Background: Nonmalignant vascular anomalies (VA) comprise a heterogeneous spectrum of conditions characterized by aberrant growth or development of blood and/or lymphatic vessels and can cause significant morbidity. Little is known about outcomes after radiotherapy in pediatric and young adult patients with nonmalignant VA.
Methods: Thirty patients who were diagnosed with nonmalignant VA and treated with radiotherapy prior to 2017 and before the age of 30 were identified. Clinical and treatment characteristics and outcomes were recorded.
Results: Median age at first radiotherapy was 15 years (range 0.02-27). Median follow-up from completion of first radiotherapy was 9.8 years (range 0.02-67.4). Lymphatic malformations (33%), kaposiform hemangioendothelioma (17%), and venous malformations (17%) were the most common diagnoses. The most common indication for first radiotherapy was progression despite standard therapy and/or urgent palliation for symptoms (57%). After first radiotherapy, 14 patients (47%) had a complete response or partial response, defined as decrease in size of treated lesion or symptomatic improvement. After first radiotherapy, 27 (90%) required additional treatment for progression or recurrence. Long-term complications included telangiectasias, fibrosis, xerophthalmia, radiation pneumonitis, ovarian failure, and central hypothyroidism. No patient developed secondary malignancies. At last follow-up, three patients (10%) were without evidence of disease, 26 (87%) with disease, and one died of complications (3.3%).
Conclusions: A small group of pediatric and young adult patients with nonmalignant, high-risk VA experienced clinical benefit from radiotherapy with expected toxicity; however, most experienced progression. Prospective studies are needed to characterize indications for radiotherapy in VA refractory to medical therapy, including targeted inhibitors.
Keywords: Gorham Stout disease; kaposiform hemangioendothelioma; lymphatic malformation; palliation; venous malformation.
© 2021 Wiley Periodicals LLC.