Predictors for post-treatment biopsy outcomes after prostate stereotactic body radiotherapy Journal Article


Authors: Zelefsky, M. J.; Goldman, D. A.; Hopkins, M.; Pinitpatcharalert, A.; McBride, S.; Gorovets, D.; Ehdaie, B.; Fine, S. W.; Reuter, V. E.; Tyagi, N.; Happersett, L.; Teyateeti, A.; Zhang, Z.; Kollmeier, M. A.
Article Title: Predictors for post-treatment biopsy outcomes after prostate stereotactic body radiotherapy
Abstract: Purpose: To investigate predictors associated with post-treatment biopsy outcomes after stereotactic body radiotherapy (SBRT) for localized prostate cancer. Materials and methods: 257 patients treated with prostate SBRT to dose levels of 32.5 Gy to >40 Gy in 5–6 fractions underwent a post-treatment biopsy performed approximately two years after treatment to evaluate local control status. 73 had% intermediate-risk disease (n = 187) and the remaining 17% (n = 43) and 10% (n = 27) had low-risk and high-risk disease, respectively. Results: The incidence of positive, negative, and treatment-effect post-treatment biopsies were 15.6%, 57.6%, and 26.8%, respectively. The incidence of a positive biopsy according to dose was 37.5% (n = 9/24), 21.4% (n = 6/28), 19.4% (n = 6/31), and 10.9% (n = 19/174) for 32.5 Gy, 35 Gy, 37.5 Gy, and >40 Gy, respectively. In a multivariable model, patients treated with SBRT doses of <40 Gy and those with unfavorable-intermediate-risk or high-risk disease had higher likelihood of a positive post-treatment biopsy. A positive post-SBRT biopsy was associated with a significantly higher likelihood of subsequent PSA relapse at five years (Positive biopsy: 57%, 95% CI: 29–77% compared to negative biopsy: 7%, 95% CI: 3–14%; p < 0.001). Conclusion: Based on two-year post-SBRT biopsies, excellent tumor control was achieved when dose levels of 40 Gy or higher were used. Standard SBRT dose levels of 35–37.5 Gy were associated with a higher likelihood of a positive post-treatment biopsy. Two-year positive post-treatment biopsies pre-dated the development of PSA failure in the majority of patients. © 2021 Elsevier B.V.
Keywords: stereotactic body radiotherapy; localized prostate cancer; predictive factors; post-treatment biopsy
Journal Title: Radiotherapy and Oncology
Volume: 159
ISSN: 0167-8140
Publisher: Elsevier Inc.  
Date Published: 2021-06-01
Start Page: 33
End Page: 38
Language: English
DOI: 10.1016/j.radonc.2021.02.008
PUBMED: 33587971
PROVIDER: scopus
PMCID: PMC10187562
DOI/URL:
Notes: Article -- Export Date: 3 May 2021 -- Source: Scopus
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MSK Authors
  1. Zhigang Zhang
    392 Zhang
  2. Michael J Zelefsky
    749 Zelefsky
  3. Marisa A Kollmeier
    213 Kollmeier
  4. Behfar Ehdaie
    153 Ehdaie
  5. Samson W Fine
    438 Fine
  6. Victor Reuter
    1198 Reuter
  7. Debra Alyssa Goldman
    155 Goldman
  8. Neelam Tyagi
    141 Tyagi
  9. Sean Matthew McBride
    260 McBride
  10. Margaret F. Hopkins
    10 Hopkins