Responsiveness to volume change of calcinosis cutis utilizing dual-energy computed tomography in a patient with diffuse cutaneous systemic sclerosis treated with alendronate

Abstract

Background: A 33-year-old pleasant Emirati lady presented to Cleveland Clinic Abu Dhabi with an established diagnosis of diffuse cutaneous systemic sclerosis and calcinosis cutis of 7 years duration from the first non-Raynaud's disease manifestation. She was experiencing pain, open wounds and visible palpable stones involving the knees. Despite treatment over the years with different medications including oral steroids, colchicine, sodium thiosulphate infusions and mycophenolate mofetil, her illness progressed. She was started on alendronate 70 mg weekly on March of 2017 as a treatment option for refractory calcinosis cutis.We examined the usefulness of dual-energy computed tomography (DECT) in excluding monosodium urate (MSU) crystal deposition and further quantified the amount of calcific deposits to assess responsiveness to alendronate after being on the medication for 1 year. There was a clinically meaningful improvement in knee pain, wound healing and volume of calcium deposits pre and post treatment with alendronate. DECT scan is a useful tool that can further characterize the morphology, density and distribution of the calcinosis within the soft tissues as well as providing the added benefit of volume quantification to assess responsiveness to treatments.