USE OF PORTAL RADIOGRAPHY TO INCREASE ACCURACY OF DOSE DELIVERY IN RADIATION THERAPY   总被引：1，自引：1，他引：0  

Margaret C.  McEntee  DVM  Donald E.  Thrall  DVM  PhD 《Veterinary radiology & ultrasound》1995,36(1):69-77

Port films were acquired for all radiation therapy patients (n = 132) treated over a thirteen month period to 1] assist in initial treatment field set-up on Day 1, 2] for quality assurance with a second port film taken on Day 7 of radiation therapy, and 3] as a means to document the radiation treatment field as a part of the patients permanent medical record. Port films were used for both patients treated with a definitive course of radiation (n = 97 patients), and those treated palliatively (n = 35 patients). The portal radiographs were valuable in terms of the initial set-up, and to correct for any positioning or other errors at the time of the one week recheck. Changes were made, based on the initial port film on Day 1, in 53% and 57% of treatment fields for palliative and definitive radiation patients, respectively. The changes made in both definitively and palliatively irradiated patients were usually in field position, an increase in field size to include all of the tumor, or a decrease in field size to spare normal tissue. Fewer changes were necessary based on the Day 7 recheck port films, but these day-7 rechecks are recommended for quality control. Based on the high frequency of changes introduced because of the initial port film findings, it is recommended that port films be incorporated on a routine basis in veterinary radiation therapy.  相似文献   

INTRAPERITONEAL VS. EXTRAPERITONEAL FLUID     

Donald E.  Thrall  DVM  PhD 《Veterinary radiology & ultrasound》1992,33(3):138-140

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Evaluation of clinical signs of disease, bronchoalveolar and tracheal wash analysis, and arterial blood gas tensions in 13 horses with chronic obstructive pulmonary disease treated with prednisone, methyl sulfonmethane, and clenbuterol hydrochloride.     

J L Traub-Dargatz  A O McKinnon  M A Thrall  R L Jones  W Bruyninckx  A M Blancquaert  D A Dargatz 《American journal of veterinary research》1992,53(10):1908-1916

We evaluated the efficacy of 3 treatments for chronic obstructive pulmonary disease in horses: prednisone (400 mg/horse, PO, daily; n = 7), methyl sulfonmethane (10 g/horse, PO, q 12 h; n = 6), and clenbuterol hydrochloride (0.4 mg/horse, PO, q 12 h; n = 7). A fourth group acted as controls (n = 6) and was not treated. The treatment period lasted 10 days. Each horse was a member of 2 different groups for 10 days, separated by an 18-day interval of no treatment. All horses were housed together in an outdoor pen without bedding. Horses were fed alfalfa/grass hay mix ad libitum from a large feeder. The same batch of hay was fed throughout the study. Multiple physical and laboratory variables were monitored prior to, during, and at the end of each 10-day trial period. Changes in lung sounds, respiratory effort, degree of anal movement, nasal discharge, temperature, respiratory rate, or heart rate were not significant. Changes in arterial blood gas tensions, tracheal wash or bronchoalveolar lavage cytologic findings, or phagocyte function were not significant. All horses were tachypneic and most were tachycardic. The median value for PaO2 was below normal for all horses. All tracheal wash and most bronchoalveolar lavage cytologic findings represented a suppurative response. Negative linear correlation was observed between PaO2 and degree of respiratory effort in these horses (eg, as PaO2 decreased, the degree of respiratory effort increased).  相似文献   

POSTOPERATIVE IRRADIATION OF SPINAL CORD TUMORS IN 9 DOGS     

Sheri  Siegel  DVM  Joe N.  Kornegay  DVM  PhD  Donald E.  Thrall  DVM  PhD 《Veterinary radiology & ultrasound》1996,37(2):150-153

Between 1985 and 1993, nine dogs with spinal cord tumors were treated postoperatively with cobaltradiation at North Carolina State University-Veterinary Teaching Hospital. Total doses ranged between 33.3–48.0 Gy given in 10–12 fractions of 3–4 Gy over a four week period. Five dogs were euthanized due to recurrence of the tumor or neurologic signs and two dogs were euthanized due tounrelated problems. Two dogs were alive but lost to follow-up at 12 and 25 months. Survival time ranged from 6.5–70.0 months. Median survival time (95% confidence interval) was 17 (12–70) months. Results of this study suggest decompressive surgery followed by irradiation can be an effective treatment for dogs with spinal cord tumors.  相似文献   

