The latest research published in the New England Journal of Medicine proves that 5 SBRT Radiation Therapy Sessions With CyberKnife Are As Effective and Safe as Other Types of Radiation Requiring 32 or 42 Treatment Sessions for Low-to-Intermediate-Risk Localized Prostate Cancer
Five-fraction SBRT was non-inferior to control radiotherapy with respect to biochemical or clinical failure and may be an efficacious treatment option for patients with low-to-intermediate-risk localized prostate cancer.
Here’s the research proving it.
BACKGROUND: Whether stereotactic body radiotherapy (SBRT) is non-inferior to conventionally or moderately hypo-fractionated regimens with respect to biochemical or clinical failure in patients with localized prostate cancer is unclear.
METHODS: We conducted a phase 3, international, open-label, randomized, controlled trial. Men with stage T1 or T2 prostate cancer, a Gleason score of 3+4 or less, and a prostate-specific antigen (PSA) level of no more than 20 ng per milliliter were randomly assigned (in a 1:1 ratio) to receive SBRT (36.25 Gy in 5 fractions over a period of 1 or 2 weeks) or control radiotherapy (78 Gy in 39 fractions over a period of 7.5 weeks or 62 Gy in 20 fractions over a period of 4 weeks). Androgen-deprivation therapy was not permitted. The primary end point was freedom from biochemical or clinical failure, with a critical hazard ratio for noninferiority of 1.45. The analysis was performed in the intention-to-treat population.
RESULTS: A total of 874 patients underwent randomization at 38 centers (433 patients in the SBRT group and 441 in the control radiotherapy group) between August 2012 and January 2018.
The median age of the patients was 69.8 years, and the median PSA level was 8.0 ng per milliliter; the National Comprehensive Cancer Network risk category was low for 8.4% of the patients and intermediate for 91.6%.
At a median follow-up of 74.0 months, the 5-year incidence of freedom from biochemical or clinical failure was 95.8% (95% confidence interval [CI], 93.3 to 97.4) in the SBRT group and 94.6% (95% CI, 91.9 to 96.4) in the control radiotherapy group (unadjusted hazard ratio for biochemical or clinical failure, 0.73; 90% CI, 0.48 to 1.12; P=0.004 for non-inferiority), which indicated the non-inferiority of SBRT.
At 5 years, the cumulative incidence of late Radiation Therapy Oncology Group (RTOG) grade 2 or higher genitourinary toxic effects was 26.9% (95% CI, 22.8 to 31.5) with SBRT and 18.3% (95% CI, 14.8 to 22.5) with control radiotherapy (P<0.001), and the cumulative incidence of late RTOG grade 2 or higher gastrointestinal toxic effects was 10.7% (95% CI, 8.1 to 14.2) and 10.2% (95% CI, 7.7 to 13.5), respectively (P=0.94).
CONCLUSIONS: Five-fraction SBRT was non-inferior to control radiotherapy with respect to biochemical or clinical failure and may be an efficacious treatment option for patients with low-to-intermediate-risk localized prostate cancer as defined in this trial.
(Funded by Accuray and others; PACE-B ClinicalTrials.gov number, NCT01584258.
NOTES: The views expressed in this article are those of the authors and not necessarily those of the NHS, the National Institute for Health and Care Research (NIHR), or the Department of Health.
A data sharing statement provided by the authors is available with the full text of this article at NEJM.org.
Supported by funding from Accuray to the Royal Marsden NHS Foundation Trust for trial management, international study coordination, and data analysis.
In the United Kingdom, excess treatment costs were met by the NHS. The NIHR provided support to facilitate trial recruitment at U.K. sites.
Radiotherapy quality assurance was provided by the NIHR-funded National Radiotherapy Trials Quality Assurance Group. The Canadian Cancer Clinical Trials Network and Cure Prostate Cancer Canada provided funding in the form of infrastructure support and per-case funding to eligible clinical trials programs for Canadian sites. The Institute of Cancer Research Clinical Trials and Statistics Unit receives programmatic grant funding from Cancer Research UK (grant number C1491/A15955), which supported in part this endorsed trial (CRUKE/12/025).
Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.
We thank our patients, the investigators, and the research support staff at all participating centers, and past and present members of the independent data monitoring committee, trial steering committee, and trial management group (listed in Section S1 in the Supplementary Appendix).
Authors: Nicholas vanAs, M.D., Clare Griffin, M.Sc., Alison Tree, M.D., Jaymini Patel, Ph.D.,
Peter Ostler, F.R.C.R.,
Hans vandeVoet, M.D., Andrew Loblaw, M.D., and Emma Hall, Ph.D.
Published October 16, 2024
N Engl J Med 2024;391:1413-1425
DOI: 10.1056/NEJMoa2403365
https://www.nejm.org/doi/full/10.1056/NEJMoa2403365