Efficacy of sirolimus in the treatment of microcystic lymphatic malformation of the tongue

Sirolimus for Pediatric Cervicofacial Lymphatic Malformation: A Systematic Review and Meta-Analysis

OBJECTIVE

This study is a systematic review and meta-analysis of the efficacy and safety of sirolimus in the management of pediatric cervicofacial lymphatic malformations (LMs).

DATA SOURCES

EMBASE, Medline, Scopus, and Cochrane databases were searched, along with the reference list of all included articles.

REVIEW METHODS

The study protocol was registered with PROSPERO and a systematic literature search strategy was designed and conducted with the aid of a medical librarian. All studies including case reports were included, with pooled analysis of raw data. A meta-analysis was conducted of magnetic resonance imaging (MRI), clinical, and airway outcomes.

RESULTS

Thirteen case series and five individual case reports were included. Meta-analysis showed 78% (95% CI 57%-94%) of 62 patients had a reduction in LM volume, on MRI criteria, by 20% or more, and 32% (95% CI 11%-57%) had a reduction of 50% or more. Further meta-analysis showed 97% (95% CI 88%-100%) of 78 patients reported some clinical improvement on sirolimus. Sirolimus may be of particular value in management of airway LMs; out of 27 tracheostomy-dependent patients, meta-analysis showed 33% (95% CI 1%-78%) were decannulated after starting sirolimus. Individual patient meta-analysis on 24 individuals showed a statistically significant better response to sirolimus when initiated under the age of 2 years.

CONCLUSION

This review and meta-analysis support the efficacy of sirolimus in pediatric LMs of the head, neck, and airway. A large multi-center trial is needed to further explore its role and limitations. Laryngoscope, 134:2038-2047, 2024.

Medical Therapeutics for the Treatment of Vascular Anomalies: Part 3

The discovery of inherited and somatic genetic mutations, along with advancements in clinical and scientific research, has improved the understanding of vascular anomalies and changed the treatment paradigm. With the aim of minimizing the need for invasive procedures and improving disease outcomes, molecularly targeted medications and anti-angiogenesis agents have become important as both adjuncts to surgery, and increasingly, as the primary treatment of vascular anomalies. This article highlights the commonly used and emerging therapeutic medications for nonmalignant vascular tumors and vascular malformations.

Alpelisib for the treatment of PIK3CA-related head and neck lymphatic malformations and overgrowth

PURPOSE

PIK3CA-related overgrowth spectrum (PROS) conditions of the head and neck are treatment challenges. Traditionally, these conditions require multiple invasive interventions, with incomplete malformation removal, disfigurement, and possible dysfunction. Use of the PI3K inhibitor alpelisib, previously shown to be effective in PROS, has not been reported in PIK3CA-associated head and neck lymphatic malformations (HNLMs) or facial infiltrating lipomatosis (FIL). We describe prospective treatment of 5 children with PIK3CA-associated HNLMs or head and neck FIL with alpelisib monotherapy.

METHODS

A total of 5 children with PIK3CA-associated HNLMs (n = 4) or FIL (n = 1) received alpelisib monotherapy (aged 2-12 years). Treatment response was determined by parental report, clinical evaluation, diary/questionnaire, and standardized clinical photography, measuring facial volume through 3-dimensional photos and magnetic resonance imaging.

RESULTS

All participants had reduction in the size of lesion, and all had improvement or resolution of malformation inflammation/pain/bleeding. Common invasive therapy was avoided (ie, tracheotomy). After 6 or more months of alpelisib therapy, facial volume was reduced (range 1%-20%) and magnetic resonance imaging anomaly volume (range 0%-23%) were reduced, and there was improvement in swallowing, upper airway patency, and speech clarity.

CONCLUSION

Individuals with head and neck PROS treated with alpelisib had decreased malformation size and locoregional overgrowth, improved function and symptoms, and fewer invasive procedures.