RADIOTHERAPY OF CANINE NON-TONSILLAR SQUAMOUS CELL CARCINOMA   总被引：1，自引：0，他引：1  

Tracy  LaDue-Miller  DVM  G. Sylvester  Price  DVM  PhD  Rodney L.  Page  DVM  MS  Donald E.  Thrall  DVM  PhD 《Veterinary radiology & ultrasound》1996,37(1):74-77

The records of 14 dogs treated with megavoltage radiation for non-tonsillar oral squamous cell carcinoma were reviewed to determine the efficacy of this treatment modality. Total radiation dose was either 48 or 57 Gray (Gy), while dose per fraction was either 3.0 or 4.0 Gy. Median disease free interval and survival were 365 and 450 days, respectively. Median disease free interval was shorter in dogs older than nine years (210 days) as compared with dogs less than or equal to nine years old (470 days), (p < .005). Median survival was shorter in dogs older than nine years (315 days) as compared with dogs less than or equal to nine years old (1080 days), (p < 0.02). Weight, stage, anatomic subsite, intraoral location, duration of disease, prior surgery, and number of radiation fractions did not appear to influence disease free interval or survival. Data presented herein suggest that survival in dogs with non-tonsillar squamous cell carcinoma receiving megavoltage radiation may be longer than that achieved with orthovoltage radiation or surgery. Megavoltage radiation appears to be an effective treatment for non-tonsillar oral squamous cell carcinoma in dogs. Further study is needed to determine the optimal time-dose sched-ule.  相似文献   

FELINE HYPERTHYROIDISM: EFFICACY OF TREATMENT USING VOLUMETRIC ANALYSIS FOR RADIOIODINE DOSE CALCULATION   总被引：3，自引：0，他引：3  

Lisa J.  Forrest  VMD  Catherine J.  Baty  DVM  Michael R.  Metcalf  DVM  MS  Donald E.  Thrall  DVM  PhD 《Veterinary radiology & ultrasound》1996,37(2):141-145

Hyperthyroidism was diagnosed in 80 cats with thyroid scintigraphy using technetium pertechnetate. These cats were subsequently treated with radioiodine using a modified fixed dose method based on the volume of hyperfunctioning thyroid tissue calculated from the pertechnetate scans. The medical records and thyroid scintigrams were evaluated retrospectively. Follow-up was obtained on the cats to evaluate treatment success. Several parameters were evaluated in an attempt to identify a difference between treatment success and failure. Cats that failed to become euthyroid after one dose of radioiodine had a significantly higher pretreatment serum thyroxine level, had a significantly larger volume of hyperfunctioning thyroid tissue on scintigrams, and cats receiving oral versus intravenous radioiodine were over represented. Based on our results we conclude: 1) the administration of a dose of radioiodine based solely on the volume of hyperfunctioning thyroid tissue as estimated from the pertechnetate scan may be inadequate for those patients with extremely elevated serum thyroxine levels or large thyroid glands, and 2) oral administration of radioiodine is not recommended for the treatment of feline hyperthyroidism.  相似文献   

Blood precipitate associated with intra-abdominal carboxymethylcellulose administration     

Burkhard MJ  Baxter G  Thrall MA 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1996,25(4):114-117

A precipitate was observed on the blood films of horses (15 of 16) and one cow given a peritoneal infusion of 1 % sodium carboxymethylcellulose (SCMC) solution to prevent abdominal adhesions. The intensity of the precipitate seen 2 to 3 days post-infusion strongly correlated with the administered dose of SCMC (range 0.96 to 11.7 ml/kg). The dose given was inversely correlated with bodyweight and the most prominent precipitates were seen in foals. The precipitate was observed as early as 24 hours and persisted for as long as 9 days after SCMC administration. Fibrinogen was the only hematological or biochemical parameter consistently abnormal in horses receiving SCMC, mild increases (500 to 700 mg/dl) were noted in 11/16 cases but did not correlate with SCMC administration.  相似文献   

What have we learned from studies of wild plant-pathogen associations?—the dynamic interplay of time,space and life-history     

