/intermediate risk prostate cancer (PCa) prior to EBRT and biopsy-proven LF > 30 months after EBRT, with PSA < 10 ng/mL and no regional/distant disease. The primary endpoint, late GI/GU Adverse Events (AEs) (CTCAE V3.0 ≥ Grade 3) was 14%. With minimum 5-year follow up after salvage BT, secondary clinical outcomes including disease-free (DFS; includes death from any cause), disease-specific (DSS), and overall survival (OS) were estimated using the Kaplan-Meier method and modelled using Cox proportional hazards regression. Local tumor progression (LF), distant and biochemical failure (DF/BF) were estimated using cumulative incidence. Time to LF, DF and BF were modeled by cause-specific Cox proportional hazards regression.

RESULTS

From 05/2007 -01/2014, 20 centers registered 100 patients (92 analyzable). Median follow up is 6.7 years (range: 0.3-11.2); median age 70 years (range: 55-82); median prior EBRT dose 74 Gy (IQR: 70-76) at a median of 85 months prior(IQR: 60-119). Androgen deprivation was combined with salvage BT in 16%. 10-year OS is 70% (95% confidence interval [CI]: 58 -83). 19 patients died (5 PCa, 10 other, 4 unknown). 10-year failure rates are local 5% (95% CI:1-11), distant 19% (95% CI:10-29) and biochemical 46% (95% CI:34-57). DFS is 61% at 5 years; 33% at 10 years. No baseline characteristic was significantly associated with any clinical outcome.

CONCLUSION

This is the first prospective multicenter trial reporting outcomes of salvage LDR BT for LF after EBRT. Five-year freedom from BF is 68%, comparable to other salvage modalities. Although further LF is rare (5%), BF climbs to 46% by10-years.

Health service underutilization and its associated factors for chronic diseases patients in poverty-stricken areas in China: a multilevel analysis

Background

Underutilization of health services among chronic non-communicable disease sufferers, especially for hypertension (HBP) and diabetes mellitus (DM), was considered as a significant contributing factor to substantial cases in terms of both avoidable morbidity and mortality. However, evidence on health services underutilization and its associated factors in poverty-stricken areas remain scarce based on previous literature. This study aims to describe health services underutilization for people diagnosed with chronic diseases in impoverished regions and to identify its associated factors, which are expected to provide practical implications for the implementations of interventions tailored to the specific needs of disadvantaged residents in rural China to achieve effective utilization of health services in a timely manner.

Methods

Data were collected from a cross-sectional survey conducted through face-to-face interviews among 2413 patients from six counties in rural central China in 2019. The Anderson behavioral model was adopted to explore the associated factors. A two-level logistic model was employed to investigate the association strengths reflected by adjusted odds ratios (AOR) and 95% confidence intervals in forest plots.

Results

On average, 17.58% of the respondents with HBP and 14.87% with DM had experienced health services underutilization during 1 month before the survey. Multilevel logistic regression indicated that predisposing factors (age), enabling factors (income and a regular source of care), and need factors (self-reported health score) were the common predictors of health service underutilization both for hypertensive and diabetic patients in impoverished areas, among which obtaining a regular source of care was found to be relatively determinant as a protective factor for health services underutilization after controlling for other covariates.

Conclusions

Our results suggested that the implementation of a series of comprehensive strategies should be addressed throughout policy-making procedures to improve the provision of regular source of care as a significant determinant for reducing health services underutilization, thus ultimately achieving equal utilization of health services in impoverished regions, especially among chronic disease patients. Our findings are expected to provide practical implications for other developing countries confronted with similar challenges resulting from underdeveloped healthcare systems and aging population structures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06725-5.

Salvage re-irradiation using stereotactic body radiation therapy for locally recurrent prostate cancer: the impact of castration sensitivity on treatment outcomes

Background

Advances in imaging, biomaterials and precision radiotherapy provide new opportunities to salvage locally recurrent prostate cancer (PC). This study evaluates the efficacy and safety of re-irradiation using stereotactic body radiation therapy (SBRT). We hypothesized that patients with castrate-resistant PC (CRPC) would benefit less from local salvage.

Methods

A prospective clinical database was reviewed to extract 30 consecutive patients treated with prostate re-irradiation. Gallium prostate specific membrane antigen (PSMA) ligand positron emission tomography was performed following prostate-specific antigen failure in all patients and biopsy was obtained in 18 patients (60%). Re-irradiation was either focal (n = 13) or whole-gland (n = 17). Endo-rectal balloons were used in twenty-two patients and hydrogel spacers in eight patients. The median prescription dose was 5 fractions of 6.5 (range: 6–8) Gray (Gy).

Results

Median follow-up was 28 months. Failure occurred in 10 (out of 11) CRPC patients versus 6 (out of 19) castrate-sensitive patients (91% vs. 32%, p = 0.008) after a median of 13 and 23 months, respectively. Metastases occurred in 64% (n = 7) of CRPC patients versus 16% (n = 3) of castrate-sensitive patients (p = 0.007). Two patients experienced local in-field recurrence, thus local control was 93%. The 2 and 3-year recurrence-free survival were 84% and 79% for castrate-sensitive patients versus 18% and 9% for CRPC patients (p < 0.001), and 3-year metastasis-free survival was 90% versus 27% (p < 0.01) for castrate-sensitive and CRPC patients, respectively. Acute grade II and III genitourinary (GU) toxicity occurred in 27% and 3%, and late GU toxicity in 30% and 3%, respectively. No ≥ grade II acute gastrointestinal (GI) toxicity occurred, and only one patient (3%) developed late grade II toxicity.

