Feasibility of using stereotactic body radiation therapy for unresectable soft tissue tumors of the trunk

// Eun Kyung Paik 1 , Mi-Sook Kim 1 , Chul-Koo Cho 1 , Hyung Jun Yoo 1 , Won Il Jang 1 , Young-Seok Seo 2 , Sung-Ho Jin 3 , Dae Geun Jeon 4 and Dong Han Lee 5 1 Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, Korea 2 Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea 3 Department of Surgery, Korea Institute of Radiological and Medical Sciences, Seoul, Korea 4 Department of Orthopedic Surgery, Korea Institute of Radiological and Medical Sciences, Seoul, Korea 5 CyberKnife Center, Korea Institute of Radiological and Medical Sciences, Seoul, Korea Correspondence to: Mi-Sook Kim, email: mskim@kirams.re.kr Keywords: soft tissue tumor; sarcoma; stereotactic body radiation therapy; unresectable; trunk Received: September 07, 2017      Accepted: May 17, 2018      Published: June 12, 2018 ABSTRACT Purpose: To evaluate the feasibility of stereotactic body radiation therapy (SBRT) for unresectable soft tissue tumors of the trunk. Materials and Methods: Between January 2002 and December 2008, 23 patients with 36 lesions of soft tissue tumors, which were located in the trunk and not suitable for resection, underwent SBRT. Among the 36 lesions, 31 were malignant and 5 were benign. The median tumor volume was 24 cm 3 (range, 2.6–213 cm 3 ). SBRT doses ranged from 20 to 48 Gy in 1–5 fractions. Results: With a median follow-up of 73 months, the overall survival (OS) and local control (LC) rates at 5 years were 39% and 52%, respectively. For malignant tumors, the OS and LC rates at 5 years were 28% and 47%, respectively. For benign tumors, the OS and LC rates at 5 years were 80% and 100%, respectively. There was no acute toxicity of grade ≥3. One case of grade 3 late skin toxicity was reported 10 months after SBRT. Conclusion: SBRT may be an effective and safe treatment modality for the local control of unresectable soft tissue tumors of the trunk including tumors of a benign nature.