Radiotherapy, volume reduction, and short-term surgical outcomes in the treatment of large myxoid liposarcomas

Abstract

Myxoid liposarcoma (MLS) is the most common subtype of liposarcoma and represents approximately 5% of all adult soft tissue sarcomas (STS) [1,2]. Characteristics of MLS include a t(12:16) translocation and perhaps a more favorable prognosis compared to other liposarcomas despite an unusual predilection for extrapulmonary metastasis [3,4]. Intermediate-and high-grade STS, including MLS, are typically treated with combination surgery and radiotherapy (RT), which have been shown to improve local control when compared to surgery alone. While RT for STS can be performed pre-and Purpose: While tumor volume reduction following radiation has been documented in myxoid liposarcomas, it is unclear whether large tumors experience similar volume reduction to smaller tumors. Materials and Methods: MRI studies performed before and after completion of pre-operative radiation therapy (RT) were examined. Tumor sizes were noted and categorized as large versus small based on size >10 cm. Tumor volumes were calculated, and operative duration and major wound complications were recorded. Results:The median largest tumor dimension was 12.4 cm before RT and 8.7 cm after RT. The median tumor volume was 298.9 cm 3 before RT and 106.9 cm 3 after RT. There was no significant difference in the mean percent tumor volume reduction between large tumors and small tumors (p = 0.11, 56.3% vs. 64.5%). Operative duration most strongly correlated to post-RT MRI volume (R 2 =0.674, p<0.001). Despite volume reduction, tumors that were large on presentation were more likely to experience major wound complications post-operatively. Conclusion: Radiation appears to be as effective at reducing myxoid liposarcoma tumor volume in large and small tumors. However, large tumors on presentation appear more likely to experience wound complications despite tumor volume reduction. Future studies should investigate disease-related outcomes as a factor of volume reduction in myxoid liposarcoma.

Prognostic factors and nomogram construction for primary retroperitoneal myxoid/round cell liposarcoma: an analysis of population-based data

“…Magnetic resonance imaging (MRI) examination of tumor size before and after radiotherapy revealed a median maximum tumor size of 12.4 cm and a median tumor volume of 298.9 cm 3 . After radiotherapy, the median maximum tumor size on MRI was 8.7 cm, and the median tumor volume was 106.9 cm 3 [46]. However, the role of radiotherapy in liposarcoma should be explored in a prospective trial.…”

Myxoid liposarcoma: a well-defined clinical target variant in radiotherapy for soft tissue sarcoma

“…In fact, the higher incidence of postoperative wound complications that were found to be significantly higher in preoperative RT over postoperative RT is the main reason for avoiding the addition of preoperative RT in real-world clinical practice [4]. Although a significant decrease in wound complications was not observed in the study by Lee et al [14], the reduction in resected tissue could reduce the risk of wound complications. This point may be more important, especially in radiosensitive MLS, in that the local control rate is sufficiently satisfactory even after limited resection following preoperative RT [15].…”

“…Recently, Lee et al [ 14 ] reported an interesting article in the Radiation Oncology Journal on volume reduction and short-term surgical outcomes in large-sized MLS after 50 Gy over 25 fractions of preoperative RT, in which 24 patients were analyzed by dividing them into two groups based on the pretreatment tumor size of 10 cm. There was no significant difference between the two groups in terms of volume reduction, with a mean percentage of 56.3% (range, 22.4% to 90.9%) in the large compared with 64.5% (range, -18.4% to 91.7%) in the small tumor group.…”

“…The study by Lee et al [ 14 ] had several important limitations, including a small sample size and retrospective design as the authors admitted. However, it provides valuable clinical information to compare the RT response and postoperative wound complications of large MLS with small MLS, which remains a concern for experts in this field through consistent treatment of relatively rare tumors.…”