(P 257) SELECTIVE INTRA-ARTERIAL DOXORUBICIN-ELUTING EMBOLIZATION FOR DESMOID FIBROMATOSIS: A COMBINED PROSPECTIVE AND RETROSPECTIVE STUDY

Objective: Desmoid fibromatoses are local aggressive mesenchymal tumors with limited treatment options. Due to its toxicity, doxorubicin is generally reserved for rapidly growing and/or life-threatening desmoids. Doxorubicin can be ionically bound to sulfonate -coated hydrogel microbeads, allowing for selective endovascular drug delivery via microbead-loaded doxorubicin eluting embolization. We aimed to evaluate the safety and efficacy of selective intra-arterial doxorubicin-eluting embolization for intra and extra abdominal desmoid fibromatoses.

Methods: This was a combined prospective and retrospective study involving 24 patients treated at six tertiary medical centers. All patients underwent at least one session of selective intra-arterial doxorubicin-eluting embolization therapy. MRI was utilized for imaging follow up. The primary outcome was radiological response as reflected by tumor volume, T2 intensity and RECIST 1.1 criteria. Safety was assessed using the CTCAE grading system.

Results: At a median follow-up interval of 8 months (IQR 3-13), there was a median volume decrease of 59% (IQR 40 -71). T2 MRI signal intensity dropped a median 36% (IQR 19 – 54.8). Using RECIST 1.1 criteria, 9 (39%) patients achieved a partial response, 12 (52%) had stable disease and 2 (9%) had progressive disease. One patient (4%) experienced a grade 3-4 adverse event.

Conclusion: For select patients with desmoid fibromatosis, doxorubicin-eluting therapy is an effective and safe therapeutic option.