Intermittent Administration Regimen of Sirolimus for Refractory Cervicofacial Lymphatic Malformation.

Abstract

The cervicofacial lymphatic malformations (LMs) often have poor outcomes due to their microcystic component and diffuse infiltration. Mostly, traditional treatments are inadequate for these refractory cases. Recent researches have shown that sirolimus is effective in the treatment of complicated LMs, however, there is still no standard strategy. To evaluate the efficacy and safety of intermittent oral sirolimus in treating refractory cervicofacial LMs as a second-line treatment. Fifteen pediatric patients of refractory cervicofacial LMs were retrospectively analyzed in this study. All the cases had received traditional therapy before, but could not completely control the symptoms and eliminate lesions. As a remedy, sirolimus was then proceeded with an intermittent administration regimen, that is 3 continuous months as a course and started the next course after 1 month interval. The clinical characteristics, imaging data of patients, the changes in the signs and symptoms observed, and associated adverse effects were collected and analyzed. The patients initiated sirolimus therapy at the average age of 2.3 years (range 28 days-8 years 9 months). At the end point of the study, 2 patients remained on sirolimus in continuous courses of treatment. Of 13 patients who withdrawn therapy, 4 had restarted due to recurrence of symptoms and re-expansion of LMs. All patients demonstrated reduction in residual LMs and complete disappearance of symptoms during treatment, and 2 patients with complete resolution on imaging. Toxicity was tolerant in this series. There was no patient develop opportunistic or systemic bacterial infection. Sirolimus is commended as a second-line treatment to treat intractable cervicofacial LMs after failure of traditional therapy. The intermittent administration regimen is efficacious to completely control symptoms and partially reduce residual lesions with good tolerance and limited side effects.