A moderate dose of preoperative radiotherapy may improve resectability in myxoid liposarcoma.

Abstract

BACKGROUND:

Histotype specific neoadjuvant therapy response data is scarce in soft tissue sarcomas. This study aimed to assess the impact of a moderate radiotherapy (RT) dose on resectability and to correlate MRI parameters to pathological treatment response in Myxoid Liposarcoma (MLS).

METHODS:

This prospective, multicenter, single-arm, phase 2 trial assessed the radiological effects of 36 Gy of preoperative radiotherapy in primary non-metastatic MLS (n=34). Distance of the tumor to the neurovascular bundle, tumor dimensions, fat fraction, enhancing fraction were determined on MRI scans at baseline, after 8 and 16 fractions, and preoperatively. Pathological response was established by central pathology review.

RESULTS:

Preoperative radiotherapy resulted in a median increase of 2 mm (IQR 0 to 6) of the distance of the tumor to the neurovascular bundle. As compared to baseline, the median change of the tumor volume, craniocaudal diameter and axial diameter at preoperative MRI were -60% (IQR -74 to -41), -19% (IQR -23 to -7) and -20% (IQR -29 to -12), respectively. The median fat fraction of 0.1 (IQR 0.0-0.1) and enhancing fraction of 0.8 (IQR 0.6 to 0.9) at baseline, changed to 0.2 (IQR 0.1 to 0.5) and to 0.5(IQR 0.4 to 0.9) preoperatively, respectively. Radiological signs of response in terms of volume, enhancing fraction and fat fraction were correlated with specific pathological signs of response like hyalinization, necrosis and fatty maturation.

CONCLUSIONS:

A moderate dose of preoperative radiotherapy may improve resectability in MLS and could facilitate achievement of clear margins and function preservation. MRI features which were predictive for expressions of pathological response, can play a role in further personalization of neoadjuvant treatment strategies in order to improve outcome in MLS.

• Authors: Jules Lansu, Pètra M Braam, Erik van Werkhoven, Astrid N Scholten, Yvonne Schrage, Winan J van Houdt, Kirsten van Langevelde, Rick L Haas
• Journal: European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology (Eur J Surg Oncol) Vol. 47 Issue 10 Pg. 2633-2639 (10 2021) ISSN: 1532-2157 [Electronic] England
• PMID: 34233858 (Publication Type: Clinical Trial, Phase II, Journal Article, Multicenter Study)
• Copyright: Copyright © 2021 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Topics

• Adipose Tissue (diagnostic imaging)
• Adiposity
• Adult
• Blood Vessels (diagnostic imaging)
• Dose Fractionation, Radiation
• Female
• Humans
• Liposarcoma, Myxoid (diagnostic imaging, pathology, radiotherapy, surgery)
• Magnetic Resonance Imaging
• Male
• Margins of Excision
• Middle Aged
• Neoadjuvant Therapy
• Neoplasm, Residual
• Peripheral Nerves (diagnostic imaging)
• Preoperative Period
• Prospective Studies
• Radiotherapy, Adjuvant
• Soft Tissue Neoplasms (diagnostic imaging, pathology, radiotherapy, surgery)
• Tumor Burden