EXHIBIT 23.1 ------------ CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this Form S-3 Registration Statement of our report dated March 31, 1998 included in CYTOGEN Corporation's Form 10-K/A for the year ended December 31, 1997, and to all references to our Firm included in this Registration Statement. ARTHUR ANDERSEN LLP Philadelphia, PA April 9, 1998 33