Radiologic response assessment in patients with desmoid-type fibromatosis treated with percutaneous cryoablation
摘要
Percutaneous cryoablation (PC) has been incorporated among first-line treatment options for desmoid-type fibromatosis (DF). Loco-regional therapies, including PC, induce tissue changes that may precede measurable tumor shrinkage, thereby limiting the reliability of purely dimensional response criteria. To address this limitation, we compared response evaluation criteria in solid tumors (RECIST) 1.1 and magnetic resonance imaging (MRI)-adapted (M-)RECIST in patients with DF treated with PC.
Materials and methodsWe retrospectively identified all consecutive patients with progressing extra-abdominal DF treated with PC. Responses were assessed with RECIST 1.1 and M-RECIST, the latter relying on T2- and diffusion-weighted imaging, as well as unenhanced and contrast-enhanced T1-weighted imaging, to define residual viable tumor. Non-progression (NPR) and overall response rates (ORR) were defined as the percentage of patients without radiological progression and partial/complete responses, respectively.
ResultsThirty-four patients (females/males, 26/8) and 37 procedures were identified. RECIST 1.1 and M-RECIST were applicable in 35 and 34 procedures, respectively. At a median follow-up of 15.7 months (interquartile range [IQR] 19.5), RECIST 1.1. Responses were: 10/35 (28.6%) partial response (PR), 22/35 (62.9%) stable disease (SD), and 3/35 (8.6%) progressive disease (PD), with ORR 28.6% and NPR 91.4%. At a median follow-up of 16.0 months (IQR 20.5), M-RECIST responses were: 15/34 (44.1%) complete response (CR), 12/34 (35.3%) PR, 4/34 (11.8%) SD, and 3/34 (8.8%) PD, with ORR 79.4% and NPR 91.2%. Overall concordance was negligible.
ConclusionM-RECIST yielded higher NPR/ORR than RECIST 1.1. These findings pave the way for studies addressing whether this shift in response categorization associates with improved outcomes prediction.
Relevance statementThis work provides supporting evidence for the implementation of residual viable disease assessment in evaluating DF responses to PC.
Key PointsIn patients with DF, responses to cryoablation can be characterized using purely dimensional and viability-based criteria. RECIST 1.1 and M-RECIST yielded complete agreement for PD. M-RECIST may refine response categorization below the progression threshold.