MAXILLECTOMY AND TARGETED RADIONUCLIDE THERAPY WITH SM-153-EDTMP IN ARECURRENT CANINE OSTEOSARCOMA

An eight-year-old dog with a local relapse of an osteosarcoma was trea ted with partial maxillectomy and systemic radionuclide therapy that i nvolved two injections, 43 and 45 megabecquerels per kg bodyweight of the bone-seeking agent samarium-153-ethylenediaminetetramethylene phos phonic acid (Sm-153-EDTMP), 15 weeks apart. A transient drop in white blood cell count and platelet count was observed following each Sm-153 -EDTMP treatment. Follow-up 21 months after surgery revealed no eviden ce of local recurrence or metastases. The dog was in excellent conditi on, suffering only minor sequelae from the surgical procedure. Compare d with historical controls treated with surgery alone, the combination of surgery and systemic radionuclide therapy seems a promising strate gy for the treatment of canine osteosarcoma.