Hypofractionated Radiotherapy in Locally Advanced Myxoid Liposarcomas of Extremities or Trunk Wall: Results of a Single-Arm Prospective Clinical Trial.

Hanna Koseła-Paterczyk,Anna Szumera-Ciećkiewicz,Piotr Rutkowski,Andrzej Cieszanowski,Michał Wągrodzki,Aneta Borkowska,Marcin Zdzienicki,Patrycja Castaneda-Wysocka,Tadeusz Morysiński,Tomasz Goryń,Paweł Teterycz,Mateusz Spałek

doi:10.3390/jcm9082471

Abstract

Introduction: Myxoid liposarcoma (MLPS) has been reported to be more radiosensitive compared with other soft tissue sarcomas. The main objective of the study was to assess the efficacy of hypofractionated radiotherapy (RT) in the preoperative setting in patients with locally advanced primary MLPS. Methods: Single-arm prospective exploratory clinical trial enrolled MLPS patients for preoperative 5 × 5 Gy RT with delayed surgery. The endpoints of the study were the rate of early wound healing complications and 5-year local control rate. Results: 29 patients (pts) were included, all had tumors located on the lower limb. The median maximum size of the tumor was 13 cm (IQR 10–15 cm). Early RT tolerance was good. Postoperative wound complications occurred in 11 pts (37.9%), late complications concerned 13.8% of patients. A total of 27 patients were included for the efficacy analyses. The pathological features of response to RT were detected in all analyzed surgical specimens. In 25 patients R0 margins were achieved, two patients had an R1 resection. None of the patients had local recurrence. Conclusion: Preoperative hypofractionated RT with a prolonged gap between RT and surgery is a feasible method of the management of MLPS, providing a good local control and low rates of treatment toxicity.

Highlights

Myxoid liposarcoma (MLPS) has been reported to be more radiosensitive compared with other soft tissue sarcomas
The only factors having a significant impact on the disease-free survival (DFS) were the grade (p = 0.00074, by log-rank test) (Figure 1) of the tumor and the percentage of round cell component (RCC) (p = 0.009; HR = 1.270 per 1% change; 95%CI 1.063–1.518)
Our study showed that hypofractionated RT is efficient, safe, and feasible in patients with MLPS who are qualified for the preoperative treatment

Summary

Introduction

Myxoid liposarcoma (MLPS) has been reported to be more radiosensitive compared with other soft tissue sarcomas. The main objective of the study was to assess the efficacy of hypofractionated radiotherapy (RT) in the preoperative setting in patients with locally advanced primary MLPS. Results: 29 patients (pts) were included, all had tumors located on the lower limb. Conclusion: Preoperative hypofractionated RT with a prolonged gap between RT and surgery is a feasible method of the management of MLPS, providing a good local control and low rates of treatment toxicity. MLPS is localized in the deep soft tissue of the extremities, usually the proximal thigh [1,2]. Pathological findings show a lesion composed of uniform, round, or oval primitive nonlipogenic mesenchymal cells with lipoblasts gathered peripherally or near the blood vessels, surrounded by myxoid stroma [3]. Diagnosis of MLPS can be confirmed by the finding of a specific chromosomal translocation t(12;16)(q13;p11), detected in more than 95% of cases, which results in fusion of DDIT3 (CHOP) gene and FUS (TLS) gene [4,5]

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Conclusion