Stereotactic body radiation therapy for lung metastases from soft tissue sarcoma

Abstract

Purpose: To appraise the role of stereotactic body radiation therapy (SBRT) in patients with lung metastasis from primary soft tissue sarcoma.

Methods: Twenty-eight patients (51 lesions) were analysed. All patients were in good performance status (1-2 eastern cooperative oncology group (ECOG)), unsuitable for surgical resection, with controlled primary tumour and the number of lung metastases was ⩽4. In a risk adaptive scheme, the dose prescription was: 30Gy/1fr, 60Gy/3fr, 60Gy/8fr and 48Gy/4fr. Treatments were performed with Volumetric Modulated Arc Therapy. Clinical outcome was evaluated by thoracic and abdominal computed tomography (CT) scan before SBRT and than every 3months. Toxicity was evaluated with Common Terminology Criteria for Adverse Events (CTCAE) scale version 4.0.

Results: Leiomyosarcoma (36%) and synovial sarcoma (25%) were the most common histologies. Five patients (18%) initially presented with pulmonary metastasis, whereas 23 (82%) developed them at a median time of 51months (range 11-311months) from the initial diagnosis. The median follow-up time from initial diagnosis was 65months (5-139months) and from SBRT was 21months (2-80months). No severe toxicity (grades III-IV) was recorded and no patients required hospitalisation. The actuarial 5-years local control rate (from SBRT treatment) was 96%. Overall survival at 2 and 5years was 96.2% and 60.5%, respectively. At last follow-up 15 patients (54%) were alive. All other died because of distant progression.

Conclusions: SBRT provides excellent local control of pulmonary metastasis from soft tissue sarcoma (STS) and may improve survival in selected patients. SBRT should be considered for all patients with pulmonary metastasis (PM) and evaluated in a multidisciplinary team.

Keywords: Lung; RapidArc; Soft tissue sarcoma; Stereotactic body radiation therapy.