Oligometastases from prostate cancer: local treatment with stereotactic body radiotherapy (SBRT)

Abstract

BackgroundThe impact of local tumor ablative therapy in oligometastasized prostate cancer (PC) is still under debate. To gain data for this approach, we evaluated oligometastasized PC patients receiving stereotactic body radiotherapy (SBRT) to bone metastases.MethodsIn this retrospective study, 15 oligometastasized PC patients with a total of 20 bone metastases were evaluated regarding biochemical progression-free survival (PSA-PFS), time to initiation of ADT, and local control rate (LCR). Three patients received concomitant androgen deprivation therapy (ADT).ResultsThe median follow-up after RT was 22.5 months (range 7.0–53.7 months). The median PSA-PFS was 6.9 months (range 1.1–28.4 months). All patients showing a decrease of PSA level after RT of at least factor 10 reveal a PSA-PFS of >12 months. Median PSA-PFS of this sub-group was 23.1 months (range 12.1–28.4 months). Local PFS (LPFS) after 2 years was 100%. One patient developed a local failure after 28.4 months. Median distant PFS (DPFS) was 7.36 months (range 1.74–54.34 months). The time to initiation of ADT in patients treated without ADT was 9.3 months (range 2.6–36.1 months). In all patients, the time to intensification of systemic therapy or the time to initiation of ADT increased from 9.3 to 12.3 months (range 2.6–36.1 months). Gleason-Score, ADT or the localization of metastasis had no impact on PFS or time to intensification of systemic therapy. No SBRT related acute or late toxicities were observed.ConclusionOur study shows that SBRT of bone metastases is a highly effective therapy with an excellent risk-benefit profile. However, PFS was limited due to a high distant failure rate implying the difficulty for patient selection for this oligometastatic concept. SBRT offers high local cancer control rates in bone oligometastases of PC and should be evaluated with the aim of curation or to delay modification of systemic treatment.

The efficacy of Stereotactic body radiation therapy and the impact of systemic treatments in oligometastatic patients from prostate cancer

“…High local control rates are reported in literature in this setting. Ahmed et al and Habl et al, observed a similar 100% of local control when treating 17 and 15 patients respectively. Muacevic et al .…”

“…Our results are consistent with those published by other authors. For example Habl et al reported that ADT had no impact on PFS, time to initiation of ADT, or to intensification of systemic therapy. Also Jereczek‐fossa et al demonstrated that time to progression after SBRT for nodal metastases was similar whether androgen deprivation was added or not (11 vs 10 months).…”

Use of stereotactic body radiation therapy for oligometastatic recurrent prostate cancer: A systematic review

“…The exclusion reasons with references are listed in Data S2. Finally, 14 articles were selected for data extraction and subsequent qualitative synthesis.…”

“…One randomized controlled trial was found, but it did not meet all the eligibility criteria, so it was not included in the qualitative analysis . Thirteen articles were single‐arm case series/cohort studies, and one case–control series, with five (36%) prospective and nine (64%) retrospective researches . Median follow‐up period varied from 10.2 to 36.6 months (Table ).…”

“…Choline PET/CT was the most commonly used evaluation method and was present in all the studies . However, six of them allowed its substitution for less accurate tests (18F‐FDG PET/CT, MRI, CT and/or Bone Scan) in a minority of patients (<5%).…”