Efficacy of Radiation Therapy for the Treatment of Sialocele in Dogs.

BACKGROUND: Sialocele is a collection of saliva that has leaked from a damaged salivary gland or duct and is surrounded by granulation tissue. Surgery is the recognized first-line treatment. Recurrence rate after surgery is 5-14%. Salivary gland tissue is very sensitive to radiation therapy (RT). HYPOTHESIS/OBJECTIVES: Radiation therapy will be useful for the treatment of sialocele. The aims were to characterize response rate and clinical course of dogs with sialocele treated with RT and to determine a starting dose for clinical use. ANIMALS: Eleven dogs with sialocele. METHODS: Retrospective study of response and outcome after RT. RESULTS: All dogs had cervical sialocele. Seven dogs (63.6%) were treated with 3 weekly fractions of 4 Gray (Gy); (total dose, 12 Gy). Three dogs (27.3%) received 4 fractions of 4 Gy (16 Gy) and 1 dog received 5 fractions of 4 Gy (20 Gy) on a Monday-Wednesday-Friday schedule. Six dogs (54%) achieved a complete response (CR), and 5 dogs (45%) achieved a partial response (PR). Three dogs had progression of their sialocele 2, 3, and 9 months after RT; all three had received 12 Gy initially and 2 received 2 additional fractions of 4 Gy (cumulative total dose, 20 Gy) and subsequently achieved remission for >2 years. CONCLUSIONS AND CLINICAL IMPORTANCE: Radiation therapy is useful for the treatment of recurrent sialocele refractory to surgical management and a minimum total dose of 16 or 20 Gy in 4 Gy fractions appears effective.

[Combined use of irradiation and DNA tumor vaccine to treat canine oral malignant melanoma: a pilot study]. / Kombinierte Anwendung von Strahlentherapie und DNS Tumor Vakzine zur Behandlung des oralen malignen Melanoms beim Hund: Eine Pilotstudie.

Melanoma is the most common oral tumor in dogs, characterized by rapid growth, local invasion, and high metastatic rate. The goal of this study was to evaluate the combination of radiation therapy and DNA tumor vaccine. We hypothesized, that the concurrent use would not increase toxicity. Nine dogs with oral melanoma were treated with 4 fractions of 8 Gray at 7-day intervals. The vaccine was given 4 times every 14 days, beginning at the first radiation fraction. Local acute radiation toxicities were assessed according to the VRTOG toxicity scoring scheme over a time period of 7 weeks. In none of the evaluated dogs, mucositis, dermatitis and conjunctivitis exceeded grade 2. In 3 dogs mild fever, lethargy, and local swelling at the injection site were seen after vaccine application. In conclusion, the concurrent administration of radiation therapy and vaccine was well tolerated in all dogs.

Multimodal therapeutic approach and interdisciplinary challenge for the treatment of unresectable head and neck squamous cell carcinoma in six cats: a pilot study.

Feline head and neck squamous cell carcinoma (SCC) is a loco-regional disease harbouring a poor prognosis. The complex anatomic location precludes aggressive surgical resection and tumours recur within weeks to few months. Response to chemotherapy and local control after radiation therapy has been disappointing. In this study, a multimodal approach including medical treatment (thalidomide, piroxicam and bleomycin), radiation therapy (accelerated, hypofractionated protocol) and surgery was attempted in six cats. Treatment was well tolerated. Three cats with sublingual SCC were alive and in complete remission at data analysis closure after 759, 458 and 362 days. One cat with laryngeal SCC died of renal lymphoma after 51 days and the other with maxillary SCC died of a primary lung tumour 82 days after diagnosis. In both cats, the SCC was in complete remission. Only one cat developed metastases after 144 days. These encouraging preliminary results merit further evaluation in future trials.

[New concepts in human oncology: is it possible to use them in veterinary medicine as well?]. / Neue Konzepte in der humanen Onkologie: Können sie in der Veterinärmedizin eingesetzt werden?

In human oncology, novel targeted therapy focusing on monoclonal antibodies and tyrosine kinase inhibitors has become an attractive anticancer strategy. The introduction of antiangiogenetic drugs and metronomic chemotherapy has also increased the therapeutic arsenal. Chemotherapy still plays a key role in the treatment of many tumors affecting dogs and cats. However, novel anticancer strategies (including tyrosine kinase inhibitors and monoclonal antibodies, as well as antiangiogenetic treatments) are becoming relevant in veterinary medicine, too. The goal of this review is to describe new therapeutic strategies for cancer treatment in veterinary medicine, including less well-known chemotherapeutic drugs.