Conclusions

Early delivery of salvage SBRT for local recurrence is associated with excellent 3-year disease control and acceptable toxicity in the castrate-sensitive phenotype. PSMA imaging for detection of local recurrence and the use of precision radiotherapy with rectal protective devices should be further investigated as a novel salvage strategy for radio-recurrent PC.

Salvage High-Dose-Rate Brachytherapy for Recurrent Prostate Cancer After Definitive Radiation

PURPOSE

Salvage high-dose-rate brachytherapy (sHDRBT) for locally recurrent prostate cancer after definitive radiation is associated with biochemical control in approximately half of patients at 3 to 5 years. Given potential toxicity, patient selection is critical. We present our institutional experience with sHDRBT and validate a recursive partitioning machines model for biochemical control.

MATERIALS AND METHODS

We performed a retrospective analysis of 129 patients who underwent whole-gland sHDRBT between 1998 and 2016. We evaluated clinical factors associated with biochemical control as well as toxicity.

RESULTS

At diagnosis the median prostate-specific antigen (PSA) was 7.77 ng/mL. A majority of patients had T1-2 (73%) and Gleason 6-7 (82%) disease; 71% received external beam radiation therapy (RT) alone, and 22% received permanent prostate implants. The median disease-free interval (DFI) was 56 months, and median presalvage PSA was 4.95 ng/mL. At sHDRBT, 46% had T3 disease and 51% had Gleason 8 to 10 disease. At a median of 68 months after sHDRBT, 3- and 5-year disease-free survival were 85% (95% CI, 79-91) and 71% (95% CI, 62-79), respectively. Median PSA nadir was 0.18 ng/mL, achieved a median of 10 months after sHDRBT. Patients with ≥35%+ cores and a DFI <4.1 years had worse biochemical control (19% vs 50%, P = .02). Local failure (with or without regional/distant failure) was seen in 11% of patients (14/129), and 14 patients (11%) developed acute urinary obstruction requiring Foley placement and 19 patients (15%) developed strictures requiring dilation.

CONCLUSIONS

sHDRBT is a reasonable option for patients with locally recurrent prostate cancer after definitive RT. Those with <35%+ cores or an initial DFI of ≥4.1 years may be more likely to achieve long-term disease control after sHDRBT.

Defining the index lesion for potential salvage partial or hemi-gland ablation after radiation therapy for localized prostate cancer

BACKGROUND

Salvage partial gland ablation (sPGA) has been proposed to treat some localized radiorecurrent prostate cancer. The role of prostate biopsy and magnetic resonance imaging (MRI) characteristics to identify patients eligible for sPGA is unknown.

OBJECTIVE

To evaluate the ability of MRI and prostate biopsy characteristics to identify an index lesion suitable for sPGA and validate this selection using detailed tumor maps created from whole-mount slides from salvage radical prostatectomy (sRP) specimens.

DESIGN, SETTING, AND PARTICIPANTS

Men who underwent sRP for recurrent prostate cancer following primary radiotherapy with external beam radiotherapy (EBRT) and/or brachytherapy between 2000 and 2014 at a single high-volume cancer center were eligible. Those with tumor maps, MRI and biopsy data were included in analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary outcome was the ability of clinicopathologic and imaging criteria to identify patients who may be eligible for sPGA based on detailed tumor map from whole-mount sRP slides.

RESULTS AND LIMITATIONS

Of 216 men who underwent sRP following whole gland radiotherapy, tumor maps, MRI, and biopsy data were available for 77. Of these, 15 (19%) were determined to be eligible for sPGA based on biopsy-proven unilateral disease in contiguous sextant segments, a dominant lesion on MRI concordant with biopsy location or no focal region of interest, and no imaging evidence of extraprostatic disease. Review of tumor maps identified 6 additional men who would have met criteria for sPGA, resulting in sensitivity of 71% (95% C.I. 48%-89%) and specificity of 100% (lower bound of 95% C.I. 94%). None of the 15 men who met the criteria for sPGA on clinical data were identified incorrectly on tumor maps to require full gland surgery (upper bound of 95% C.I. 22%). Median tumor volume of the index lesion was 0.4 cc and recurrent cancer was noted in the apex, mid-gland, and base in 81%, 100%, and 29% of men.

CONCLUSIONS

In men with recurrent prostate cancer after radiotherapy, biopsy findings and MRI can be used to select index lesions potentially amenable for sPGA and can guide patient evaluation for inclusion in clinical trials of sPGA following radiation failure. Larger, prospective studies are required to evaluate both the role of MRI and clinical criteria in guiding focal salvage therapy and the effectiveness of this modality for radiorecurrent prostate cancer.

Salvage Magnetic Resonance Imaging-guided Transurethral Ultrasound Ablation for Localized Radiorecurrent Prostate Cancer: 12-Month Functional and Oncological Results

Background

Up to half of all men who undergo primary radiotherapy for localized prostate cancer (PCa) experience local recurrence.

Objective

To evaluate the safety and early functional and oncological outcomes of salvage magnetic resonance imaging-guided transurethral ultrasound ablation (sTULSA) for men with localized radiorecurrent PCa.

