Final Results From a Phase I Dose Escalation Study (DESTROY-1) in Stereotactic Boost After Prior Radiotherapy

Why clinicians should know about it

• Picked for Radiology, Radiation Oncology, Nuclear Medicine, Medical Physics and Imaging (paper of the day, 8 October 2026): Phase I SBRT boost after prior radiotherapy, dose escalation

Abstract

PURPOSE: The aim of the study is to report the final results of the DESTROY-1 dose-escalation study evaluating an stereotactic body radiation therapy (SBRT) boost for persistent disease within 4 months after in-field radiotherapy. MATERIAL/METHODS: Within the DESTROY-1 trial, arms (f) and (g) were designed to evaluate an SBRT boost for persistent disease after prior in-field radiotherapy. Arm (f) included patients previously irradiated with doses ≤50 Gy or with persistent disease in regions previously exposed to small bowel irradiation, whereas arm (g) enrolled patients with persistence in sites receiving prior doses >50 Gy. Dose escalation proceeded through three levels up to a total dose of 35 Gy in arm (f) and 30 Gy in arm (g), respectively. Each cohort was assessed for dose-limiting adverse events, defined as any radiation-related adverse events ≥ grade 3 occurring within 6 months after SBRT. RESULTS: Sixty-nine lesions in 57 patients were treated between 2005 and 2018. Acute adverse events were mostly grade 1-2, with one grade 3 gastrointestinal event in arm (g). Late adverse events were limited, with a single grade 3 lower gastrointestinal event in arm (f). Clinical response was available for 65 lesions, with a disease control rate of 98.4%. One-year local control was 86.5%, while 1-year distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were 70.8%, 63.8%, and 91.9%, respectively. CONCLUSION: Dose escalation up to 35 Gy and 30 Gy in the two study arms was feasible and associated with acceptable adverse events and favorable local control outcomes.

Abstract as published, via PubMed.