title: Focal salvage high-intensity focused ultrasound in radiorecurrent prostate cancer.
abstract: To assess short- to medium-term cancer control rates and side effects of focal salvage high- intensity focused ultrasound (HIFU).
  
  
  
  A retrospective registry analysis identified 150 men who underwent focal salvage HIFU (FS-HIFU) (Sonablate 500) between November 2006 and August 2015. Metastatic disease was excluded by nodal assessment on the pelvic MRI, a radioisotope bone scan and positron-emission tomography (PET) imaging (choline-18F-fluorodeoxyglucose PET or choline PET-CT). In our current clinical practice, metastatic disease must be excluded by both choline PET and bone scan. Localization of cancer was carried out using multiparametric MRI of the prostate (T2-weighted, diffusion-weighted and dynamic contrast-enhanced imaging) with systematic or template prostate mapping biopsies. The primary outcome was a composite failure incorporating biochemical failure (BCF) and/or positive localized or distant imaging results and/or positive biopsy and/or systemic therapy and/or metastases/prostate cancer-specific death. The secondary outcome was BCF using the Phoenix-ASTRO definition (prostate-specific antigen [PSA] nadir + 2 ng/mL). We used Kaplan-Meier analysis and Cox proportional hazards regression to quantify the effect of the determinants on the endpoints.
  
  
  
  The mean (standard deviation [sd]) patient age at focal salvage HIFU was 69.8 (6.1) years and the median (interquartile range [IQR]) PSA pre-focal salvage HIFU was 5.5 (3.6-7.9) ng/mL. The median (IQR) follow-up was 35 (22-52) months. Patients were classified as having low- 2.7% (4/150), intermediate- 39.3% (59/150) and high-risk disease 41.3% (62/150) according to D'Amico classification, prior to focal salvage HIFU. Composite failure occurred in 61% of patients (91/150) and BCF occurred in 51.3% (77/150). The Kaplan-Meier composite endpoint-free survival (CEFS) rate at 3 years was 40% (95% confidence interval [CI] 31-50) for the entire group. Kaplan-Meier estimates of CEFS were 100%, 49% and 24% at 3 years in the low-, intermediate- and high-risk groups pre-salvage HIFU, respectively. The Kaplan-Meier biochemical disease-free survival (BDFS) rate at 3 years was 48% (95% CI 39-59) for the entire group. Kaplan-Meier estimates of BDFS were 100%, 61% and 32% at 3 years in the low-, intermediate- and high-risk groups pre-salvage HIFU, respectively. Complications included urinary tract infection (11.3%; 17/150), bladder neck stricture (8%; 12/150), recto-urethral fistula after one HIFU procedure (2%; 3/150) and osteitis pubis (0.7%; 1/150).
  
  
  
  Focal salvage HIFU conferred a relatively low complication and side effect rate. CEFS and biochemical control in the short to medium term were reasonable, especially in this relatively high-risk cohort, but still low compared with current whole-gland salvage therapies. Focal salvage therapy may offer disease control in men at high risk whilst minimizing additional treatment morbidities.
authors.affiliation: Division of Surgery and Interventional Science, University College London, London, UK.|Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Abi
authors.identifier: 0000-0003-1599-2455
authors.initials: A
authors.lastname: Kanthabalan
authors.affiliation: Department of Radiation Oncology, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Max
authors.identifier: 0000-0002-7981-5768
authors.initials: M
authors.lastname: Peters
authors.affiliation: Department of Radiation Oncology, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Marco
authors.initials: M
authors.lastname: Van Vulpen
authors.affiliation: Division of Surgery and Interventional Science, University College London, London, UK.|Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: McCartan
authors.affiliation: Department of Urology, Hampshire Hospitals NHS Foundation Trust, Basingstoke, UK.
authors.forename: Richard Graham
authors.initials: RG
authors.lastname: Hindley
authors.affiliation: Department of Urology, Hampshire Hospitals NHS Foundation Trust, Basingstoke, UK.
authors.forename: Amr
authors.initials: A
authors.lastname: Emara
authors.affiliation: Division of Surgery and Interventional Science, University College London, London, UK.|Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Moore
authors.affiliation: Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Manit
authors.initials: M
authors.lastname: Arya
authors.affiliation: Division of Surgery and Interventional Science, University College London, London, UK.|Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Emberton
authors.affiliation: Division of Surgery and Interventional Science, University College London, London, UK.|Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK.|Division of Surgery, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK.
authors.forename: Hashim Uddin
authors.initials: HU
authors.lastname: Ahmed
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000628:therapy*; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy / Q000628:therapy*; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000379:methods*; D016896:Treatment Outcome; D036761:Ultrasound, High-Intensity Focused, Transrectal / Q000009:adverse effects
keywords: focal salvage HIFU; radiorecurrent prostate cancer