Toxicity and Efficacy of Local Ablative, Image-guided Radiotherapy in Gallium-68 Prostate-specific Membrane Antigen Targeted Positron Emission Tomography-staged, Castration-sensitive Oligometastatic Prostate Cancer: The OLI-P Phase 2 Clinical Trial

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Tobias Hölscher - , University Hospital Carl Gustav Carus Dresden (Author)
  • Michael Baumann - , OncoRay ZIC - National Center for Radiation Research in Oncology (Partners: UKD, HZDR), German Cancer Research Center (DKFZ), SRH University Heidelberg, University Hospital Carl Gustav Carus Dresden (Author)
  • Jörg Kotzerke - , German Center for Neurodegenerative Diseases, Dresden site (Partner: DZNE of the Helmholtz Association), National Center for Tumor Diseases (NCT) Heidelberg, German Cancer Research Center (DKFZ), SRH University Heidelberg, University Hospital Carl Gustav Carus Dresden (Author)
  • Klaus Zöphel - , University Hospital Carl Gustav Carus Dresden (Author)
  • Frank Paulsen - , University Hospital Tübingen (Author)
  • Arndt-Christian Müller - , University Hospital Heidelberg (Author)
  • Daniel Zips - , University Hospital Tübingen (Author)
  • Lydia Koi - , University Hospital Carl Gustav Carus Dresden (Author)
  • Christian Thomas - , German Center for Neurodegenerative Diseases, Dresden site (Partner: DZNE of the Helmholtz Association), National Center for Tumor Diseases (NCT) Heidelberg, German Cancer Research Center (DKFZ), SRH University Heidelberg, University Hospital Carl Gustav Carus Dresden (Author)
  • Steffen Löck - , University Hospital Carl Gustav Carus Dresden (Author)
  • Mechthild Krause - , University Hospital Carl Gustav Carus Dresden (Author)
  • Manfred Wirth - , University Hospital Carl Gustav Carus Dresden (Author)
  • Fabian Lohaus - , University Hospital Carl Gustav Carus Dresden (Author)

Abstract

BACKGROUND: Local ablative radiotherapy (aRT) of oligometastatic prostate cancer (PCa) is very promising and has become a focus of current clinical research.

OBJECTIVE: We hypothesize that aRT is safe and effective in gallium-68 prostate-specific membrane antigen targeted positron emission tomography (PSMA-PET)-staged oligometastatic PCa patients.

DESIGN, SETTING, AND PARTICIPANTS: A nonrandomized, prospective, investigator-initiated phase 2 trial recruited patients with oligometastatic PCa (five or fewer lymph node or osseous metastases) after local curative therapy, without significant comorbidity and androgen deprivation therapy (ADT), at two German centers from 2014 to 2018.

INTERVENTION: All PSMA-PET-positive metastases were treated with aRT. No systemic therapy was initiated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was treatment-related toxicity (grade ≥2) 24 mo after aRT. A one-sided single-sample test of proportions was planned to test whether the endpoint occurs in <15% of the patients. Key secondary endpoints were time to progression of prostate-specific antigen (PSA) and time to ADT, which were associated with potential prognostic factors by Cox regression.

RESULTS AND LIMITATIONS: Of 72 patients, 63 received aRT (13% dropout rate). The median follow-up was 37.2 mo. No treatment-related grade ≥2 toxicity was observed 2 yr after treatment. The median time to PSA progression and time to ADT were 13.2 and 20.6 mo, respectively. Of the patients, 21.4% were free of PSA progression after 3 yr.

CONCLUSIONS: It was observed that aRT is safe, and midterm PSA progression and ADT-free time were achieved in one of five patients. Randomized clinical trials are indicated to further evaluate the option of delaying ADT in selected patients.

PATIENT SUMMARY: In this clinical trial, 63 patients with up to five metastases of prostate cancer without androgen deprivation therapy were included. We showed that local ablative radiotherapy is safe and that one in five patients had no recurrent prostate-specific antigen value after 3 yr. Local ablative radiotherapy might be an option to avoid systemic therapy in selected patients.

Details

Original languageEnglish
JournalEuropean urology oncology
Publication statusE-pub ahead of print - 13 Nov 2021
Peer-reviewedYes

External IDs

Scopus 85123639036
ORCID /0000-0002-7017-3738/work/142253927

Keywords

Sustainable Development Goals