Feasibility, safety and outcomes of stereotactic radiotherapy for ultra-central thoracic oligometastatic disease guided by linear endobronchial ultrasound-inserted fiducials

• Published in: Radiotherapy and oncology 2024-12, Vol.201, p.110547, Article 110547
• Main Authors: Sidhu, Calvin, Tang, Colin, Scott, Alison, Yamini Ramamurty, Hema, Yagnik, Lokesh, Morey, Sue, Phillips, Martin, Jacques, Angela, Thomas, Rajesh
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Bronchoscopy; Bronchoscopy - methods; Endobronchial ultrasound; Feasibility Studies; Female; Fiducial; Fiducial Markers; Humans; Lung Neoplasms - pathology; Lung Neoplasms - radiotherapy; Lung Neoplasms - surgery; Male; Middle Aged; Oligometastatic; Radiosurgery - adverse effects; Radiosurgery - methods; Radiotherapy; Retrospective Studies; Thoracic Neoplasms - pathology; Thoracic Neoplasms - radiotherapy; Treatment Outcome
• ISSN: 0167-8140; 1879-0887; 1879-0887
• DOI: 10.1016/j.radonc.2024.110547

•Linear EBUS use to insert fiducials in the central thorax for stereotactic radiotherapy is feasible, safe, and applicable to the ambulatory setting.•Ultra-central stereotactic radiotherapy for thoracic oligometastases using fiducials appears feasible safe, with short-term mild complications.•Fiducial-guided stereotactic radiotherapy to ultra-central thoracic oligometastates led to good short-term and moderate long-term survival. Local treatment of oligometastases has been found to improve survival and prognosis. Stereotactic body radiotherapy (SBRT) has emerged as a treatment option for oligometastases but its use in ultra-central (UC) areas can cause significant toxicity and mortality. Fiducial markers (FM) can be used to improve SBRT accuracy, and can be inserted in the central thorax using linear endobronchial ultrasound (EBUS) bronchoscopy. Outcomes of FM-guided SBRT for UC thoracic oligometastases is unknown. A single-centre retrospective study investigating the feasibility, safety and outcomes of both linear EBUS-inserted FMs and subsequent FM-guided SBRT for UC-oligometastatic disease. Motion analyses of FMs were also performed. Thirty outpatients underwent 32 EBUS-FM insertion procedures with 100 % success, and no major procedural mortality or morbidity. Minor complications were 4.8 % incidence of delayed FM-displacement. UC FM-guided SBRT was completed in 20 patients with 99.9 % fractions delivered. Median SBRT dose delivered was 40 Gy over a median of 8 fractions. Majority of adverse events were Grade 1 and there was no SBRT-related mortality. Local control with SBRT was 95 %, with overall survival at 1-year and 3-years of 90 % and 56.3 % respectively. Median overall survival after SBRT was 43.6 months. FM movements in UC areas were recorded being greatest in the superior-inferior axis. Combined linear EBUS sampling and FM-insertion in UC thoracic oligometastatic disease is feasible and safe. UC-SBRT to oligometastases using FM guidance was found to have minimal complications and associated with moderate survival up to 3 years post-treatment.