Long-Term Outcomes of TROG 13.01 SAFRON II Randomized Trial of Single- Versus Multifraction Stereotactic Ablative Body Radiotherapy for Pulmonary Oligometastases

Author(s): Shankar Siva, PhD1,2; Pitchaya Sakyanun, MD3; Tao Mai, PhD4; Wenchang Wong, MBBS5; Adeline Lim, MBBS6; Joanna Ludbrook, MBChB7; Catherine Bettington, MBBS8; Angela Rezo, MBBS9; David Pryor, MBBS4; Nicholas Hardcastle, PhD2,10; Tomas Kron, PhD2,10; Braden Higgs, MBBS11; Hien Le, MBBS11; Marketa Skala, MBBS12; Suki Gill, MBBS13; Thomas Eade, MBBS14; Raef Awad, MD12; Giuseppe Sasso, MBChB15; Shalini Vinod, MD16; Rebecca Montgomery, BBiomedSc17; David Ball, MD1,2; and Mathias Bressel, MSc2,18
Source: DOI: 10.1200/JCO.23.00150 Journal of Clinical Oncology 41, no. 19 (July 01, 2023) 3493-3498.
Maem Hussein MD

Dr. Maen Hussein's Thoughts

For our radiation oncology colleagues, any comments? For oligometastases, radiation therapy helps improve survival when added to systemic therapy.


Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.

In a randomized phase II clinical trial, the Trans Tasman Radiation Oncology Group compared single- versus multifraction stereotactic ablative body radiotherapy (SABR) in 90 patients with 133 oligometastases to the lung. The study found no differences in safety, efficacy, systemic immunogenicity, or survival between arms, with single-fraction SABR picked as the winner on the basis of cost-effectiveness. In this article, we report the final updated survival outcome analysis. The protocol mandated no concurrent or post-therapy systemic therapy until progression. Modified disease-free survival (mDFS) was defined as any progression not addressable by local therapy, or death. At a median follow-up of 5.4 years, the 3- and 5-year estimates for overall survival (OS) were 70% (95% CI, 59 to 78) and 51% (95% CI, 39 to 61). There were no significant differences between the multi- and single-fraction arms for OS (hazard ratio [HR], 1.1 [95% CI, 0.6 to 2.0]; P = .81). The 3- and 5-year estimates for disease-free survival were 24% (95% CI, 16 to 33) and 20% (95% CI, 13 to 29), with no differences between arms (HR, 1.0 [95% CI, 0.6 to 1.6]; P = .92). The 3- and 5-year estimates for mDFS were 39% (95% CI, 29 to 49) and 34% (95% CI, 24 to 44), with no differences between arms (HR, 1.0 [95% CI, 0.6 to 1.8]; P = .90). In this patient population, where patients receive SABR in lieu of systemic therapy, one-in-three patients are alive without disease in the long term. There were no differences in outcomes by fractionation schedule.

Author Affiliations

1Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, Australia2Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria, Australia3Department of Radiation Oncology, Phramongkutklao Hospital, Bangkok, Thailand4Princess Alexandra Hospital, Radiation Oncology Centre, Brisbane, Australia5Department of Radiation Oncology, Prince of Wales Hospital, Sydney, Australia6Department of Radiation Oncology, Austin Health, Melbourne, Australia7Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, Australia8Department of Radiation Oncology, Royal Brisbane and Women’s Hospital, Brisbane, Australia9Radiation Oncology Department, Canberra Hospital, Canberra, Australia10Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Australia11Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, Australia12Radiation Oncology, Royal Hobart Hospital, Hobart, Australia13Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Australia14Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales, Australia15Radiation Oncology Department, Auckland City Hospital, Auckland, New Zealand16Liverpool Hospital, Cancer Therapy Centre, Sydney, Australia17TROG Cancer Research, Research Development, Newcastle, Australia18Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Australia

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