Sirolimus in the Treatment of Microcystic Lymphatic Malformations: A Systematic Review

Background: Genetic alterations in lymphatic development can lead to microcystic lymphatic malformations (micro LMs). LMs can have both microcystic and macrocytic components or be exclusively one or the other. LMs can result in serious, sometimes life-threatening, sequelae. Absent consensus guidelines, treatment has been largely empiric. Recent advances in our understanding of the pathogenesis of micro LMs have provided a foundation for novel therapeutic approaches. This review examines clinical data over the last 10 years on the role of sirolimus, an inhibitor of the PI3K/AKT/mTOR signaling pathway implicated in micro LM development, in the treatment of micro LM. Methods and Results: Systematic review of published clinical studies from January 1, 2011, to July 15, 2021, using the PubMed, Google Scholar, and Cochrane Reviews databases, and utilizing delimiters to focus specifically on sirolimus in the treatment of micro LM. A total of 16 studies were identified (13 case studies or case reviews; 3 prospective) that included 52 subjects treated with topical (n = 15) or oral (n = 37) sirolimus for micro LM. Clinically meaningful, long-term improvement (up to 3 years) was noted in 92% (46/50), mostly previously treated subjects. Sirolimus yielded improvements in key manifestations such as lymphatic leakage, bleeding, vesicle bulk, pain, and skin discoloration. Some subjects experienced a rapid onset of effect (within 2 weeks). No unexpected adverse events were seen. Conclusion: Sirolimus appears to be an effective and safe option in the management of cutaneous and complex micro LM. However, prospective, controlled trials are clearly needed to accurately elucidate the benefits and risks of sirolimus in the management of micro LM. ClinicalTrials.gov Identifier: NCT05050149.

Efficacy of sirolimus in children with lymphatic malformations of the head and neck

Purpose

Children with extensive lymphatic malformations of the head and neck often suffer from functional impairment and aesthetic deformity which significantly affect the quality of life and may be life-threatening. Treatment with sirolimus has the potential to improve symptoms and downsize lymphatic malformations. This systematic review summarizes the current information about sirolimus treatment of lymphatic malformations of the head and neck in children, its efficacy and side effects.

Methods

A systematic search of the literature regarding studies on sirolimus treatment of children with lymphatic malformations of the head and neck was performed in PubMed, Embase, and Google Scholar up to July 2021 with the search terms “lymphatic malformation”, “lymphangioma”, “cystic hygroma”, “low-flow malformation”, “sirolimus”, “rapamycin”, “mTOR inhibitor” and “children”.

Results

In all, 28 studies including 105 children from newborn to 17 years treated with sirolimus for lymphatic malformations of the head and neck were analyzed. The most frequent initial dose was 0.8 mg/m² per dose, twice daily at 12-h interval. The target blood level differed between studies, 10–15 ng/mL and 5–15 ng/mL were most often used. More than 91% of the children responded to sirolimus treatment which lasts from 6 months to 4 years. Typical side effects were hyperlipidemia, neutropenia and infections.

Methods

Sirolimus could be an effective treatment for children with large complicated lymphatic malformations of the head and neck. As not all patients will benefit from treatment, the decision to treat sirolimus should be made by a multidisciplinary team.

Oral manifestations and dental care management of a young patient with lymphangioma of the tongue: A case report

Children with lymphangioma of the tongue may require a close collaboration between physician and dentist to establish preventive, conservative approaches, and eradicate any sources of dental infections before undertaking immunosuppressive therapy.

Efficacy of Initial Sirolimus Therapy for 27 Patients with Intractable Lymphatic Malformations

OBJECTIVE/HYPOTHESIS

To evaluate the efficacy of initial sirolimus therapy in the treatment of intractable head and neck lymphatic malformations (LMs) in children.

STUDY DESIGN

Prospective open-label study.

METHODS

In this study, Twenty-seven children diagnosed with LMs were given oral sirolimus as primary treatment over a minimum 6-month trial. The major parameter to evaluate therapeutic outcome was percentage of lesion volume change compared with baseline. Average serum sirolimus concentrations, and adverse side effects, were monitored throughout the study period.

RESULTS

Fifteen girls and twelve boys, average age 27 months (16 days-171 months), constitute the study group. Treatment was deemed effective for twenty-three participants, judged as fair in seven, good in nine, and excellent in seven. Two patients had minimal improvement, and two had increased volume to some degree. Effectiveness differed among LMs subtypes with responsiveness of macrocystic LMs exceeding that of microcystic LMs (P < .05). Adverse drug reactions totaled 27 events in ten patients, the majority being mild with upper respiratory infections being most common.

CONCLUSIONS

Sirolimus as initial therapy is effective in decreasing lesion volume in intractable LMs in head and neck region, especially in macrocystic subtypes. Although most cases cannot be completely cured, side effects are few and tolerable.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1902-1908, 2021.