J. J. Burdon  P. H. Thrall 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(3):417-429

The interplay of host and pathogen life history traits with disease epidemiology and the selective pressures exerted on hosts drives genetic change and the long-term coevolutionary trajectories of host-pathogen associations. Many studies have addressed various aspects of the ways in which hosts and their pathogens interact but have tended to focus on individual populations, on comparisons made at single points in time, or on broader comparisons that confound patterns from different epidemiological and evolutionary units. While such studies provide valuable information, their essentially ‘static’ snap-shot nature limits the ability to interpret the nature of the underpinning coevolutionary processes. An increasing number of long-term studies involving repeat sampling of multiple interaction demes distributed across space are giving insight into the complexity of the numerical and genetic dynamics of host and pathogen interactions. These illustrate: (a) the ephemerality of disease in individual populations in contrast to its predictability at the metapopulation scale; (b) the spatial and temporal dynamics of selection ‘hot-spots’, rates of extinction and recolonization; and (c) differences in coevolutionary dynamics among demes within a metapopulation. Such long-term studies further emphasise the interplay between life history traits, time and space, and the importance of developing a framework to classify the seemingly daunting diversity of host-pathogen associations.  相似文献   

THORACIC RADIOGRAPHIC FEATURES OF ANTICOAGULANT RODENTICIDE TOXICITY IN FOURTEEN DOGS     

Clifford R.  Berry  DVM  Anna  Gallaway  BVSc  Donald E.  Thrall  DVM  PhD  Carolyn  Carlisle  MVSc 《Veterinary radiology & ultrasound》1993,34(6):391-396

Thoracic radiographs and clinical records from 14 dogs with confirmed anticoagulant rodenticide toxicity were reviewed. Twelve of the 14 dogs were presented with a chief complaint of respiratory distress, and 12 had elevated prothrombin and activated partial thromboplastin times consistent with a coagulopathy secondary to a clotting factor deficiency. Thoracic radiographs of the 14 dogs were reviewed and abnomalities included increased mediastinal soft tissue opacity with extra and intrathoracic tracheal narrowing (4/14), increased mediastinal soft tissue opacity without tracheal narrowing (8/14), variable degrees of pleural effusion (13/14) and generalized, patchy interstitial/alveolar pulmonary infiltrates (8/14). Radiographic evidence of cardiomegaly and pulmonary artery abnormalities consistent with concurrent heartworm infestation were detected in one dog. In four dogs, dramatic tracheal narrowing was identified on the lateral thoracic radiograph caused by either mediastinal hemorrhage compressing the trachea or submucosal hemorrhage within the tracheal lumen. The trachea was displaced in a ventral direction in two dogs, and extra and intrathoracic luminal diameter narrowing was evident cranially in all four dogs. Two of these four dogs had soft tissue opacity within the dorsal trachea that extended from the larynx to the intrathoracic trachea. Twelve of the 14 dogs survived with standard treatment protocols utilizing injectable and oral vitamin K₁. One dog died from pancreatitis and disseminated intravascular coagulopathy. The other dog died soon after presentation due to severe, disseminated hemorrhage. Follow-up thoracic radiographs were made in four dogs that survived and showed resolution of the mediastinal, pleural and pulmonary changes within one to five days after the initiation of vitamin K₁ therapy.  相似文献   

FAILURE PATTERNS FOLLOWING COBALT IRRADIATION IN DOGS WITH NASAL CARCINOMA   总被引：1，自引：1，他引：0  

Donald E.  Thrall  DVM  PhD  Greta L.  Heidner  DVM†  Carol A.  Novotney  DVM  Margaret C.  McEntee  DVM†  Rodney L.  Page  DVM  MS† 《Veterinary radiology & ultrasound》1993,34(2):126-133

The pattern of tumor recurrence was assessed in 24 dogs receiving cobalt radiation therapy for nasal carcinoma. Dogs were evaluated using nasal cavity computed tomography prior to treatment, and at 1, 3, 6 and 12 months after treatment, and at 6-month intervals thereafter if still alive. Dogs were treated with various combinations of total dose, and fraction size. Total doses were normalized to equivalent doses given in 3.0 Gy fractions. The extent of tumor regression or duration of tumor control were not dependent on absolute total dose, normalized total dose, or tumor type. The median duration of local control in all dogs was 312 days. Marked tumor regression was observed in 11 of the 24 dogs. Median duration of local control was significantly longer in dogs with marked tumor regression in comparison to dogs without tumor regression; 389 vs. 161 days respectively. When tumor recurrence was documented in dogs having tumor regression, the location of the recurrence was in the nasal cavity. No tumor recurred in a sinus or periorbital region, and only one geographic miss was detected. Tumor recurrence in the irradiated volume, including dogs with and without marked regression, was documented in 13 of the 24 dogs. The high local failure rate, coupled with the recurrence pattern in these dogs, suggests there may be an opportunity for improvement in local control through use of shrinking field techniques.  相似文献