Background: Indium-111 labeled antiferritin targets 95% of all Hodgkin's disease lesions with a diameter of 1 cm or more. Subsequent treatment with yttrium-90 labeled antiferritin secures a high response rate in patients with recurrent Hodgkin's disease.
Methods: A total of 87 patients were entered on one of three different yttrium-90 labeled antiferritin protocols. Recurrences after yttrium-90 treatment were analyzed. Nine patients were retreated with involved external beam radiation fields, selected with the help of indium-111 labeled antiferritin.
Results: In single-agent yttrium-90 antiferritin studies, a response rate of more than 60% was found, with an average response duration of 6 months. One-third of the patients had recurrences in previously uninvolved areas. Repeat indium antiferritin scintigraphy allowed for the selection of new radiation fields for recurrences. In-field disease control was obtained for a median of 8 months, but new recurrences in new areas occurred. Chemotherapy or radiation therapy given immediately before antiferritin decreased tumor targeting with indium-111 labeled antiferritin.
Conclusions: Recurrences after radiolabeled antiferritin treatment are not due to radioresistant Hodgkin's disease. In contrast, Hodgkin's disease less than 1 cm in diameter is not targeted and not controlled by radiolabeled antiferritin. New multimodality regimens with a higher therapeutic ratio are needed for treatment of Hodgkin's disease with curative intent. Radiolabeled antiferritin can be incorporated in such regimens to secure better control of bulky Hodgkin's disease (>1 cm in diameter), but it should be given before chemotherapy or radiation therapy.