Pulmonary abnormalities in dogs with leptospirosis.

BACKGROUND: Leptospirosis in dogs is a multiorgan disease affecting mostly kidneys and liver. OBJECTIVES: The objective was to characterize prevalence, clinical, and radiological features and outcome of dogs with leptospirosis and pulmonary abnormalities. ANIMALS: Fifty dogs with leptospirosis. METHODS: Medical records of dogs diagnosed with leptospirosis at the Small Animal Clinic, Berlin, were reviewed. Diagnosis was based on microscopic agglutination test, blood or urine polymerase chain reaction, and histopathology. Based on clinical and/or radiological signs, patients were grouped into dogs with lung abnormalities (group 1) or without (group 2). Severity of respiratory distress was scored as mild to moderate (grade 1) or severe (grade 2). Thoracic radiographs were scored based on pulmonary changes and location as grade 1 (caudal interstitial pattern), 2 (generalized mild to moderate reticulonodular interstitial pattern), or 3 (generalized severe reticulonodular interstitial pattern with patchy alveolar consolidations). Results of CBC and biochemistry were compared between groups. RESULTS: Thirty-five dogs had radiological pulmonary changes (grade 1: 5; grade 2: 14; grade 3: 16); 31 of them had pulmonary distress (grade 1: 13, grade 2: 18). Sixty-seven percent of the dogs with dyspnea grade 2 were mainly euthanized because of respiratory distress. Fifteen percent of the dogs with dyspnea grade 1 and 21% without clinical respiratory signs were euthanized because of acute renal failure or sepsis. CONCLUSIONS AND CLINICAL IMPORTANCE: In 70% of dogs with leptospirosis pulmonary changes were detected. Lung involvement represented a severe complication causing increased case fatality depending on the severity of respiratory distress.

A retrospective analysis of radiation therapy for the treatment of feline vaccine-associated sarcoma.

We retrospectively evaluated predictive prognostic factors in 73 cats with vaccine-associated sarcoma given postsurgical curative (n = 46, most with clean margins) or coarse fractionated radiotherapy (n = 27, most with either macroscopic disease or dirty margins). The former animals displayed a median survival of 43 months and a median progression free interval (PFI) of 37 months, the latter reached a median survival of 24 months and a median PFI of 10 months. In cats undergoing coarse fractionated therapy, factors predictive of a better outcome included lack of visible mass (n = 10) as opposed to macroscopic disease (n = 17, survival: 30 versus 7 months, P = 0.025; PFI: 20 versus 4 months, P = 0.01), adjuvant chemotherapy for gross disease (n = 5/17, survival: 29 versus 5 months, P = 0.04) and a smaller number of surgeries preceding radiation therapy (coeff = 0.41, P = 0.03). The Ki67 index was not predictive for survival. We concluded that postsurgical curative and coarse fractionated radiotherapy are effective legitimate options for managing vaccine-associated sarcomas.

Contrast-enhanced power and color Doppler ultrasonography of the pancreas in healthy and diseased cats.

BACKGROUND: The diagnosis of feline pancreatic disease is difficult, because clinical abnormalities and routine noninvasive diagnostic tests are unreliable. OBJECTIVE: The purpose of this study was to investigate by Doppler ultrasonography if vascularity and blood volume differs in the otherwise ultrasonographically normal and diseased feline pancreas. ANIMALS: Thirty-six client owned cats. METHODS: The pancreas was examined with B-mode and contrast-enhanced color and power Doppler ultrasonography. Doppler images were analyzed with a computer program: parameter fractional area represents a vascularity index and color-weighted fractional area assesses blood volume. RESULTS: Based on the B-mode findings, the pancreas was considered normal in 11 clinically healthy cats and diseased in 25 cats of which 4 were clinically healthy and 21 had clinical signs consistent with pancreatic disease. Histologic or cytologic samples were taken in all diseased pancreata. Fifteen samples were of diagnostic quality: purulent or mixed cellular inflammation (8), nodular hyperplasia (4), and neoplasia (3) were identified. Vascularity and blood volume for all Doppler methods was significantly higher in cats with pancreatic disease. Significantly higher Doppler values were detected with power Doppler than with color Doppler, and with postcontrast color and power Doppler than with precontrast Doppler technologies. CONCLUSION: Contrast-enhanced Doppler ultrasonography appears feasible in the feline pancreas. Significant differences were found between normal cats and those with evidence of pancreatic pathology. Further studies are needed to evaluate its use for the differentiation of pancreatic disorders and in cats suspected to have pancreatic disease but without B-mode ultrasonographic changes of the pancreas.

