Objective—To evaluate the characteristics and outcomes of dogs with stage I, II, III, or IV oral malignant melanoma treated by various types of radiotherapy.
Design—Retrospective case series.
Procedures—Medical records of dogs with oral malignant melanoma treated by radiotherapy (with or without adjunctive treatments) at a veterinary medical center between July 2006 and December 2012 were reviewed. Information regarding signalment, tumor location, disease stage, treatment protocols, adverse effects, and survival time were obtained from medical records and by telephone follow-up. Associations between variables of interest and outcome were analyzed.
Results—Dogs received orthovoltage x-ray (n = 68), megavoltage x-ray (39), or electron beam (4) radiotherapy. Adjunctive treatments included debulking surgery (n = 18), chemotherapy (39), or both (27). Median survival times for dogs with stage I, II, III, and IV melanoma were 758 days (n = 19), 278 days (24), 163 days (37), and 80 days (31), respectively, and differed significantly between dogs with stage I disease and those with all other disease stages. Among dogs with stage III melanoma, risk of death was significantly higher in those that received orthovoltage x-ray treatment than in those that received megavoltage x-ray treatment. Severe (primary or secondary) adverse effects were identified in 9 dogs.
Conclusions and Clinical Relevance—Median survival time was significantly longer for dogs with stage I oral malignant melanoma than for dogs with more advanced disease at the time of staging. The staging system used may be a useful tool for prognosis prediction in dogs undergoing similar treatment protocols for oral malignant melanomas.
To evaluate the effects of combining one-lung ventilation and carbon dioxide insufflation (OLV-CDI) on intrathoracic working space (determined by means of CT) during thoracoscopy in dogs and investigate conditions that could safely improve working space compared with OLV alone.
6 healthy Beagles.
Dogs were anesthetized, and right- or left-sided (n = 3/side) OLV was instituted. On the blocked side, a laparoscopic trocar sleeve was placed in the ninth intercostal space for CDI. CT was performed under 3 conditions: with OLV alone, with OLV-CDI at an intrapleural pressure (IPP) of 3 mm Hg, and with OLV-CDI at an IPP of 5 mm Hg. Working space volume (WSV), ventilation space volume (VSV), and thoracic cavity volume (TCV) were determined from CT images.
With OLV-CDI at an IPP of 3 or 5 mm Hg, WSV and TCV were significantly increased, compared with values obtained during OLV alone. With OLV-CDI at an IPP of 5 mm Hg, VSV and Spo2 were significantly decreased, compared with values obtained during OLV alone. Additionally, contralateral pneumothorax was observed in 4 dogs at an IPP of 5 mm Hg.
Combining OLV and CDI could provide a larger working space than OLV alone, even with an IPP of 3 mm Hg, in dogs of limited size. However, an evaluation of the effects on oxygenation and cardiovascular variables is needed before clinical use.