Unexpected toxicity following use of gemcitabine as a radiosensitizer in head and neck carcinomas: a veterinary radiation therapy oncology group pilot study.
Gemcitabine (2',2'-difluorodeoxycytidine) was given intravenously twice weekly to 10 cats with oral squamous cell carcinoma and 15 dogs with nasal carcinoma undergoing radiotherapy as a radiosensitizing agent. The average total radiation dose was 50 Gy for dogs and 54 Gy for cats given Monday-Friday (planned dose of 54 and 57 Gy, respectively). Dogs received an average of five doses of gemcitabine beginning at 50 mg/m2, and cats received an average of five doses of gemcitabine beginning at 25 mg/m2. Twelve of 15 dogs and five of 10 cats required chemotherapy dose reduction or postponement because of hematologic or normal tissue toxicity. The results herein do not support the use of gemcitabine at the studied dose and schedule, as significant hematologic and local tissue toxicity was observed in the studied patients. Pharmacokinetic data are necessary to best define the efficacy and optimal dose and schedule of gemcitabine in combination with traditional radiotherapy.
LeBlanc
Amy K
AK
Florida Veterinary Specialists, 3000 Busch Lake Blvd., Tampa, FL 33614, USA. aleblanc@utk.edu
LaDue
Tracy A
TA
Turrel
Jane M
JM
Klein
Mary Kay
MK
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000662:veterinary*; D002371:Cat Diseases / Q000188:drug therapy* / Q000532:radiotherapy; D002415:Cats; D003131:Combined Modality Therapy; D003841:Deoxycytidine / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*; D004283:Dog Diseases / Q000188:drug therapy* / Q000532:radiotherapy; D004285:Dogs; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D011829:Radiation Dosage; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage* / Q000009:adverse effects; D000093542:Gemcitabine
D011838:Radiation-Sensitizing Agents; D003841:Deoxycytidine; D000093542:Gemcitabine