Mifumi Kawabe

Outcomes of dogs undergoing radiotherapy for treatment of oral malignant melanoma: 111 cases (2006–2012)

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. ANIMALS 111 dogs. 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.

Canine tumor development and crude incidence of tumors by breed based on domestic dogs in Gifu Prefecture

We analyzed the status of tumor development in dogs by breed based on tumor cases that presented to the Department of Veterinary Pathology of the Gifu University for diagnostic examinations over eight years (2005–2012). We also calculated the crude incidence of tumors in dogs by breed based on the results of a survey conducted in 2011 in Gifu Prefecture. The most common sites of tumor development included the skin, digestive organs and mammary glands. Smaller dogs showed a tendency to have a higher incidence of breast tumors. We thus identified dog breeds with a higher crude incidence of tumors (Bernese mountain dog, golden retriever, corgi, etc.) and those with a lower crude incidence of tumors (Pomeranian, poodle, Chihuahua, etc.). Unlike the current trends for domestic dogs in the US and Europe, Japan has a higher number of small dogs as pets; it is therefore necessary to develop a policy for canine cancer specific to Japan.

Computed Tomographic Evaluation of Presumptively Normal Canine Sternal Lymph Nodes

The sternal lymph nodes receive drainage from a wide variety of structures in the thoraco-abdominal region. Evaluation of these lymph nodes is essential, especially in cancer patients. Computed tomography (CT) can detect sternal lymph nodes more accurately than radiography or ultrasonography, and the criteria of the sternal lymphadenopathy are unknown. The purpose of this retrospective study was to describe the CT characteristics of the sternal lymph nodes in dogs considered unlikely to have lymphadenopathy. The ratio of the short axis dimension of the sternal lymph nodes to the thickness of the second sternebra was also investigated. At least one sternal lymph node was identified in each of the 152 dogs included in the study. The mean long axis and short axis dimensions were 0.700 cm and 0.368 cm, respectively. The mean ratio of the sternal lymph nodes to the second sternebrae was 0.457, and the 95% prediction interval ranged from 0.317 to 0.596 (almost a fixed value independent of body weight). These findings will be useful when evaluating sternal lymphadenopathy using CT.

Profiling of plasma metabolites in canine oral melanoma using gas chromatography-mass spectrometry

Malignant melanoma is one of the most common and aggressive tumors in the oral cavity of dog. The tumor has a poor prognosis, and methods for diagnosis and prediction of prognosis after treatment are required. Here, we examined metabolite profiling using gas chromatography-mass spectrometry (GC-MS) for development of a discriminant model for evaluation of prognosis. Metabolite profiles were evaluated in healthy and melanoma plasma samples using orthogonal projection to latent structure using discriminant analysis (OPLS-DA). Cases that were predicted to be healthy using the OPLS discriminant model had no advanced lesions after radiation therapy. These results indicate that metabolite profiling may be useful in diagnosis and prediction of prognosis of canine malignant melanoma.

Three-dimensional conformal radiation therapy for inoperable massive hepatocellular carcinoma in six dogs.

OBJECTIVES To evaluate the activity and tolerability of three-dimensional conformal radiation therapy (3D-CRT) in dogs with massive hepatocellular carcinoma. MATERIALS AND METHODS Six dogs with massive hepatocellular carcinoma that were ineligible for surgical resection or with owners who declined surgical resection, and underwent 3D-CRT were retrospectively reviewed. 6 to 10 Gy per fraction was prescribed at isocentre of planning target volume to a total dose of 18 to 42 Gy with 1 to 2 fractions per week for a total of 3 to 7 fractions. Follow-up examinations included physical examination, contrast-enhanced CT scan and blood analysis (complete blood count, electrolytes and serum biochemical panel). RESULTS The median follow-up time after 3D-CRT was 534 (range, 281 to 1057) days. An objective response was observed in five of six cases. Radiation-induced liver disease developed in one dog but was asymptomatic and reversible. Toxicity was not noted in any other dog. CLINICAL SIGNIFICANCE 3D-CRT appears to be a viable treatment option for dogs with inoperable massive hepatocellular carcinoma.

