Selective sparing of bladder and rectum sub-regions in radiotherapy of prostate cancer combining knowledge-based automatic planning and multicriteria optimization Articles uri icon

authors

publication date

  • October 2023

start page

  • 1

end page

  • 10

volume

  • 28,100488

International Standard Serial Number (ISSN)

  • 2405-6316

abstract

  • Background and Purpose: The association between dose to selected bladder and rectum symptom-related sub-
    regions (SRS) and late toxicity after prostate cancer radiotherapy has been evidenced by voxel-wise analyses. The
    aim of the current study was to explore the feasibility of combining knowledge-based (KB) and multi-criteria
    optimization (MCO) to spare SRSs without compromising planning target volume (PTV) dose delivery,
    including pelvic-node irradiation.
    Materials and Methods: Forty-five previously treated patients (74.2 Gy/28fr) were selected and SRSs (in the
    bladder, associated with late dysuria/hematuria/retention; in the rectum, associated with bleeding) were
    generated using deformable registration. A KB model was used to obtain clinically suitable plans (KB-plan). KB-
    plans were further optimized using MCO, aiming to reduce dose to the SRSs while safeguarding target dose
    coverage, homogeneity and avoiding worsening dose volume histograms of the whole bladder, rectum and other
    organs at risk. The resulting MCO-generated plans were examined to identify the best-compromise plan (KB +
    MCO-plan).
    Results: The mean SRS dose decreased in almost all patients for each SRS. D1% also decreased in the large
    majority, less frequently for dysuria/bleeding SRS. Mean differences were statistically significant (p < 0.05) and
    ranged between 1.3 and 2.2 Gy with maximum reduction of mean dose up to 3–5 Gy for the four SRSs. The better
    sparing of SRSs was obtained without compromising PTVs coverage.
    Conclusions: Selectively sparing SRSs without compromising PTV coverage is feasible and has the potential to
    reduce toxicities in prostate cancer radiotherapy. Further investigation to better quantify the expected risk
    reduction of late toxicities is warranted.

subjects

  • Biology and Biomedicine

keywords

  • prostate cancer; radiotherapy; automated planning; dose-outcome correlation; multi-criteria optimization