Answer:
Reports of treatment with interferon have been encouraging, and it is recommended for patients who are refractory to corticosteroids or laser treatment. Two possible mechanisms of action have been postulated. One theory is that interferon inhibits proliferation of endothelial cells by stimulating the release of the enzyme 2’,5’-oligoadenylate synthetase. The other theory is that interferon opposes fibroblast growth factor, a potent angiogenic source. In contrast to steriods, which tend to work within the first 7-10 days of therapy, interferon may take 1 to 2 months to demonstrate any beneficial results. During the first 48 hours of treatment, patients may develop significant hemodynamic changes especially if they have massive lesions or have significant circulatory compromise. For this reason, some recommend ICU monitoring for the first 2 days of treatment. Milder side effects include low-grade fever and flu-like symptoms during the first 7 to 10 days of therapy. Neutropenia has been reported but infectious complications related to interferon therapy have been non-existent.
Radiation therapy has been shown to be very effective against proliferating hemangiomas and was very popular during the first half of the 20th century until its many associated complications became apparent. Side effects include burns, skin changes, damage to breasts, gonads, ocular lens, epiphyses, and thyroid, with increased risk of thyroid, parathyroid, and salivary gland cancers as well as radiation-induced angiosarcoma. It is currently recommended for use only as a last resort in life-threatening hemangiomas unresponsive to other treatment modalities including surgery.