Design setting and participants

This prospective, single-center phase 1 study (NCT03350529) enrolled men with biopsy-proven localized PCa recurrence after radiotherapy. Multiparametric magnetic resonance imaging (mpMRI) and ¹⁸F prostate-specific membrane antigen-1007 (¹⁸F PSMA-1007) positron emission tomography (PET)-computed tomography (CT) were used to confirm organ-confined disease localization. Patients underwent either whole-gland or partial sTULSA, depending on their individual tumor characteristics.

Outcome measurements and statistical analysis

Patients were followed at 3-mo intervals. Adverse events (AEs, Clavien-Dindo scale), functional status questionnaires (Expanded Prostate Cancer Index [EPIC]-26, International Prostate Symptom Score, International Index of Erectile Function-5), uroflowmetry, and prostate-specific antigen (PSA) were assessed at every visit. Disease control was assessed at 1 yr using mpMRI and ¹⁸F-PSMA-1007 PET-CT, followed by prostate biopsies.

Results and limitations

Eleven patients (median age 69 yr, interquartile range [IQR] 68-74) underwent sTULSA (3 whole-gland, 8 partial sTULSA) and have completed 12-mo follow-up. Median PSA was 7.6 ng/ml (IQR 4.9-10) and the median time from initial PCa diagnosis to sTULSA was 11 yr (IQR 9.5-13). One grade 3 and three grade 2 AEs were reported, related to urinary retention and infection. Patients reported a modest degradation in functional status, most significantly a 20% decline in the EPIC-26 irritative/obstructive domain at 12 mo. A decline in maximum flow rate (24%) was also observed. At 1 yr, 10/11 patients were free of any PCa in the targeted ablation zone, with two out-of-field recurrences. Limitations include the nonrandomized design, limited sample size, and short-term oncological outcomes.

Conclusions

sTULSA appears to be safe and feasible for ablation of radiorecurrent PCa, offering encouraging preliminary oncological control.

Patient summary

We present safety and 1-yr functional and oncological outcomes of magnetic resonance imaging-guided transurethral ultrasound ablation (TULSA) as a salvage treatment for local prostate cancer recurrence after primary radiation. Salvage TULSA is safe and shows the ability to effectively ablate prostate cancer recurrence, with acceptable toxicity.

Functional and oncological outcomes of salvage cryosurgery for radiorecurrent prostate cancer

OBJECTIVES

To evaluate the oncological and functional outcomes of salvage cryosurgery (SCS) for radiorecurrent prostate cancer (rrPCa).

PATIENTS AND METHODS

A total of 169 consecutive patients with biopsy confirmed rrPCa were retrospectively analysed. All patients underwent SCS in a single referral centre between 2006 and 2018. The primary outcome was biochemical recurrence-free survival (BRFS) according to the Phoenix definition (prostate-specific antigen [PSA] nadir +2 ng/mL). The secondary outcomes were overall survival, BRFS defined as a PSA level of >0.5 ng/mL, metastasis-free survival, androgen-deprivation therapy (ADT)-free survival, and functional outcomes. Complications were classified according to the Clavien-Dindo system. PSA was measured every 3-6 months postoperatively. Functional outcomes were scored as reported by patients at outpatient visits. Kaplan-Meier survival analysis and uni- and multivariable Cox regression were performed.

RESULTS

The median (interquartile range) follow-up was 36 (18-66) months. The BRFS after 5 and 8 years was 52% (95% confidence interval [CI] 43-62%) and 45% (95% CI 35-57%), respectively. At multivariable analysis PSA level at initial diagnosis, initial treatment, interval between primary treatment and SCS, age at SCS, and post-SCS PSA nadir were significant factors for BRFS. The 5-year ADT-free survival was 70% (95% CI 62-79%). Clavien-Dindo Grade ≥III complications occurred in 1.2% (two/169) of patients. In all, 19% (29/156) of patients had new-onset urinary incontinence defined as >1 pad/24 h and 92% (57/62) of patients had new-onset erectile dysfunction. Persistent urinary fistula occurred in 6.5% (11/169) of patients.

CONCLUSIONS

The present study shows acceptable oncological outcomes of SCS considering the salvage character of the treatment. The occurrence of serious complications such as urinary incontinence and fistula should not be underestimated.

Health-related quality of life after ultrafocal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer: reporting the patient’s perspective

•

We analyzed patient-reported quality of life in 100 patients who underwent ultrafocal salvage HDR-brachytherapy.

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Patient-reported bowel symptoms were neglible.

•

Urinary complaints increased and sexual functioning declined over time.

•

Lower impact is predicted for patients with favorable function at baseline and lower dose to the urethra.

Purpose

For patients with a localized prostate cancer recurrence after radiotherapy, focal salvage treatment offers a less toxic alternative to whole-gland treatments, with the potential of preserving health-related quality of life (HR-QoL). With a focus on the patient’s perspective of treatment, this study aims to describe HR-QoL after ultrafocal salvage high-dose-rate brachytherapy (HDR-BT), and to explore predictive factors affecting HR-QoL.

Material and methods

We included 100 patients treated with ultrafocal salvage HDR-BT. Prostate cancer-related HR-QoL was assessed by the EORTC QLQ-PR25 questionnaire. Domains were urinary symptoms, bowel symptoms and sexual activity/functioning. For each domain, a mixed effects model was made to estimate HR-QoL trends over time. For domains showing clinically relevant change (≥10 points difference), the mixed effects model was used to explore potential predictors (age, baseline HR-QoL score, T-stage, tumor location, CTV size, dose to organs at risk and history of ADT).

