A systematic review of salvage focal therapies for localised non-metastatic radiorecurrent prostate cancer

Abstract

Although radiotherapy to the prostate for cancer is effective, recurrence occurs in 10-15% within 5 years. Traditional salvage treatments for men with radiorecurrent prostate cancer comprise of watchful waiting (WW) with or without androgen deprivation therapy (ADT) or radical prostatectomy (RP). Neither strategy provides ideal therapeutic ratios. Salvage focal ablation is an emerging option. We performed a systematic review of the Medline and Embase databases for studies reporting outcomes of focal salvage brachytherapy (sBT), cryotherapy (sCT) or high-intensity focused ultrasound (sHIFU) for radiorecurrent prostate cancer (conception to April 2019). Results were screened for inclusion against predetermined eligibility criteria. Certain data were extracted, including rates of biochemical disease-free survival (BDFS), metastasis, conversion to second-line therapies and adverse events. Of a total 134 articles returned from the search, 15 studies (14 case series and 1 comparative study) reported outcomes after focal sBT [5], sCT[7] and sHIFU [3]. Cohort size varied depending on intervention, with eligible studies of sBT being small case series. Median follow-up ranged from 10 to 56 months. Although pre-salvage demographics were similar [median age range, 61-75 years; prostate-specific antigen (PSA) range, 2.8-5.5 ng/mL], there was heterogeneity in patient selection, individual treatment protocols and outcome reporting. At 3 years, BDFS ranged from 61% to 71.4% after sBT, 48.1-72.4% after sCT and 48% after sHIFU. Only studies of sCT reported 5-year BDFS, which ranged from 46.5% to 54.4%. Rates of metastasis were low after all salvage modalities, as were conversion to second-line therapies (although this was poorly reported). Grade 3 adverse events were rare. This systematic review indicates that salvage focal ablation of radiorecurrent prostate cancer provides acceptable oncological outcomes and is well tolerated. Unfortunately, there is heterogeneity in the study design of existing evidence. Level 1 research comparing salvage focal therapies to existing wholegland strategies is needed to further establish the role of these promising treatments.

Focal Therapy for Prostate Cancer: Complications and Their Treatment

“…A recent systematic review by Khoo et al has summarized the complication rates for focal therapy strategies performed after ERBT treatment ( 36 ). Grade 3 toxicity adverse events were rare with all treatment modalities: recto-urethral fistula was reported in 0–5.5%, urethral stricture in 5–10% and pubic bone osteitis in 0.7–4.2%.…”

Development and internal validation of multivariable prediction models for biochemical failure after MRI-guided focal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer

“…In this setting, focal therapy, targeting the recurrent lesion while sparing healthy prostate tissue, is an attractive treatment option with the aim of postponing initiation of androgen deprivation therapy (ADT) [5,8]. The main potential advantage of focal over whole-gland salvage treatments is the reduced chance of side-effects and quality of life deterioration, without affecting oncological outcomes [9][10][11][12][13][14][15].…”

The clinical guiding value of a radiomics model for androgen deprivation therapy for prostate cancer

“…Therefore, our hypothesis was that the extracted radiomics features from MR images can reflect the tissue pathological changes after ADT and that the features can be used to guide clinical treatment (adding antiandrogen intensive therapy or intensifying focal therapy). 12 In this study, first, we evaluated the value of a clinical model, radiomics model and combined model after ADT in the ADT non-responder group to provide clinical guidance and to differentiate residual lesions from the peripheral zone (PZ) and central gland (CG) to lay the foundation for focal therapy. Second, we attempted to verify whether a combined model is more helpful to determine the next treatment.…”

“…Therefore, our hypothesis was that the extracted radiomics features from MR images can reflect the tissue pathological changes after ADT and that the features can be used to guide clinical treatment (adding antiandrogen intensive therapy or intensifying focal therapy). 12…”