Contrast harmonic imaging characterization of canine splenic lesions.

BACKGROUND: Although B-mode ultrasound is very sensitive for the detection of splenic lesions, its specificity is low. Contrast harmonic imaging is used successfully to differentiate benign from malignant liver lesions in humans and dogs. HYPOTHESIS: Contrast harmonic imaging could be useful to differentiate benign and malignant splenic lesions in dogs. ANIMALS: Sixty dogs (clinical patients) with splenic abnormalities detected during abdominal ultrasonography. METHODS: A prospective study was performed with a Philips ATL 5000 unit for contrast pulse inversion harmonic imaging (mechanical index: 0.08, contrast medium: SonoVue). Perfusion was assessed subjectively and quantitatively. RESULTS: Cytology or histology identified 27 benign (hyperplasia, extramedullary hematopoiesis, hematoma) and 29 malignant (hemangiosarcoma, malignant lymphoma, malignant histiocytosis, mesenchymal tumors without classification, mast cell tumors, and others) lesions and 4 normal spleens. Except for 1 benign nodule, extensive to moderate hypoechogenicity was only seen in malignant lesions during wash-in, at peak enhancement, and during wash-out (P= .0001, odds ratios: 37.9 [95% CI 4.5-316.5], 66.4 [95% CI 8.0-551.1], and 36.9 [95% CI 4.4-308.4]). Although all but 1 benign lesion enhanced well and were mildly hypo-, iso-, or hyperechoic in comparison with the normal spleen during all blood pool phases, marked enhancement occurred both in benign as well as in malignant splenic lesions. Quantitative perfusion values did not differ significantly between benign and malignant lesions. CONCLUSIONS AND CLINICAL IMPORTANCE: Moderate to extensive hypoechogenicity clearly identifies canine splenic malignant lesions. In nodules with marked enhancement, contrast harmonic ultrasound is of limited value and histology is needed.

Radiographic examination and outcome in consecutive feline trauma patients.

Using univariate analysis, the correlation between signalment, history, outcome and radiographic diagnosis made on whole-body radiographs was investigated in 100 consecutive feline trauma patients of an urban clinic. The radiographic findings included: 53 thoracic injuries, 39 abdominal injuries, 34 pelvic injuries, 28 soft tissue injuries, 26 spinal injuries, and 19 cases with signs of hypovolemia. Only four radiographs were considered normal. Surgical intervention was carried out in 51 cases. Of the 100 cases, 73 survived, 23 were euthanatized, and four died. A significant positive correlation with euthanasia was found when compared to patient age (p=0.0059), abdominal trauma (P=0.0500), spinal fractures (P=0.0468), and soft tissue injuries (P=0.0175). A significant negative correlation with survival was found when compared to patient age (P=0.0358), abdominal trauma (P=0.0439), intraperitoneal free air (P=0.0041), and soft tissue injury (P=0.0288). The results of this study indicate that whole-body radiographs are useful in detecting injury in the thorax, abdomen, spine, pelvis and soft tissues, and are valuable in the diagnostic work-up of feline trauma patients.

Comparative biology of human and canine osteosarcoma.

Dogs with osteosarcoma provide an important model for the same disease in humans. In this report, the comparative nature of human and canine osteosarcoma including incidence and risk factors, clinical presentation and diagnosis, genetic abnormalities, biologic behaviour and prognostic factors, as well as treatment options are reviewed.

Histiocytic sarcomas in flat-coated retrievers: a summary of 37 cases (November 1998-March 2005).

Thirty-seven cases of histiocytic-like sarcomas (HLSs) in flat-coated retriever dogs were evaluated retrospectively. This tumour accounted for 36% of the malignant tumours seen in this breed during the study period. The median age at presentation was 8.2 years. Thirty-four dogs presented with a swelling or mass in a muscle group or surrounding a joint. The remaining three presented for rib (1), cutaneous (1) or primary splenic origin (1). A high rate of metastasis to local lymph nodes (45%), thorax (20%) and abdominal organs (20% confirmed) was seen. Overall metastastic rate by the time of death was 70%. The median survival for all dogs was 123 days. The most significant prognostic indicator was presence of distant metastasis at the time of diagnosis with median survival of 68 or 200 days, with or without metastasis, respectively. Chemotherapy and radiation therapy significantly improved survival. Dogs given chemotherapy survived a median of 185 versus 34 days for dogs that were not (P = 0.0008). Dogs treated with radiation survived a median of 182 versus 60 days for those that were not (P = 0.0282). Dogs receiving only palliative therapy survived a median of 17 versus 167 days in dogs receiving any kind of radiation, chemotherapy, surgery or combinations. A set protocol of radiation and CCNU (RTCCNU) induced minimal toxicity and provided a median survival of 208 versus 68 days for all other dogs. While this tumour carries a poor long-term prognosis in flat-coated retrievers, it is reasonable to treat these dogs for palliation of signs and extension of life.

