title: Progression-free Survival Following Stereotactic Body Radiotherapy for Oligometastatic Prostate Cancer Treatment-naive Recurrence: A Multi-institutional Analysis.
abstract: The literature on metastasis-directed therapy for oligometastatic prostate cancer (PCa) recurrence consists of small heterogeneous studies. This study aimed to reduce the heterogeneity by pooling individual patient data from different institutions treating oligometastatic PCa recurrence with stereotactic body radiotherapy (SBRT). We focussed on patients who were treatment naive, with the aim of determining if SBRT could delay disease progression. We included patients with three or fewer metastases. The Kaplan-Meier method was used to estimate distant progression-free survival (DPFS) and local progression-free survival (LPFS). Toxicity was scored using the Common Terminology Criteria for Adverse Events. In total, 163 metastases were treated in 119 patients. The median DPFS was 21 mo (95% confidence interval, 15-26 mo). A lower radiotherapy dose predicted a higher local recurrence rate with a 3-yr LPFS of 79% for patients treated with a biologically effective dose ≤100Gy versus 99% for patients treated with >100Gy (p=0.01). Seventeen patients (14%) developed toxicity classified as grade 1, and three patients (3%) developed grade 2 toxicity. No grade ≥3 toxicity occurred. These results should serve as a benchmark for future prospective trials.
  
  
  RESULTS
  This multi-institutional study pools all of the available data on the use of stereotactic body radiotherapy for limited prostate cancer metastases. We concluded that this approach is safe and associated with a prolonged treatment progression-free survival.
authors.affiliation: Department of Radiotherapy, Ghent University Hospital, Belgium. Electronic address: piet.ost@ugent.be.
authors.forename: Piet
authors.initials: P
authors.lastname: Ost
authors.affiliation: University of Milan and European Institute of Oncology, Milan Italy.
authors.forename: Barbara Alicja
authors.initials: BA
authors.lastname: Jereczek-Fossa
authors.affiliation: Department of Radiotherapy Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Nicholas Van
authors.initials: NV
authors.lastname: As
authors.affiliation: Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zilli
authors.affiliation: Cyberknife Center Munich Grosshadern, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Muacevic
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Olivier
authors.affiliation: Department of Radiotherapy Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Henderson
authors.affiliation: Ecomedica Radioterapia, Empoli, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Casamassima
authors.affiliation: University of Milan and European Institute of Oncology, Milan Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Orecchia
authors.affiliation: University of Milan and European Institute of Oncology, Milan Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Surgo
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Brown
authors.affiliation: Department of Radiotherapy Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Tree
authors.affiliation: Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Raymond
authors.initials: R
authors.lastname: Miralbell
authors.affiliation: Department of Radiotherapy, Ghent University Hospital, Belgium.
authors.forename: Gert
authors.initials: G
authors.lastname: De Meerleer
mesh_terms: D000008:Abdominal Neoplasms / Q000188:drug therapy / Q000556:secondary / Q000601:surgery*; D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy / Q000556:secondary / Q000601:surgery*; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D000726:Androgen Antagonists; D000970:Antineoplastic Agents
keywords: Neoplasm metastasis; Neoplasm recurrence; Oligometastasis; Prostatic neoplasms; Radiosurgery; Stereotactic body radiotherapy