OBJECTIVE To assess outcomes, factors associated with survival time, and radiation-induced toxicoses in dogs treated for nasal tumors with curative-intent stereotactic body radiation therapy (SBRT).
DESIGN Retrospective case series.
ANIMALS 28 client-owned dogs.
PROCEDURES By use of a 6-MV linear accelerator, dogs were treated with SBRT (3 consecutive-day fractions of 9 or 10 Gy or once with 1 fraction of 20 Gy). Data regarding adverse effects, outcomes, and survival times were obtained from the medical records.
RESULTS The median survival time to death due to any cause was 388 days. Of the 24 dogs known to be dead, 14 (58%) died or were euthanized because of local disease progression. Acute radiation-induced adverse effects developed in the skin (excluding alopecia) in 26% (6/23) of dogs and in the oral cavity in 30% (7/23) of dogs. Acute ocular adverse effects included discharge in 26% (6/23) of dogs and keratoconjunctivitis sicca in 4% (1/23) of dogs. Among the 22 dogs alive at > 6 months after SBRT, 4 (18%) developed a unilateral cataract; 4 (18%) developed other complications that may have been late-onset radiation toxicoses (excluding leukotrichia and skin hyperpigmentation).
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dogs treated with SBRT had outcomes comparable to those reported for dogs with nasal carcinomas and sarcomas that undergo conventionally fractionated radiation therapy. Administration of SBRT was associated with a comparatively lower frequency of acute radiation-induced adverse effects. For SBRT and conventionally fractionated radiation therapy, the frequencies of serious late-onset adverse effects appear similar.
Objective—To measure respiratory motion of the thoracic wall region in dogs using a real-time motion tracking system and compare the amount of respiratory motion between dogs positioned with and without a vacuum-formable cushion.
Procedures—Dogs were anesthetized and positioned in sternal and dorsal recumbency with and without a vacuum-formable cushion. Three-dimensional movement of anatomic landmarks was measured with a real-time motion capture system that tracked the locations of infrared light–emitting diodes attached externally to the dorsal or ventral and lateral aspects of the thoracic wall.
Results—Dogs positioned in sternal recumbency had significantly less cranial-to-caudal and left-to-right respiratory motion at the lateral aspect of the thoracic wall, compared with dogs positioned in dorsal recumbency, whether or not a cushion was used. For dogs treated in sternal recumbency, use of a cushion significantly increased the peak displacement vector (overall movement in 3-D space) for 3 of 4 marker locations on the dorsal thoracic wall. As respiratory rate increased, respiratory motion at the lateral and ventral aspects of the thoracic wall decreased when data for all dogs in dorsal recumbency were evaluated together.
Conclusions and Clinical Relevance—Associations between respiratory rate and respiratory motion suggested that the use of rapid, shallow ventilation may be beneficial for dogs undergoing highly conformal radiation treatment. These results provide a basis for further research on respiratory motion in anesthetized dogs.
The objectives of this study were to investigate scattered radiation doses to the hands of equine workers holding the cassette and the x-ray tube by hand, for both limb and vertebral column studies, and to compare the scattered radiation attenuation of lead with radiation protection lead-free gloves. Radiation doses to the hands of the cassette holder in the primary beam were also investigated.
A whole-body horse cadaver.
A portable x-ray unit was used to simulate 6 radiographic study types in the horse cadaver. Doses were measured with no shielding and, for cassette holders, with the ion chamber enclosed in a lead glove and a lead-free glove. Thirty exposures were performed for each study view and condition (n = 1,920).
Mean scattered doses to x-ray unit operators were higher than doses to cassette holders for ungula (hoof), thoracic vertebrae, and lumbar vertebrae studies, whereas doses to cassette holders were higher than doses to x-ray tube operators for studies of the metacarpophalangeal joint (fetlock) and tarsus (hock). Doses did not differ for the stifle joint. Mean percentage decrease in scattered radiation dose was 99.58% with lead gloves and 98.9% with lead-free gloves.
X-ray tube operators can be exposed to equal or higher scattered radiation doses to the hand as cassette holders. Lead-free hand shielding should only be considered as an alternative to lead gloves if their lighter weight increases frequency of use by workers.