Magnetic Resonance Imaging–guided Focal Boost to Intraprostatic Lesions Using External Beam Radiotherapy for Localized Prostate Cancer: A Systematic Review and Meta-analysis
Objective: To systematically review clinical outcomes for MRI-guided EBRT focal boost to IPLs.
Evidence acquisition: Three independent reviewers conducted literature searches in three databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The inclusion criteria were original English-language articles from 2000 to 2021 on prospective studies of patients with localized PC (n > 10) receiving an MRI-guided EBRT focal boost to IPLs. The main outcomes and measures were safety, gastrointestinal (GI)/genitourinary (GU) toxicities, quality of life, and biochemical disease outcomes. Weighted random-effects meta-analyses were conducted. Heterogeneity was assessed using the I2 statistic. Publication bias was assessed via funnel plots.
Evidence synthesis: Seventeen studies (1290 patients) were included. There were heterogeneities in patient risk category (low risk, 63; intermediate risk, 532; high risk, 695), MRI utilization, and treatment planning and delivery. All studies reported good safety, with estimated rates of 7.5%/7.0% (95% confidence interval [CI] 4.0–12.1%/2.8–12.8%) and 0.1%/0.2% (95% CI 0–0.4%/0–1.1%) for acute/late cumulative grade ≥2 and grade ≥3 gastrointestinal toxicities, and 29.5%/16.0% (95% CI 17.6–43.0%/8.3–25.7%) and 0.4%/1.3% (95% CI 0.0–1.3%/0.3–3.0%) for acute/late grade ≥2 and grade ≥3 genitourinary toxicities, respectively. Across patients in focal boost studies with follow-up >5 yr, bDFS was 92.4% (95% CI 84.5–97.7%). The overall bDFS was 95.0% (95% CI 91.9–97.4%) regardless of follow-up duration.
Conclusions: MRI-guided EBRT focal boost to IPLs in localized PC was feasible and safe, with low GI/GU toxicities and favorable biochemical disease outcomes. Level 1 evidence supports the superior bDFS of this approach over whole-prostate irradiation for standard fractionation; however, further research is required for hypofractionation and ultra-hypofractionation.
Patient summary: We reviewed 17 studies on the use of magnetic resonance imaging (MRI)-guided radiotherapy with delivery of a higher radiation level to lesions within the prostate that were visible on MRI. This approach was well tolerated and might offer better disease control in prostate cancer over traditional radiotherapy.
Darren M.C. Poon, Jing Yuan, Bin Yang, Linda G.W. Kerkmeijer, Amar U. Kishan, Vedang Murthy, Alison Tree, Almudena Zapatero, Oi Lei Wong
Comprehensive Oncology Centre, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong Special Administrative Region., Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong Special Administrative Region., Medical Physics Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong Special Administrative Region., Department of Radiation Oncology, Radboudumc, Nijmegen, The Netherlands., Department of Radiation Oncology, University of California-Los Angeles, Los Angeles, CA, USA., Department of Radiation Oncology, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Homi Bhabha National Institute, Mumbai, India., Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, London, UK., Radiation Oncology Department, Hospital Universitario de la Princesa, Health Research Institute IIS-IP, Madrid, Spain.
Source: Poon D., Yuan J., Yang B. et al. Magnetic Resonance Imaging–guided Focal Boost to Intraprostatic Lesions Using External Beam Radiotherapy for Localized Prostate Cancer: A Systematic Review and Meta-analysis. European Urology Oncology. 2023. DOI:https://doi.org/10.1016/j.euo.2022.10.001.