Measurements of hypoxia ([(18)F]-FMISO, [(18)F]-EF5) with positron emission tomography (PET) and perfusion using PET ([(15)O]-H(2)O) and power Doppler ultrasonography in feline fibrosarcomas*.

Abstract The aim of this study was to evaluate if hypoxia in feline fibrosarcomas can be detected. This was done using positron emission tomography (PET), two hypoxia tracers and polarographic pO(2) measurements. Of the seven cats included, five received [(18)F]-fluoromisonidazole and two 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide. Perfusion was evaluated with [(15)O]-H(2)O (n = 4) and with contrast-enhanced power Doppler ultrasonography (n = 5). Hypoxia was detected in three cats. Polarographic pO(2) measurements did not confirm PET results. In the ultrasonographic evaluation, low vascularity and low perfusion were seen with a peripheral vascular pattern and no perfusion in the centre of the tumour. This was in contrast to the [(15)O]-H(2)O scans, where central perfusion of the tumour was also found. In conclusion, it appears that hypoxia exists in this tumour type. The presence of tumour necrosis and heterogeneous hypoxia patterns in these tumours may explain the found discrepancies between the applied techniques.

[Positron emission tomography: diagnostic imaging on a molecular level]. / Positronen-Emissions-Tomographie: Ein bildgebendes Verfahren auf molekularer Ebene.

In human medicine positron emission tomography (PET) is a modern diagnostic imaging method. In the present paper we outline the physical principles of PET and give an overview over the main clinic fields where PET is being used, such as neurology, cardiology and oncology. Moreover, we present a current project in veterinary medicine (in collaboration with the Paul Scherrer Institute and the University Hospital Zurich), where a hypoxia tracer is applied to dogs and cats suffering from spontaneous tumors. Finally new developments in the field of PET were discussed.

[Metastases of perianal gland carcinoma in a dog: palliative tumor therapy]. / Perianaldrüsenkarzinom-Metastasen bei einem Hund: Palliative Tumortherapie.

Palliative radiation therapy may provide significant relief in symptoms in pets with incurable cancer. Therapy is applied over a short period of time, using larger than normal fractional doses. Palliative radiation leads to minimal or no side effects. This case report describes the situation of a miniature poodle that was presented with severe dyschezia as well as fresh blood in the feces. The dog had a large abdominal mass which was diagnosed as lymph-node metastasis of a perianal gland carcinoma. Therapy included palliative radiation as well as chemotherapy. Six months after initial presentation the dog is free of clinical symptoms.

A review of Doppler sonography for the assessment of tumour vascularity.

During the past decade, the vascular biology of cancer has become a highly interesting research field. To assess tumour vascularity and perfusion, various strategies such as computed tomography, magnetic resonance imaging and positron emission tomography have been investigated. Over the last years, important advances have taken place in the Doppler technology which dramatically improved its ability to evaluate the vascular system, even small and deep vessels. Doppler sonography provides a non-invasive means to assess the extent and morphology of tumour vascularity. This information is clinically important regarding diagnosis, prognosis and response to treatment, particularly in connection with the development of novel angiogenesis inhibitors. This article describes the different Doppler technologies most commonly used in human and experimental animal oncology. Based on in vivo tumour models and extensive clinical experience in humans, their significance and potential clinical applications are illustrated. First clinical reports in veterinary medicine are also reviewed.

Radiotherapy of pituitary tumours in five cats.

Five cats tentatively diagnosed with pituitary adenoma (four cases) or pituitary carcinoma (one case), based on computed tomography (CT) or magnetic resonance imaging, were treated with radiotherapy. Electrons were applied in four cats and electrons and photons in the fifth. Ten to 12 fractions of 3.5 to 4.0 Gy each were delivered on a Monday/Wednesday/Friday schedule. The mean total dose applied was 39 Gy. No severe acute side effects to treatment were seen. Follow-up CT examination was performed in four cats; the mass had disappeared in one cat and remained stable or slightly decreased in size in the other three. The survival times were 5.5, 8.0, 15.0, 18.0 and 20.5 months, with two cats dying of causes unrelated to the tumour. Based on these cases, radiotherapy appears to be a valuable treatment option for feline pituitary tumours.