Results

Median follow-up was 20 months (IQR 13–30). Mean questionnaire response rate was 86% (range 72–100%). Median baseline scores were 12 (urinary), 0 (bowel) and 67/50 (sexual activity/functioning). Urinary symptoms and sexual functioning showed clinically relevant deterioration over time (maximum difference of 11 and 12 points, respectively). Worse baseline score and higher administered dose to the urethra (≥16 Gy) were predictive of increased urinary symptoms (p < 0.01 and p = 0.03). Better baseline score was predictive of better sexual functioning (p < 0.01).

Conclusion

Ultrafocal salvage HDR-BT has negligible impact on bowel symptoms but does affect urinary symptoms and sexual functioning. Lower impact is predicted for patients with favorable urinary and sexual function at baseline. Urethral dose constraints should be closely monitored.

Salvage low dose rate brachytherapy for prostate cancer recurrence following definitive external beam radiation therapy

PURPOSE

We sought to describe the safety and efficacy of salvage low dose rate (LDR) brachytherapy for local prostate cancer recurrence following definitive RT.

MATERIALS AND METHODS

We included patients from two prospectively maintained institutional databases who underwent salvage LDR brachytherapy for biopsy confirmed intra-prostatic recurrence following primary RT. All patients were without evidence of metastatic disease. Freedom from biochemical failure (FFbF), prostate cancer specific survival (PCaSS), and overall survival (OS) were determined using the Kaplan-Meier estimates. Cox proportional hazard models were used to identify factors predictive of FFbF. Toxicity was graded by Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

RESULTS

108 patients were included. Median follow-up was 6.3 years. The 5- and 10-year actuarial survival outcomes were as follows: FFbF, 63.1% and 52.0%; PCaSS, 90.5% and 77.8%; OS, 80.9% and 56.7%. On multivariate modeling, increasing grade group (HR 1.41, 95% CI 1.02-1.95, p = 0.036) and initial PSA at diagnosis (HR 1.02, 95% CI 1.004-1.05, p = 0.022) were associated with worse FFbF. Grade 3 toxicity occurred in 16.7% of patients; including genitourinary events in 15.7% and gastrointestinal events in 2.8% of patients. IPSS scores increased following implant, peaking at 2 months (median IPSS 20, p = 0.002) and thereafter remaining elevated throughout follow-up.

CONCLUSIONS

Salvage LDR brachytherapy is safe and efficacious, with acceptable grade 3+ toxicity and good biochemical control on long-term follow-up. Patients with higher grade group and higher PSA at initial diagnosis may be at increased risk for biochemical failure.

Interim Results of a Prospective Prostate-Specific Membrane Antigen-Directed Focal Stereotactic Reirradiation Trial for Locally Recurrent Prostate Cancer

PURPOSE

To report the feasibility, toxicity, and preliminary outcomes (metabolic and biochemical) of ⁶⁸Ga-prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-directed focal prostate reirradiation using linear accelerator (LINAC)-based stereotactic body radiation treatment (SBRT).

METHODS AND MATERIALS

From March 2016 to March 2019, 25 patients were enrolled in a prospective single institution trial (ACTRN12617000035325). Eligibility criteria included patients with biopsy proven isolated prostate recurrence after definitive irradiation, with concordant multiparametric MRI and ⁶⁸Ga-PSMA PET/CT findings, and a prostate-specific antigen of less than 15 ng/mL at the time of recurrence. The study included a sequential dose escalation component with the first 18 patients receiving 36 Gy in 6 fractions on alternate days with subsequent patients receiving 38 Gy in 6 fractions assuming acceptable toxicity.

RESULTS

Median age was 72 years (range, 62-83) with a median time between first radiation treatment and salvage SBRT of 8.3 years (range, 4.5- 13.6). Median prostate-specific antigen at reirradiation was 4.1 (range, 1.1-16.6). The median follow-up was 25 months (range, 13-46). Acute grade 1 and 2 genitourinary (GU) toxicity occurred in 6 (24%) and 1 (4%) men, respectively. Acute grade 1 gastrointestinal (GI) toxicity occurred in 8% with one acute grade 3 GI toxicity (4%) due to a rectal ulcer overlying the hydrogel. Late grade 1 and 2 GU toxicity occurred in 28% and 4%. Late grade 1 GI toxicity occurred in 8% with no grade 2 or greater toxicity. Twenty-four patients have undergone per-protocol 12-month ⁶⁸Ga-PSMA PET/CT, of which 23 (92%) demonstrated a complete metabolic response. Biochemical freedom from failure was 80% at 2 years with 3 out of 4 of the biochemical failures exhibiting recurrent local disease.

CONCLUSIONS

PSMA-directed salvage focal reirradiation to the prostate using linear accelerator-based SBRT is feasible and safe. Toxicity was low, with very favorable short term local and biochemical control in a carefully selected cohort of patients.

Long-term results of a protocol-based ultrasound-guided salvage brachytherapy as re-irradiation for local recurrent prostate cancer

BACKGROUND AND PURPOSE

To assess the long-term results of protocol-based ultrasound-guided salvage pulsed-dose rate brachytherapy in locally recurrent prostate cancer following previous radiation therapy.

