Stereotactic radiotherapy for soft tissue and bone sarcomas: real-world evidence

Mateusz Jacek Spałek; Paweł Teterycz; Aneta Borkowska; Jan Poleszczuk; Piotr Rutkowski

doi:10.1177/17588359211070646

Stereotactic radiotherapy for soft tissue and bone sarcomas: real-world evidence

Ther Adv Med Oncol. 2022 Feb 14:14:17588359211070646. doi: 10.1177/17588359211070646. eCollection 2022.

Authors

Mateusz Jacek Spałek¹, Paweł Teterycz², Aneta Borkowska², Jan Poleszczuk³, Piotr Rutkowski²

Affiliations

¹ Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie National Research Institute of Oncology, 02-781 Warsaw, Poland.
² Department of Soft Tissue/Bone Sarcoma and Melanoma, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.
³ Department of Computational Oncology, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland.

Abstract

Introduction: Selected patients with locally advanced or metastatic soft tissue and bone sarcomas (STBS) may benefit from intensive local treatment, such as stereotactic radiotherapy (SRT). This study aimed to summarize the utilization and outcomes of SRT in STBS and to identify predictive factors for progression and survival.

Materials and methods: Consecutive patients with advanced STBS who underwent STBS in a sarcoma tertiary center were identified. We collected tumor- and treatment-related factors. Endpoints comprised time to local progression (TTLP), local progression-free survival (LPFS), time to progression, progression-free survival, and overall survival (OS). The Cox proportional-hazards model was used to identify prognostic factors.

Results: We identified 141 patients who underwent 233 SRTs. Median follow-up was 21 months. Local and distant progression occurred after 19 and 163 SRTs, respectively. SRT for lung metastases was predictive for better TTLP and LPFS (hazard ratio, HR = 0.12, p = 0.007 and HR = 0.42, p = 0.002, respectively). Bone sarcoma (HR for TTLP = 3.18, p = 0.043; HR for LPFS = 1.99, p = 0.028) and lower administered dose (HR for TTLP = 0.98, p = 0.007; HR for LPFS = 0.99, p = 0.012) were predictive for worse TTLP and LPFS. SRT for oligometastases (HR = 0.46, p = 0.021) and lung metastases (HR = 0.55, p = 0.046) was predictive for better OS, whereas diagnosis of bone sarcoma (HR = 2.05, p = 0.029) was predictive for worse OS.

Conclusion: SRT provides excellent local control in STBS patients without significant toxicity. Patients with oligometastatic disease, lung metastases, and soft tissue sarcomas benefit the most from SRT. The dose escalation moderately enhances local control; however, it does not translate into better survival.

Keywords: image-guided radiation therapy; individualized medicine; metastases; rare diseases; sarcoma; stereotactic body radiotherapy; targeted radiotherapy.