Reduced risk of pneumonia after changes in anesthetic procedures for dogs receiving repeated anesthesia for radiation treatment

Radiation therapy requires repeated anesthetic administration to patients who often have multiple comorbidities contributing to an increased rate of anesthetic complications such as pneumonia. This is a retrospective observational study in which data were collected from 146 medical records of dogs receiving repeat anesthesia for radiation treatment from prior to management changes and compared to data from 149 cases treated after completion of management changes. The objective was to determine if changes in case management protocol that were put in place decreased the risk of pneumonia development among these patients. Management changes that were made included the following: decrease in anticholinergic and pure-mu opioid use, change in positioning during intubation and recovery, prophylactic treatment of nausea, timing of cuff inflation and deflation, and aseptic handling of intubation equipment. There was a significant association between diagnosis of pneumonia and the following: pre- vs. post-changes to protocol, presence of a neurologic tumor, presence of respiratory disease, presence of megaesophagus, and number of radiation fractions completed. Diagnosis of pneumonia did not vary significantly by age group, body weight category, or sex. In a multivariable logistic regression model that controlled for the effects of the three concurrent diseases and fractions completed, the odds of being diagnosed with pneumonia were approximately 10 times greater among dogs anesthetized prior to management changes (odds ratio = 9.9, 95% CI = 2.0-48.7, P = 0.005).

A case report of total skin photon radiation therapy for cutaneous epitheliotropic lymphoma in a dog

Background

Total skin electron beam radiation therapy (TSEBT) is an effective treatment for primary diffuse cutaneous lymphomas in humans. While several techniques exist, they all require significant commitment of staff time and resources. In veterinary medicine, canine-specific techniques and strategies have been adapted and delivered but deemed not “realistically” clinically implementable given the time commitment of over 2.5 h plus per fraction or have been relegated to palliative intent. Leveraging these technologies of helical tomotherapy and 3D printing, we developed and clinically implemented a radiotherapeutic treatment strategy for the management of medically refractory diffuse cutaneous lymphoma in the dog.

Case presentation

A 13.5-year-old female spayed Bichon Frise presented to the Oncology service at Texas A&M University, College of Veterinary Medicine due to the progression of diffuse cutaneous epitheliotropic lymphoma (CEL) that had failed medical management. Twenty-seven gray were delivered to the patient with a treatment time requirement under 40 min including real time monitoring of anesthesia during setup and treatment. A partial response was noticeable after four fractions and the tumor completely regressed progressively over the entire treated area by the end of therapy. A grade 1 lethargy, fatigue, weight loss, and oral mucositis and grade 2 alopecia, nail/claw changes, pruritus, scaling, anorexia, and diarrhea were noted during treatment. Additionally, a grade 3 thrombocytopenia developed after fraction eight requiring a treatment interruption of 6 weeks and prescription modification prior to treatment continuation and completion. From the beginning of total skin photon radiation therapy (TSPT) treatment until the time of the patient was euthanized unrelated to cutaneous epitheliotropic lymphoma (123 days), only one new lesion on the head was identified and confirmed by histopathology within the treated fields.

Conclusions

The proposed technique is an acceptable alternative to TSEBT that is actually clinically implementable within a palliative or definitive setting and clinical constraints, however further testing and refinement is needed to reduce hematological complications and to confirm and expand on preliminary findings.