Prognosis of extremity soft tissue sarcomas (ESTS) and retroperitoneal sarcomas (RPS) is currently estimated on clinical-pathological features, as those incorporated in the Sarculator nomogram. This study investigated the added value of end-point specific radiomic signatures (RS) in patients with primary ESTS and RPS.
We retrospectively analysed data from patients with a ESTS (N = 100) or a RPS (N = 116) who underwent surgery (Jan2011-Dec2015) at one sarcoma reference institute and had magnetic resonance imaging (MRI) or computed tomography (CT) scan, respectively. Radiomic features were extracted from DICOM files of MRI and CT scan for ESTS and RPS, respectively. The study end-points were incidence of distant metastases (DM) and overall survival (OS) for ESTS and disease-free survival (DFS) and OS for RPS. A RS was established for each end-point. Models discriminative ability was measured using the Harrell c-index (C).
ESTS histology was undifferentiated pleomorphic sarcoma, myxofibrosarcoma, myxoid liposarcoma, dedifferentiated/pleomorphic liposarcoma, and others in 28, 21, 18, 9, and 24 patients, respectively. At a median follow-up of 61 months, the 5-yr DM-free rate and OS were 73.6% (95%CI 64.2-82.2%) and 73.4% (95%CI 64.5-83.6), respectively. A prognostic model based on the Sarculator and a DM-RS achieved higher C (0.86, 95%CI 0.77-0.93) than the Sarculator alone (0.83, 95%CI 0.71-0.94). For OS, the RS was not able to increase the Sarculator discriminative ability (Sarculator and OS-RS: C = 0.73, 95%CI 0.62-0.82; Sarculator alone: C = 0.72, 95%CI 0.62-0.81). RPS histology was well differentiated liposarcoma, dedifferentiated liposarcoma, leiomyosarcoma, and other in 22 (19%), 60 (52%), 22 (19%), and 12 (10%) patients, respectively. At a median follow-up of 58 months, 5-yr DFS and OS were 46.7% (95%CI, 37.8-57.6%) and 68% (95% CI 59.9-79.0%), respectively. RS extracted from CT scan without contrast enhancement slightly improve the discriminative ability of the Sarculator for DFS (Sarculator and DFS-RS: C = 0.65, 95%CI 0.57-0-72; Sarculator alone: C = 0.63, 95%CI 0.55-0.70) but not for OS (0.70, 95%CI 0.60-0.80 and 0.69, 95%CI 0.59-0.79, respectively).
RS did not improve the discriminative ability of the Sarculator for OS. The added value for RS in relapse prediction (DM incidence for ESTS and DFS for RPS) deserves further investigations.
This article is authored also by Synbrain data scientists and collaborators. READ THE FULL ARTICLE