Repeat stereotactic body radiotherapy for oligometastatic disease

• Published in: Radiotherapy and oncology Vol. 184; p. 109671
• Main Authors: Willmann, Jonas, Adilovic, Selma, Vlaskou Badra, Eugenia, Christ, Sebastian M., Ahmadsei, Maiwand, Tanadini-Lang, Stephanie, Mayinger, Michael, Guckenberger, Matthias, Andratschke, Nicolaus
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.07.2023
• Subjects: Humans; Lung Neoplasms - secondary; Metastasis-directed therapy; Oligometastatic disease; Progression-Free Survival; Radiosurgery - adverse effects; Repeat stereotactic body radiotherapy; Retrospective Studies; Treatment Outcome; Metastasis-directed therapy; Oligometastatic disease; Repeat stereotactic body radiotherapy
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2023.109671

•Comparison of repeat and single course SBRT for oligometastatic disease.•Patients treated with repeat SBRT had longer OS, yet shorter PFS.•Among patients surviving at least 1 year after initial SBRT, OS was comparable.•Distant failure (with a single metastasis) was more common in repeat SBRT patients.•Previous systemic therapy and distant metastasis velocity predicted repeat SBRT. Patients with oligometastatic disease (OMD) treated with metastasis-directed definitive local therapy such as stereotactic body radiotherapy (SBRT) are at risk of developing new metastases. Here, we compare characteristics and outcomes of patients treated with a single course and repeat SBRT. OMD patients treated with SBRT to 1–5 metastases were included in this retrospective study, and classified as single course or repeat SBRT. Progression-free survival (PFS), widespread failure-free survival (WFFS), overall survival (OS), systemic therapy-free survival (STFS) and cumulative incidence of different first failures were analyzed. Patient and treatment characteristics predicting the use of repeat SBRT were investigated using univariable and multivariable logistic regression. Among the 385 patients included, 129 and 256 received repeat or single course SBRT, respectively. The most common primary tumor and OMD state in both groups were lung cancer and metachronous oligorecurrence. Patients treated with repeat SBRT had shorter PFS (p < 0.0001), while WFFS (p = 0.47) and STFS (p = 0.22) were comparable. Distant failure, particularly with a single metastasis, was more frequently observed in repeat SBRT patients. Repeat SBRT patients had longer median OS (p = 0.01). On multivariable logistic regression, low distant metastases velocity and more previous lines of systemic therapy significantly predicted the use of repeat SBRT. Despite shorter PFS and comparable WFFS and STFS, repeat SBRT patients had longer OS. The role of repeat SBRT for OMD patients warrants further prospective investigation, focussing on predictive factors to select patients that might derive a benefit.