OBJECTIVES: I. Determine the maximum tolerated dose and dose limiting toxicities of high dose yttrium Y 90 monoclonal antibody MN-14 with or without doxorubicin plus peripheral blood stem cell rescue in patients with medullary thyroid cancer. II. Correlate organ and tumor dosimetry with toxicity and antitumor responses in these patients. III. Assess response and duration of response in these patients after this treatment.