MATERIALS AND METHODS

A total of 82 patients (median age 69 years) with locally recurrent prostate cancer after previous external beam radiation therapy (43/82, 52.4%), prostatectomy and adjuvant radiation therapy (24/82, 29.3%) or brachytherapy (15/82, 18.3%) were treated with sole salvage interstitial pulsed-dose rate brachytherapy (PDR-BT). The treatment regimen consisted of two PDR-BT sections with 30 Gy (single pulse dose 0.6 Gy/h, 24 h per day) each up to a total reference dose of 60 Gy (EQD2 = 71.5 Gy-eq). The endpoints of the present analysis are cumulative local recurrence-rate, PSA-free survival, overall survival and the treatment-associated late toxicity according to the "Common Toxicity Criteria" with a median follow-up of 49 months (range, 12-129 months).

RESULTS

The 5-y. overall cumulative local recurrence rate was 17.7% with no significant differences between low, intermediate and high-risk groups. Differences in PSA-free survival were marginally non-significant, at 67.3%, 70.4% and 63.8% for low, intermediate and high risk group, respectively. No grade 3 gastrointestinal late side effects have been observed. The most common late side effect was urinary incontinence grade 1-3 and urinary frequency/urgency grade 1-3 in 18.3% (15/82) and 17.1% (14/82) of patients, respectively.

CONCLUSION

PDR salvage brachytherapy in local recurrent previously irradiated prostate cancer is efficient with low late toxicity. Salvage-brachytherapy represents a valuable therapeutic option for the treatment of previously irradiated locally recurrent prostate cancer.

PROLAPSE: survey about local prostate cancer relapse salvage treatment with external beam re-irradiation: results of the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

PURPOSE

We herein present the results of the first Italian Association of Radiotherapy and Clinical Oncology (AIRO) survey regarding salvage external beam re-irradiation of local prostate cancer relapse named PROLAPSE.

METHODS

A questionnaire with 12 items was administered to the 775 Italian radiation oncologist members of the AIRO.

RESULTS

One hundred of the members completed the survey. The survey highlighted that 59% of the participants are currently performing prostate re-EBRT, while nearly two-thirds (65%) affirmed that they are taking into consideration the procedure in case of intraprostatic relapse. Regarding the clinical target volume (CTV), only a minority (16%) declared to always prefer the partial prostate re-irradiation, while a consistent portion (nearly two-thirds) relied on clinical considerations of the choice towards partial or whole gland irradiation. The main techniques used for re-irradiation resulted to be intensity-modulated RT (IMRT)/volumetric modulated arc therapy (VMAT) and SBRT, having received approximately 40% of responses each. Regarding the criteria for patients' selection, more than 75% of responders agreed on the use of positron emission tomography (PET)/computed tomography (CT)-choline to exclude distant metastases and of multiparametric magnetic resonance imaging (mp-MRI) to detect intraprostatic recurrence. A sufficient timeframe (> 3 years) between primary RT and reirradiation was indicated by more than half of participants as an important driver in decision-making, while histological confirmation of the relapse was considered not essential by more than two-thirds. For the use of concomitant androgen deprivation therapy (ADT), most AIRO members (79%) agreed that the prescription should be based on a case-by-case analysis. Extreme hypofractionation (> 5 Gy/fraction) was preferred by the majority (52%) of the AIRO members. In most centers (more than 74%), the planning dose-volume constraints were generally extrapolated from the published data. In half of the cases, the interviewed responders affirmed that no major gastrointestinal (GI) and genitourinary (GU) toxicities were registered in the follow-up of their re-EBRT patients. Bladder complications represented the most commonly observed form of toxicity, with an incidence of 67%.

CONCLUSION

This first AIRO survey about salvage prostate re-EBRT provides an interesting snapshot and suggests increasing interest in re-EBRT patients in Italy. Consensus about some aspects of patients' selection, the necessity of biopsy, fractionation, and highly selective techniques seems feasible, but other key points such as irradiated volume, dosimetry parameters, and hormonal treatment association need to be clarified.

Diagnostic performance of imaging techniques for detecting of local recurrence after prostate brachytherapy

PURPOSE

The purpose of this study was to evaluate MRI and fluorocholine PET/CT diagnostic performances for the detection of local recurrence following prostate brachytherapy for localised prostate cancer.

MATERIAL AND METHODS

In this single-centre study, we retrospectively reviewed data from 21 patients treated by brachytherapy for localised prostate cancer and diagnosed with biochemical recurrence according to Phoenix Criteria, who underwent MRI and fluorocholine PET/CT. We included patients with local relapse suspicion according to imaging exams, with biopsy for the final assessment of local recurrence. Patient analysis data were supplemented by segment analysis using an 8-segment model.

RESULTS

The fluorocholine PET/CT was positive for 81% and negative for 19% of patients. The sensitivity and specificity were 92% and 33% with diagnosis accuracy of 67%. The MRI was positive for 57% and negative for 43% of patients. The sensitivity and specificity were 67% and 56% with diagnosis accuracy of 62%. There was no statistically significant difference between fluorocholine PET/CT and MRI accuracy (P=0.63). On a segment-based analysis, the sensitivity and specificity were 44% and 82% for fluorocholine PET/CT with diagnosis accuracy of 78%. For MRI, specificity was 91% diagnosis accuracy was 82%.

