Stereotactic Body Radiotherapy for Pulmonary Metastases from Soft Tissue Sarcomas: Excellent Local Lesion Control and Improved Patient Survival

Abstract

Purpose/Objective(s)Patients with pulmonary metastases (PM) from soft tissue sarcomas (STS) have historically been treated with surgery and/or chemotherapy; however, survival is limited. Since 2001 we have treated extracranial metastases from various primary malignancies with stereotactic body radiation therapy (SBRT) resulting in outstanding local control (LC), unexpectedly favorable overall survival (OS), and minimal toxicity. We postulated that SBRT for patients with PM from STS yields excellent LC and OS.Materials/MethodsThe medical records of 52 of 54 consecutive adult patients with PM from STS seen at our institution from 1990-2006 were evaluated. Most patients received multi-modality treatment with some combination of surgery, chemotherapy, and/or radiation. Chemotherapy was usually anthracycline-based. Surgical procedures varied. SBRT used the Novalis ExacTrac patient positioning platform, vacuum bag immobilization, and relaxed end-expiratory breath holding techniques. The PTV = GTV + 7-10 mm; dose was prescribed to the isocenter, usually 50 Gy in 10 fractions. Lesion growth ≥20% was considered a local failure (LF). Actuarial LC and OS were calculated using the Kaplan-Meier Method. LC was calculated from end of SBRT to LF or last CT scan; OS was calculated from diagnosis of PM to death or last follow-up.ResultsMedian age at diagnosis was 56 (range, 18-88) years. Extremities were the most frequent site (60%) of initial presentation. Leiomyosarcoma (23%), MFH (19%), and synovial sarcoma (15%) were the most common histologies. 48% percent of patients initially presented with PM, with the remainder developing PM at a median of 0.7 (range, 0.3-7.3) years after initial diagnosis. Median follow-up from diagnosis of PM was 0.9 (range, 0.3-7.3) years. 14 patients underwent SBRT, with 74 lesions treated. The median number of lesions treated per patient was 4 (range, 1-16) while the median number of lesions treated per session was 3.5 (range, 1-6). The 3-year actuarial LC was 82%. No patients experienced grade 3 or higher toxicity. Median OS was 2.1 (range, 0.8-11.5) years for patients treated with SBRT and 0.6 (0.1-7.8) years for those who never received SBRT (p value = 0.002).ConclusionsWhile survival for patients with PM from STS is generally limited, many are palliated and a subset experience prolonged survival or possibly cure. SBRT provided excellent LC of PM and may extend OS. Although selection bias clearly exists, it occurs in both directions: some patients referred for SBRT had PM with favorable size, location, and/or number, while others were not candidates for resection due to comorbid conditions and/or the distribution, location, and/or size of PM. We are establishing criteria for the use of SBRT for STS patients with PM. Purpose/Objective(s)Patients with pulmonary metastases (PM) from soft tissue sarcomas (STS) have historically been treated with surgery and/or chemotherapy; however, survival is limited. Since 2001 we have treated extracranial metastases from various primary malignancies with stereotactic body radiation therapy (SBRT) resulting in outstanding local control (LC), unexpectedly favorable overall survival (OS), and minimal toxicity. We postulated that SBRT for patients with PM from STS yields excellent LC and OS. Patients with pulmonary metastases (PM) from soft tissue sarcomas (STS) have historically been treated with surgery and/or chemotherapy; however, survival is limited. Since 2001 we have treated extracranial metastases from various primary malignancies with stereotactic body radiation therapy (SBRT) resulting in outstanding local control (LC), unexpectedly favorable overall survival (OS), and minimal toxicity. We postulated that SBRT for patients with PM from STS yields excellent LC and OS. Materials/MethodsThe medical records of 52 of 54 consecutive adult patients with PM from STS seen at our institution from 1990-2006 were evaluated. Most patients received multi-modality treatment with some combination of surgery, chemotherapy, and/or radiation. Chemotherapy was