Radiation therapy for oral melanoma in dogs: A retrospective study

Abstract

Our retrospective study evaluated the survival of 24 dogs with unresectable malignant melanoma treated with radiation therapy. Fifteen dogs were treated with radiation therapy (RT) and chemotherapy (CT), five with surgery followed by RT and CT, three with palliative RT, and one with electrochemotherapy associated with RT. All dogs were treated with an orthovoltage Stabilipan I. The protocol used was three or four weekly fractions of 8 Gy. Carboplatin was administered every 21 days, a total of four times. Five percent of dogs were classified as having stage I melanoma, 17% as stage II, 50% as stage III, and 17% as stage IV. Sixty-four percent had a partial response to treatment, 29% achieved complete remission, and 7% remained in a stable disease state. The mean survival time was 390 days for stage I, 286 days for stage II, 159 days for stage III, and 90 days for stage IV. We concluded that radiation therapy can be considered a viable alternative for the palliative treatment of canine oral melanoma.

Comparative Mathematical Radiotherapy of Some Dog and Human Cancers

“…Exposure to weekly radiation of 8 Gy with carboplatin every 21 days for 4 times resulted in mean survival time (390 days) for stage I, stage II (1, 286 days), stage III (159 days) and stage IV (90 days) respectively. Hence radiotherapy is a viable palliative treatment of canine oral melanoma [43]. But acute radiation side-effects are completely healed 4-week post radiation treatment in nontonsillar squamous cell carcinoma [44].…”

“…Combination of doxorubicin, cisplatin vinblastine or cyclophosphamide with radiotherapy of tonsillar squamous carcinoma of dog yielded a favourable higher rate of therapeutic response and signi cantly longer survival times [54]. But radiotherapy is a viable alternative for the palliative treatment of canine oral melanoma [43], in spite of the fact that hypoxia has negative in uence on determining response to conventional therapy [56], suggesting that substantial differences in intrinsic radio-sensitivity exist in canine cancers [57]. Fluorodeoxyglucose (FDG)/PET is an effective imaging technique for lymph mode staging of locally advanced cervical carcinoma with negative computed tomography (CT) ndings, despite PET-CT could customize and guide brachytherapy planning [58].…”

Treatment of Canine Oral Melanomas: A Critical Review of the Literature

“…Two of the studies in which RT was used with CT as an adjunctive included a control group that received only RT to evaluate the effect of CT in combination with RT, although the RT-only groups were small ( Table 4 ) [ 50 , 51 ]. Three studies, were retrospective case series [ 52 , 53 , 54 ].…”

“…Total Gys varying from 24 to 50 Gy, depending on study design and intention with therapy. Carboplatin was the most commonly used systemic chemotherapeutic, followed by cisplatin and only one study used melphalan [ 50 , 51 , 52 , 54 ]. Cisplatin was used as a local chemotherapeutic in one study [ 53 ].…”

Current Status of Canine Melanoma Diagnosis and Therapy: Report From a Colloquium on Canine Melanoma Organized by ABROVET (Brazilian Association of Veterinary Oncology)

“…The high rate of distant metastasis (44-58%) remains the significant limiting factor for curative intention treatment of canine oral melanoma (34,37,38). The author Cunha et al (39) evaluated the survival of 24 dogs with oral melanoma treated with orthovoltage radiotherapy. The mean age and standard deviation was 13 ± 2.6 years and the overall response rate was 93%, including 64% partial (one stage I, one stage II, seven stage III, and one stage IV) and 29% complete tumor responses (one stage…”