The XXXXX trial is a multi-institutional phase I/II study utilizing a combined PSMA PET/MRI approach to treat dominant intraprostatic lesions (DILs) and affected lymph nodes in unfavorable intermediate and high-risk prostate cancer using a five fraction SABR and simultaneous in-field boost (SIB) technique.
Here we report on the primary endpoint of toxicity within 6 months of treatment.
SIB volumes were defined utilizing a PET/MRI acquired using 18F-PSMA 1007. Five fraction SABR was planned to deliver doses (maximum SIB) to prostate 35 Gy (50 Gy), SV 25 Gy (50 Gy) and lymph nodes 25 Gy (35 Gy) while respecting OAR's. Toxicity and QOL were assessed according to CTCAE 5.0 and EPIC-26 during radiation, at 6 weeks post-treatment and at 6 months post treatment.
In total 50 patients were treated, 23 patients had unfavorable intermediate risk disease, 23 were high risk, and 4 were very high-risk prostate cancer. Median prostate SIB of 41.6 Gy (IQR: 39.3-44.8 Gy) was delivered to a median of 1 intra-prostatic lesion. Eighteen patients received nodal treatment. There was a single acute grade 3 GI toxicity of diarrhea and a single late grade 4 GI toxicity of bleeding. With a median follow-up of 12 months, the EPIC-26 scale showed an increase in urinary irritation (p < 0.001) and no differences for urinary incontinence (p=0.12) and GI QOL (p=0.65) and a decrease in hormonal/sexual QOL (p < 0.001 and p < 0.001). Mean ± SD PSA, maximum SUV on PET and maximum MRI PiRADS scores at baseline to 6 months were 15.4 ± 10.3 to 0.18 ± 0.40 ng/mL, 25.5 ± 19.5 to 4.5 ± 7.7, and 4.7 ± 0.6 to 2.9 ± 1.5 respectively.
XXXXX demonstrated acceptable toxicity using 5 fraction SABR with PET/MRI directed SIB to prostate and lymph nodes.
International journal of radiation oncology, biology, physics. 2025 May 09 [Epub ahead of print]
Sherif Ramadan, Andrew Loblaw, Aneesh Dhar, Hatim Fakir, Lucas C Mendez, Andrew Warner, Matt Wronski, John Conyngham, Zahra Kassam, Vibhuti Kalia, Vivian S Tan, Priscila Crivellaro, Aaron D Ward, Jonathan Thiessen, Ting-Yim Lee, David Laidley, Glenn S Bauman
Department of Oncology, Division of Radiation Oncology, London Health Sciences Centre and Western University, London, ON, Canada., Department of Radiation Oncology, Odette Cancer Center, Sunnybrook Health Sciences Centre and Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada., Department of Oncology and Department of Medical Biophysics, London Health Sciences Centre and Western University, London, ON, Canada., Department of Medical Biophysics, Sunnybrook Health Sciences Centre, Toronto, ON, Canada., Patient Partner, London, ON, Canada., Department of Medical Imaging, St. Joseph's Health Care and Western University, London, ON, Canada., Department of Medical Biophysics, Western University and Lawson Health Research Institute, London, ON, Canada., Division of Nuclear Medicine, St. Joseph's Health Centre and Western University, London, ON, Canada., Department of Oncology, Division of Radiation Oncology, London Health Sciences Centre and Western University, London, ON, Canada. Electronic address: .
PubMed http://www.ncbi.nlm.nih.gov/pubmed/40349854