Objective—To evaluate efficacy of radiation for treatment
of incompletely resected soft-tissue sarcomas
Design—Prospective serial study.
Animals—48 dogs with soft-tissue sarcomas.
Procedure—Tumors were resected to < 3 cm3 prior
to radiation. Tumors were treated on alternate days
(three 3-Gy fractions/wk) until 21 fractions had been
administered. Cobalt 60 radiation was used for all
Results—Five-year survival rate was 76%, and survival
rate was not different among tumor types or
locations. Four (8%) dogs developed metastases.
Eight (17%) dogs had tumor recurrence after radiation.
Development of metastases and local recurrence
were significantly associated with reduced survival
rate. Median survival time in dogs that developed
metastases was 250 days. Median disease-free
interval for all dogs was 1,082 days. Median time to
recurrence was 700 days. Dogs that developed recurrence
after a prolonged period responded well to a
second surgery. Acute radiation toxicosis was minimal;
osteosarcoma developed at the radiation site in
Conclusion and Clinical Relevance—An excellent
long-term survival rate may be achieved by treating
soft-tissue sarcomas in dogs with resection followed
by radiation. Amputation is not necessary for longterm
control of soft-tissue sarcomas in limbs.
Development of metastases and recurrence of local
tumors after radiation treatment are associated with
decreased survival rate. Acute and delayed radiation
toxicosis was minimal with the protocol used in this
study. (J Am Vet Med Assoc 2000;217:205–210)
Objective—To evaluate response rate and duration of
malignant melanomas in dogs treated with carboplatin.
Animals—27 client-owned dogs with spontaneously
occurring measurable malignant melanomas.
Procedure—Records of dogs with melanomas treated
with carboplatin from October 1989 to June 2000
were reviewed. Carboplatin was administered IV at
doses of 300 or 350 mg/m2 of body surface area.
Response to treatment and evidence of drug toxicity
Result—Response to treatment could be evaluated in
25 dogs. Of those, overall response rate was 28%.
One dog had a complete response, 6 (24%) dogs had
a partial response (> 50% reduction in tumor burden).
Median duration of partial response was 165 days.
Eighteen dogs had stable disease (n = 9; 36%) or progressive
disease (9; 36%). Response to treatment
was significantly associated with carboplatin dose on
a milligram per kilogram basis (15.1 mg/kg [6.9 mg/lb]
of body weight vs 12.6 mg/kg [5.7 mg/lb]). Evidence
of gastrointestinal toxicosis could be assessed in 27
dogs. Mean body weight of 5 dogs that developed
gastrointestinal toxicosis was significantly less than
that of 22 dogs without gastrointestinal toxicosis (9.9
kg [21.8 lb] vs 19.3 kg [42.5 lb]).
Conclusions and Clinical Relevance—Carboplatin
had activity against macroscopic spontaneously
occurring malignant melanomas in dogs and should
be considered as an adjunctive treatment for microscopic
local or metastatic tumors. Gastrointestinal
toxicosis was associated with body weight. Because
small dogs are more likely to have adverse gastrointestinal
effects, gastrointestinal protectants should be
considered for these patients. (J Am Vet Med Assoc