CONCLUSION

Both MRI and fluorocholine PET/CT permit to highlight local recurrence sites after prostate brachytherapy. Confirmation biopsies are, however, necessary since this accuracy is insufficient.

A Novel Salvage Option for Local Failure in Prostate Cancer, Reirradiation Using External Beam or Stereotactic Radiation Therapy: Systematic Review and Meta-Analysis

Purpose

Reirradiation (re-RT) using external beam radiation therapy (EBRT) is a novel salvage strategy for local failure in prostate cancer. We performed a systematic review describing oncologic and toxicity outcomes for salvage EBRT/stereotactic radiation therapy (SBRT) re-RT.

Methods and Materials

A International Prospective Register of Systematic Reviews registered (#141466) systematic review, meta-analysis, and meta-regression was conducted using preferred reporting items for systematic reviews and meta-analyses guidelines. PubMed and EMBASE were searched from inception through September 2019. Outcome measures included local control (LC), biochemical relapse free survival (BRFS), and ≥grade 3 genitourinary (GU)/gastrointestinal (GI) toxicity. EBRT and SBRT data were collected separately. Meta-regression explored disease and toxicity outcomes as a function of equivalent dose in 2 Gy fractions (EQD2), length of follow-up, and partial versus whole prostate reirradiation.

Results

Nineteen studies representing 13 cohorts were included (428 patients). Weighted mean follow-up was 26.1 months. Median re-RT EQD2 was 77.1 Gy (α/β = 1.5), with 92% of patients receiving SBRT, 52.1% of patients receiving partial prostate re-RT, and 30.1% of patients receiving androgen deprivation therapy with re-RT. LC was 83.2% (95% confidence interval [CI], 75.5%-90.9%) and BRFS was 59.3% (47.9%-70.7%). Reported late toxicity ≥grade 3 was 3.4% (95% CI, 1.0%-5.8%) for GU and 2.0% (95% CI, 0.1%-4.0%) for GI. Meta-regression found higher LC, BRFS, and reported GU/GI toxicity with increasing EQD2, with partial prostate re-RT associated with less reported GU/GI toxicity and no detriment to LC and BRFS.

Conclusions

Salvage re-RT using EBRT, particularly with SBRT, is an emerging technique to treat isolated local failure of prostate cancer. With short-term follow-up, LC, BRFS, and reported toxicities appear reasonable, although further follow-up is required before definitive statements on late toxicities can be made. Our review is limited by incomplete reporting of androgen deprivation therapy use in the primary literature. Further prospective studies and longer follow-up are needed before considering re-RT as standard practice.

Efficacy and toxicity outcomes for patients treated with focal salvage high dose rate brachytherapy for locally recurrent prostate cancer

•

Local recurrence of prostate cancer may be treated with salvage therapies.

•

Focal salvage high dose rate brachytherapy provides good biochemical control.

•

Severe genitourinary and gastrointestinal toxicities are low.

Introduction

Isolated local recurrence of prostate cancer following primary radiotherapy or brachytherapy may be treated with focal salvage high dose rate brachytherapy, although there remains an absence of high quality evidence to support this approach.

Methods

Men with prostate cancer treated consecutively between 2015 and 2018 using 19 Gy in a single fraction high dose rate brachytherapy (HDR) for locally recurrent prostate cancer were identified from an institutional database. Univariable analysis was performed to evaluate the relationship between patient, disease and treatment factors with biochemical progression free survival (bPFS).

Results

43 patients were eligible for evaluation. Median follow up duration was 26 months (range 1–60). Median bPFS was 35 months (95% confidence interval 25.6–44.4). Kaplan-Meier estimates for bPFS at 1, 2 and 3 years post salvage were 95.2%, 70.6% and 41.8% respectively. On univariable Cox regression analysis, only nadir PSA was significantly associated with bPFS although the majority of patients were also treated with androgen deprivation therapy. Only one late grade 3 genitourinary toxicity was observed.

Conclusion

Focal salvage HDR brachytherapy may provide good biochemical control with a low risk of severe toxicity. Further evaluation within clinical trials are needed to establish its role in the management of locally recurrent prostate cancer.

A Prospective Study of 18F-DCFPyL PSMA PET/CT Restaging in Recurrent Prostate Cancer following Primary External Beam Radiotherapy or Brachytherapy

PURPOSE

Radio-recurrent prostate cancer is typically detected by a rising prostate-specific antigen and may reflect local or distant disease. Positron emission tomography (PET) radiotracers targeting prostate-specific membrane antigen, such as 18F-DCFPyL have shown promise in restaging men with recurrent disease postprostatectomy but are less well characterized in the setting of radio-recurrent disease.

METHODS AND MATERIALS

A prospective, multi-institutional study was conducted to evaluate the effect of 18F-DCFPyL PET/computed tomography (CT) when added to diagnostic imaging (DI; CT abdomen and pelvis, bone scan, multiparametric magnetic resonance imaging pelvis) for men with radio-recurrent prostate cancer. All men were imaged with DI and subsequently underwent 18F-DCFPyL PET/CT with local and central reads. Tie break reads were performed as required. Management questionnaires were completed after DI and again after 18F-DCFPyL PET/CT. Discordance in patterns of disease detected with 18F-DCFPyL PET/CT versus DI and changes in management were characterized.