usually anthracycline-based. Surgical procedures varied. SBRT used the Novalis ExacTrac patient positioning platform, vacuum bag immobilization, and relaxed end-expiratory breath holding techniques. The PTV = GTV + 7-10 mm; dose was prescribed to the isocenter, usually 50 Gy in 10 fractions. Lesion growth ≥20% was considered a local failure (LF). Actuarial LC and OS were calculated using the Kaplan-Meier Method. LC was calculated from end of SBRT to LF or last CT scan; OS was calculated from diagnosis of PM to death or last follow-up. The medical records of 52 of 54 consecutive adult patients with PM from STS seen at our institution from 1990-2006 were evaluated. Most patients received multi-modality treatment with some combination of surgery, chemotherapy, and/or radiation. Chemotherapy was usually anthracycline-based. Surgical procedures varied. SBRT used the Novalis ExacTrac patient positioning platform, vacuum bag immobilization, and relaxed end-expiratory breath holding techniques. The PTV = GTV + 7-10 mm; dose was prescribed to the isocenter, usually 50 Gy in 10 fractions. Lesion growth ≥20% was considered a local failure (LF). Actuarial LC and OS were calculated using the Kaplan-Meier Method. LC was calculated from end of SBRT to LF or last CT scan; OS was calculated from diagnosis of PM to death or last follow-up. ResultsMedian age at diagnosis was 56 (range, 18-88) years. Extremities were the most frequent site (60%) of initial presentation. Leiomyosarcoma (23%), MFH (19%), and synovial sarcoma (15%) were the most common histologies. 48% percent of patients initially presented with PM, with the remainder developing PM at a median of 0.7 (range, 0.3-7.3) years after initial diagnosis. Median follow-up from diagnosis of PM was 0.9 (range, 0.3-7.3) years. 14 patients underwent SBRT, with 74 lesions treated. The median number of lesions treated per patient was 4 (range, 1-16) while the median number of lesions treated per session was 3.5 (range, 1-6). The 3-year actuarial LC was 82%. No patients experienced grade 3 or higher toxicity. Median OS was 2.1 (range, 0.8-11.5) years for patients treated with SBRT and 0.6 (0.1-7.8) years for those who never received SBRT (p value = 0.002). Median age at diagnosis was 56 (range, 18-88) years. Extremities were the most frequent site (60%) of initial presentation. Leiomyosarcoma (23%), MFH (19%), and synovial sarcoma (15%) were the most common histologies. 48% percent of patients initially presented with PM, with the remainder developing PM at a median of 0.7 (range, 0.3-7.3) years after initial diagnosis. Median follow-up from diagnosis of PM was 0.9 (range, 0.3-7.3) years. 14 patients underwent SBRT, with 74 lesions treated. The median number of lesions treated per patient was 4 (range, 1-16) while the median number of lesions treated per session was 3.5 (range, 1-6). The 3-year actuarial LC was 82%. No patients experienced grade 3 or higher toxicity. Median OS was 2.1 (range, 0.8-11.5) years for patients treated with SBRT and 0.6 (0.1-7.8) years for those who never received SBRT (p value = 0.002). ConclusionsWhile survival for patients with PM from STS is generally limited, many are palliated and a subset experience prolonged survival or possibly cure. SBRT provided excellent LC of PM and may extend OS. Although selection bias clearly exists, it occurs in both directions: some patients referred for SBRT had PM with favorable size, location, and/or number, while others were not candidates for resection due to comorbid conditions and/or the distribution, location, and/or size of PM. We are establishing criteria for the use of SBRT for STS patients with PM. While survival for patients with PM from STS is generally limited, many are palliated and a subset experience prolonged survival or possibly cure. SBRT provided excellent LC of PM and may extend OS. Although selection bias clearly exists, it occurs in both directions: some patients referred for SBRT had PM with favorable size, location, and/or number, while others were not candidates for resection due to comorbid conditions and/or the distribution, location, and/or size of PM. We are establishing criteria for the use of SBRT for STS patients with PM.