LBA 19 - Stereotactic Radiotherapy vs. Stereotactic Boost for Prostate Cancer: 2-year Toxicity and Quality of Life from a Randomized Controlled Trial (TROG 1801 NINJA)
Presenter(s)
J. M. Martin1,2, C. I. Tang3,4, S. Dickson5, A. Miller6, D. I. Pryor7,8, V. Do9, T. S. Lim10,11, A. Hayden12, B. T. Nguyen13, E. Wegener1,14, N. Collier15, P. Chan16, S. L. Turner17, C. Lin18, M. Richardson5, P. Greer5,14, E. Brown5, S. Gallagher5, S. Keats9, and M. Sidhom9,19; 1GenesisCare Gateshead, Newcastle, NSW, Australia, 2Calvary Hospital Newcastle, Newcastle, Australia, 3Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia, 45D Clinics, Perth, Australia, 5Radiation Oncology Calvary Mater Newcastle Hospital, Newcastle, Australia, 6Department of Radiation Oncology, Illawarra Cancer Care Centre, Wollongong, Australia, 7Queensland University of Technology, Brisbane, QLD, Australia, 8Princess Alexandra Hospital, Brisbane, QLD, Australia, 9Liverpool and Macarthur Cancer Therapy Centres, Sydney, Australia, 10University of Western Australia, Department of Surgery, Perth, Australia, 11GenesisCare, Fiona Stanley Hospital, Perth, Australia, 12Westmead Cancer Care Centre, Sydney, Australia, 13Canberra Hospital, Canberra 2606, Australia, 14University of Newcastle, Newcastle, Australia, 15Illawarra Cancer Centre, Illawarra, Australia, 16Royal Brisbane and Women's Hospital, Herston, QLD, Australia, 17Sydney Medical School, University of Sydney, Sydney, Australia, 18Dept of Radiation Oncology, Royal Brisbane and Women’s Hospital, Brisbane, QLD, Australia, 19South Western Sydney Clinical School, University of New South Wales, Sydney, Australia
Purpose/Objective(s):
Stereotactic body radiotherapy (SBRT) is non-inferior to longer schedules in the management of localized prostate cancer. Which SBRT schedule achieves the optimal balance between efficacy, side effects and convenience is unknown. We report 2-year adverse events (AEs) and quality of life (QoL) findings from a randomised trial comparing SBRT with SBRT Boost.Materials/Methods:
TROG 1801 NINJA is an open-label, randomised controlled phase 3 trial conducted at 20 centres in Australia and New Zealand. Men aged =18 with an ECOG performance status 0–1 and unfavourable intermediate-risk or low-high risk (Grade Group 4, PSA<20, Stage T1-2) prostate adenocarcinoma were randomly allocated, stratified by centre and risk group, to SBRT (40 Gy in 5 fractions over 2 weeks) or SBRT Boost (20 Gy in two fractions over 1 week, a two week break, then 36Gy in 12 fractions given 4-5/week). Six months of androgen deprivation was delivered, unless a biomarker predicted no additional benefit. Minimally Clinically Important Changes (MCICs) and normalized scores in EPIC-26 QoL as well as CTCAE v5 gastrointestinal and genitourinary AEs up to 24 months are reported. The trial is prospectively registered (ANZCTN 12615000223538).Results:
471 men were randomized between March 2019 and July 2026, 233 to SBRT and 238 to Boost. Median age was 71 years (IQR 66-75yrs). EPIC-26 is normalized to a 100 point scale, with higher scores corresponding to better QoL. 286 men have reached 2 year follow-up, and QoL completion rate was >95% at all timepoints. For GU Obstructive, there were no significant differences at baseline or 6 weeks, but slightly worse at 2 years in the Boost arm (baseline 90v90 p=0.8, 6 weeks 81v79 p=0.2, 2 years 89v83 p=0.003). Similar changes are noted for GU Irritative (baseline 92v91 p=0.4, 6 weeks 89v86 p=0.08, 2 years 88v81 p=0.003). For GI, there were no significant differences at any time point (baseline 96v96 p=1, 6 weeks 91v90 p=0.7, 2 years 94v92 p=0.16). For MCIC, there is a significant divergence at 2 years in GU obstructive (31v45%, p=0.015), but not GU irritative (28v39%, p=0.055) or GI (17v22%, p=0.2). The prevalence of CTCAE GI AE grade=2 was seen in the acute setting in 1% of the SBRT arm and 1% of the boost arm (p=1), and at the 2 year mark in <1% and 1% (p=1). The corresponding figures for GU AE were 12% and 8% acutely (p=0.030) and 7% and 11% at 2 years (p=0.199). No grade=4 events were reported.Conclusion:
Modern prostate SBRT is well tolerated in the first 2 years following treatment. GI AEs or QoL detriments are unusual. After some acute deterioration, GU AEs and QoL return close to baseline in the SBRT group, but some residual changes are seen in the boost group. Subacute AEs has been noted in other prostate SBRT cohorts – longer term follow-up will occur to determine if these changes resolve, as well as any efficacy advantages for the boost regimen.