RESULTS

Seventy-nine men completed the study. Most men had T1 disease (62%) and Gleason score <7 (95%). Median prostate-specific antigen at diagnosis was 7.4 ng/mL and at relapse was 4.8 ng/mL. DI detected isolated intraprostatic recurrence in 38 out of 79 men (48%), regional nodal recurrence in 9 out of 79 (11%), distant disease in 12 out of 79 (15%), and no disease in 26 out of 79 (33%). 18F-DCFPyL PET/CT detected isolated intraprostatic recurrence in 38 out of 79 men (48%), regional nodal recurrence in 21 out of 79 (27%), distant disease in 24 out of 79 (30%), and no disease in 10 out of 79 (13%). DI identified 8 out of 79 (10%) patients to have oligometastatic disease, compared with 21 out of 79 (27%) with 18F-DCFPyL PET/CT. 18F-DCFPyL PET/CT changed proposed management in 34 out of 79 (43%) patients.

CONCLUSIONS

18F-DCFPyL PET/CT identified extraprostatic disease in twice as many men with radio-recurrent prostate cancer compared with DI and detected a site of recurrence in 87% of men compared with 67% with DI. Furthermore, 18F-DCFPyL PET/CT identified potentially actionable disease (prostate only recurrence or oligometastatic disease) in 75% of men and changed proposed management in 43% of men.

[The radiation oncologist, one of the actors in the patient's path after cancer. Follow up after prostate cancer]

Prostate cancer is the most common cancer of men over 50 years old. Localized prostatic cancer treatment may be responsible of a decline of patient's quality of life. The main actors of treatment are now focused on minimizing functional consequences of treatments. The radiation oncologist has a central role in patient monitoring. The follow-up is codified by official recommendations of learned societies to enhance the post-cancer period. The main objective of this article is to review the recommendations for clinical and biological follow-up. An inventory of the functional consequences of the various treatments will be detailed, and particularly those caused by androgen deprivation therapy, with a review of precautions before implementation, adverse effects and their management, as well as monitoring recommendations. The analysis of quality of life after curative treatment and suggestions to improve monitoring will also be discussed.

Salvage high-intensity focused ultrasound for locally recurrent prostate cancer after low-dose-rate brachytherapy: oncological and functional outcomes

OBJECTIVES

To evaluate the oncological and functional outcomes of salvage high-intensity focused ultrasound (S-HIFU) for locally recurrent prostate cancer after low-dose-rate (LDR) brachytherapy.

PATIENTS AND METHODS

Clinical phase II studies (2003-2015) included 50 consecutive patients with post-brachytherapy local recurrence treated by S-HIFU. S-HIFU was performed with post-external beam radiotherapy (EBRT) parameters and, since 2008, with specific post-brachytherapy parameters. Treatments were whole-gland ablation and, since 2009, hemi-ablation in cases of unilateral prostate cancer. The primary objective was to assess oncological outcomes: treatment failure-free survival, progression-free survival (PFS), overall survival (OS), cancer-specific survival (CSS), and metastasis-free survival (MFS) rates. The secondary objective was to evaluate adverse events, continence, and erectile function. Kaplan-Meier analysis estimated oncological outcomes.

RESULTS

In all, 13 patients were treated with post-EBRT parameters, 37 with post-brachytherapy parameters, 35 with whole-gland treatment, and 15 with hemi-ablation. The median follow-up was 4.6 years. After S-HIFU, the median prostate-specific antigen level was 0.3 ng/mL. At 6 years, treatment failure-free survival, PFS, OS, CSS, and MFS rates were 41%, 45%, 93%, 98%, and 80%, respectively. Post-brachytherapy compared with post-EBRT parameters reduced Grade 2-3 incontinence (34% vs 62%, P = 0.015). Incontinence, bladder outlet obstruction and Grade ≥III complications were significantly reduced with hemi-ablation compared with whole-gland treatment (14% vs 54%, P < 0.001; 13% vs 46%, P = 0.03; 13% vs 63%, P = 0.001; respectively). Before S-HIFU, 25 patients had a five-item version of the International Index of Erectile Function score of ≥17, which was maintained in 48% at 12 months.

CONCLUSION

S-HIFU for locally recurrent prostate cancer after LDR brachytherapy is associated with favourable survival rates at a price of significant morbidity. Dedicated post-brachytherapy parameters and hemi-ablation improve the safety of the treatment.

A review of salvage treatment options for disease progression after radiation therapy for localized prostate cancer

Recurrence of prostate cancer after initial treatment with radiation therapy (RT) is highly dependent on pretreatment risk group and unfortunately, a proportion of patients fail primary treatment. The treatment of recurrence after primary radiation is rapidly changing with advances in imaging and it is important to distinguish those with a local failure from those with distant failure. If disease remains locally confined, salvage treatment with a variety of techniques can still provide a potential cure. Patients with distant failure are often treated with androgen deprivation, or in those with a shorter life expectancy, conservative management. In patients with a higher burden of metastatic disease, there is emerging evidence that chemotherapy and advanced androgen therapy can improve survival. We review the relevant literature on available salvage treatment options and appropriate patient selection for patients with recurrent prostate cancer after RT. We report on the efficacy and adverse effects of the currently available local salvage modalities including salvage radical prostatectomy, high dose rate and low dose rate brachytherapy, cryotherapy, high intensity focused ultrasound, and stereotactic body RT. We additionally discuss diagnosis of oligometastatic disease on imaging and current approaches to treatment with either radiation or surgery. While a full review of chemotherapy and advanced androgen therapies is beyond the scope of this article we briefly discuss their use in the treatment of newly diagnosed recurrence after radiation.

