Evaluation of strontium Sr 90 for the treatment of superficial squamous cell carcinoma of the nasal planum in cats: 49 cases (1990-2006).
OBJECTIVE
To determine progression-free and overall survival times of cats with squamous cell carcinoma (SCC) of the nasal planum following treatment with a single fraction of strontium Sr 90 ((90)Sr).


METHODS
Retrospective case series.


METHODS
49 cats with SCC of the nasal planum.


METHODS
Information including FIV infection status, diagnosis of SCC vs SCC in situ (ie, evidence that the tumor did or did not penetrate the epidermal basement membrane, respectively), (90)Sr dose and number of probe applications, treatment-related response and complications, and recurrence of SCC and new lesion development was obtained from medical records. The relationships of these variables with calculated progression-free and overall survival times were assessed.


RESULTS
Of 49 cats that underwent (90)Sr plesiotherapy (median dose, 128 Gy), 48 (98%) had a response to treatment and 43 (88%) had a complete response. Median progression-free and overall survival times were 1,710 and 3,076 days, respectively. Treatment complications were infrequent (4 [8%] cats) and mild. Following treatment, the SCC recurrence rate was 20% (10/49 cats); 16 (33%) cats developed new lesions in other locations. Overall survival time was significantly longer for cats with a complete response to treatment than for those with a partial response. None of the other variables evaluated had a significant effect on progression-free or overall survival time.


CONCLUSIONS
Treatment of cats with SCC of the nasal planum with a single fraction of (90)Sr appeared to be effective and well tolerated. Initial response to treatment was predictive of overall survival time.
Hammond
Genevieve M
GM
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Gordon
Ira K
IK
Theon
Alain P
AP
Kent
Michael S
MS
D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy / Q000662:veterinary*; D002371:Cat Diseases / Q000532:radiotherapy*; D002415:Cats; D018572:Disease-Free Survival; D004307:Dose-Response Relationship, Radiation; D005260:Female; D008297:Male; D009669:Nose Neoplasms / Q000532:radiotherapy / Q000662:veterinary*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013326:Strontium Radioisotopes / Q000627:therapeutic use*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D013326:Strontium Radioisotopes