Intra-arterial cisplatin with or without radiation in limb-sparing for canine osteosarcoma.
METHODS
Forty-nine dogs with spontaneously occurring osteosarcoma underwent limb-sparing surgery after preoperative therapy consisting of intra-arterial cisplatin alone or intra-arterial cisplatin in combination with doses of radiation from 20-40 Gy in 10 fractions. All resections were marginal, and the defect was repaired with a cortical allograft.


RESULTS
Local tumor control was strongly influenced by the percent necrosis in the excised specimen. Overall, the estimated 1-year local recurrence rate was approximately 32% (by life-table estimate). Dogs with less than 75% necrosis had an estimated 1-year recurrence rate of 65%; those with greater than 75% necrosis had an estimated 1-year recurrence rate of 15% (P = 0.004, by log-rank test). Local recurrence was influenced by the radiation dose. Dogs receiving 28 Gy or less had an estimated 50% 1-year recurrence rate, and those receiving 32 Gy or more had an estimated 8% 1-year recurrence rate (P = 0.03, by log-rank test). Normal host bone more frequently became necrotic at doses of 36 Gy or more.


CONCLUSIONS
Intra-arterial cisplatin in combination with moderate doses of radiation (32 Gy) can achieve a high percent tumor necrosis while maintaining host bone viability. Survival was limited by distant metastasis but was lengthened by treatment compared with some earlier findings.
Withrow
S J
SJ
College of Veterinary Medicine, Colorado State University, Fort Collins.
Thrall
D E
DE
Straw
R C
RC
Powers
B E
BE
Wrigley
R H
RH
Larue
S M
SM
Page
R L
RL
Richardson
D C
DC
Bissonette
K W
KW
Betts
C W
CW
D000671:Amputation, Surgical / Q000662:veterinary; D000818:Animals; D001859:Bone Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000662:veterinary*; D002945:Cisplatin / Q000008:administration & dosage*; D003131:Combined Modality Therapy / Q000662:veterinary; D004285:Dogs; D005260:Female; D005552:Forelimb; D006811:Humerus; D007269:Injections, Intra-Arterial / Q000662:veterinary; D008297:Male; D012516:Osteosarcoma / Q000188:drug therapy / Q000532:radiotherapy / Q000662:veterinary*; D011879:Radiotherapy Dosage / Q000662:veterinary; D011884:Radius; D051381:Rats; D014457:Ulna
D002945:Cisplatin