Adjuvant radiotherapy treatment for soft tissue sarcoma of extremities and trunk. A retrospective mono-institutional analysis

Ruggero Spoto, Andrea Vavassori, Samantha Dicuonzo, Matteo Pepa,  Stefania Volpe, Ombretta Alessandro, Sara Gandini, Benedetta Di Venosa, Eleonora Miglietta, Cristiana Fodor, Gian Orsolini, Pierpaolo Prestianni, Federica Cattani, Stefania Comi, Roberta Lazzari, Giuseppe Renne, Tommaso De Pas, Roberto Orecchia, Elisabetta Pennacchioli, Barbara Jereczek-Fossa

Abstract:

Soft tissue sarcomas (STS) are uncommon, heterogeneous malignant tumors of mesodermal origin. Other than conservative surgery (CS), neoadjuvant or adjuvant radiotherapy (RT) is recommended when the risk of local recurrence is high. The aim of this study is to present our Institutional experience in adjuvant RT for treatment of STS of extremities and trunk (with either brachytherapy (BRT), external beam RT (EBRT), or both) and to provide an insight of toxicity and oncological outcomes for each RT modality. According to the RT treatment approach, patients were divided into three categories: 1) BRT alone; 2) EBRT alone; 3) combined BRT+EBRT. Differences among the three groups were assessed by the Chi-squared test. Patients’ follow-up was performed every 6 months for the first two years after the end of RT and then once a year. Data from 90 patients were analyzed. The overall 3-year distant relapse-free survival (DRFS), progression-free survival (PFS), and overall survival (OS) were 84%, 80%, and 97%, respectively. Acute erythema was the most frequent side effect, although severe grade 3 toxicity was present in 5 patients. Chronic toxicity of any grade was reported in 14 patients. The incidence of chronic toxicity did not show any association with treatment modality. Multivariate analysis suggested a significant correlation between acute toxicity and tumor size, RT modality, and RT dose. In conclusion, good local control and toxicity profile were observed, despite negative patients’ selection at baseline. Further investigation on wider series is warranted in order to define the optimal combination with systemic therapy.