Salvage high-intensity focused ultrasound versus salvage radical prostatectomy for radiation-recurrent prostate cancer: a comparative study of oncological, functional, and toxicity outcomes

PURPOSE

To compare oncological, functional, and toxicity outcomes of patients with radiation-recurrent prostate cancer (PCa) after external beam radiation therapy (EBRT) or brachytherapy (BT) treated with salvage high-intensity focused ultrasound (S-HIFU) or salvage radical prostatectomy (S-RP).

METHODS

This retrospective study compared 52 patients with radiation-recurrent PCa after EBRT or BT treated with S-HIFU (n = 27) or S-RP (n = 25) between 1998 and 2016. We estimated overall survival (OS), cancer-specific survival (CSS), and metastasis-free survival (MFS) at 5 years. Incontinence after local salvage therapy (LST) was scored according to the number of pads used per day. Complications were graded according to the Clavien-Dindo classification.

RESULTS

Both groups were similar for pre-LST tumor features, however, no S-HIFU patients received BT and S-RP patients were younger and healthier. Median follow-up was 45 months for S-HIFU and 43 months for S-RP. No significant differences were found in estimated 5-year OS (80.9% vs. 61.9%, p = 0.24), 5-year CSS (84.0% vs. 74.0%, p = 0.36), and 5-year MFS (60.3% vs. 55.2%, p = 0.55) for S-HIFU vs. S-RP, respectively. We observed a significant difference in pad-dependent status at 12 months (22.2% vs. 56.0%, p = 0.01) and in the number of Clavien ≥ III complications [9 (7/27 patients) vs. 16 (12/25 patients), p = 0.027] in favor of S-HIFU vs. S-RP, respectively.

CONCLUSION

S-HIFU and S-RP could both be considered valuable LST options for patients with radiation-recurrent nonmetastatic PCa with sufficient life expectancy. S-RP is associated with more pad-dependent patients at 12 months.

Salvage CyberKnife-Based Reirradiation of Patients With Recurrent Prostate Cancer: The Single-Center Experience

The aim of this study was to evaluate CyberKnife-based radioablation as a salvage treatment for prostate cancer postirradiation relapses based on a group of patients disqualified from available conventional methods of salvage treatment. Thirty-eight patients were treated with a fraction dose varying from 5.5 to 10 Gy (median 7.35) to a total dose of 18 to 36.25 Gy (median 36.25). In all, 55.3% of patients had androgen deprivation therapy during this time. Nine patients had oligometastases in the salvage time. The follow-up varied from 1.6 to 46.4 months (mean 19.7, median 14.4). In all, 92.6% to 97.4% of patients had no gastrointestinal acute adverse effects; no effects higher than G1 were noted. There were particular (up to 4.8%) G2 late gastrointestinal effects. The percentage without genitourinary acute effects varied from 59.1% to 78.9%; 3.7% had G3 toxicity. G3 late genitourinary toxicity appeared 3 times, the maximal percentage being 12.5% (24 months after salvage treatment). The nadir of prostate-specific antigen median was 0.24 ng/mL (9 months after treatment). Twelve (31.6%) patients failed in the timeline of 6 to 42 months after salvage treatment (mean 18.7, median 16.5)—5 due to dissemination. In 2 cases, progression in existing metastases was identified. Five (13.2%) patients had biochemical failure without additional metastases (local relapses); hence, local control was 86.8%. The failure risk is strongly influenced by initial disease stage and presalvage prostate-specific antigen concentration. The obtained results permit us to conclude that such a treatment could be an effective and safe option for prostate cancer postirradiation relapse salvage treatment.

Focal Salvage Treatment of Radiorecurrent Prostate Cancer: A Narrative Review of Current Strategies and Future Perspectives

Over the last decades, primary prostate cancer radiotherapy saw improving developments, such as more conformal dose administration and hypofractionated treatment regimens. Still, prostate cancer recurrences after whole-gland radiotherapy remain common, especially in patients with intermediate- to high-risk disease. The vast majority of these patients are treated palliatively with androgen deprivation therapy (ADT), which exposes them to harmful side-effects and is only effective for a limited amount of time. For patients with a localized recurrent tumor and no signs of metastatic disease, local treatment with curative intent seems more rational. However, whole-gland salvage treatments such as salvage radiotherapy or salvage prostatectomy are associated with significant toxicity and are, therefore, uncommonly performed. Treatments that are solely aimed at the recurrent tumor itself, thereby better sparing the surrounding organs at risk, potentially provide a safer salvage treatment option in terms of toxicity. To achieve such tumor-targeted treatment, imaging developments have made it possible to better exclude metastatic disease and accurately discriminate the tumor. Currently, focal salvage treatment is being performed with different modalities, including brachytherapy, cryotherapy, high-intensity focused ultrasound (HIFU), and stereotactic body radiation therapy (SBRT). Oncologic outcomes seem comparable to whole-gland salvage series, but with much lower toxicity rates. In terms of oncologic control, these results will improve further with better understanding of patient selection. Other developments, such as high-field diagnostic MRI and live adaptive MRI-guided radiotherapy, will further improve precision of the treatment.