Body surface area measurement in laboratory miniature pigs using a computed tomography scanner.

The body surface area (BSA) of an organism is an important parameter for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying a constant by the power of the body weight (BW). Recently, the use of miniature pigs in non-clinical studies for medical drugs or devices has gradually been increasing. However, verification of their BSA is not as yet sufficient. In this study, we measured the BSAs of 40 laboratory miniature pigs (11 males and 9 females of Göttingen minipig and 14 males and 6 females of Nippon Institute for Biological Science [NIBS] miniature pig) by analyzing computed tomography (CT) images, since measurements using a CT scanner were expected to more precisely determine BSA than classical measuring techniques. The measurement results showed the BSAs of the 20 Göttingen minipigs to range from 0.4358 to 0.8356 m(2) (the working BW range: 12.7-37.0 kg) and 20 NIBS miniature pigs to range from 0.2906 to 0.8675 m(2) (the working BW range: 7.9-41.5 kg). Since accuracy and reproducibility were confirmed by measuring the surface area of an acrylic cuboid, we concluded the measurement method employed in this study to be very reliable. We propose the following estimating formula for BSA of laboratory miniature pigs: 100 × BSA [m(2)] = 7.98 × BW [kg](2/3).

Gastro Jejunal Inner Lumen Bypass Device Inhibits the Growth of Pigs

The EndoBarrier has a weak point caused by a Teflon membrane, which completely inhibits the movement of water and food. We developed a new type of gastro jejunal inner lumen bypass device (GJB) using an artificial net that has a hole instead of a membrane. We inserted a net in the gastric antrum-duodenum–jejunum via open laparotomy. The growth of pigs with long nets was suppressed compared with the sham operation. However, there were no differences in blood biochemistry or anatomical findings at autopsy between the groups. As a result, GJB can control the growth of pigs without requiring dietary restriction.

Metastatic diagnosis of canine sternal lymph nodes using computed tomography characteristics: A retrospective cross‐sectional study

The accurate evaluation of sternal lymph nodes (StLNs) is critical for the staging of canine thoraco-abdominal tumours. Computed tomography (CT) provides a non-invasive means of assessing StLNs, but its diagnostic accuracy for identifying metastases is unclear. In this retrospective cross-sectional study, we assessed the diagnostic power of various CT measurements. Fifty-seven dogs that underwent concurrent CT and cytological examination of the StLNs were enrolled retrospectively. The size, shape, X-ray attenuation and uniformity of the StLNs were assessed. The dogs were divided into metastasis-negative (n = 21) and metastasis-positive (n = 36) groups. Logistic regression analysis showed that the size (StLN-to-second sternebra ratio [ratio-size]) and precontrast attenuation were significantly different between groups. Combining these parameters achieved a specificity and positive predictive value of 100% (cut-off values: 1.0, 37.5 Hounsfield units, respectively). This suggests that the combination of ratio-size and precontrast attenuation is effective for differentiating metastasis to the StLNs on CT.

Combination Chlorambucil/Firocoxib or Chlorambucil/Prednisolone Treatment for Inflammatory Colorectal Polyps in Miniature Dachshunds

Inflammatory colorectal polyps (ICRP), which are more commonly recognized in miniature dachshunds, are thought to represent an immune-mediated disease. This retrospective case series describes six miniature dachshunds with refractory ICRP, who were treated with chlorambucil (CLB) combined with firocoxib or prednisolone. Improvement in clinical manifestations was seen in five of the six dogs by the end of the study period; four were treated with CLB/firocoxib and one with CLB/prednisolone. One dog had nonregenerative anemia after 23 mo of treatment with CLB, but whether there was a causative relationship was unclear. No severe adverse events were observed during treatment in the remaining five dogs. CLB in combination with firocoxib or prednisolone appears to be an effective alternative treatment for ICRP in dogs. Further studies are needed to confirm the effectiveness and long-term complications of CLB treatment for ICRP in dogs.

Measurements of body surface area and volume in laboratory rabbits (New Zealand White rabbits) using a computed tomography scanner

The body surface area (BSA) of an organism is one of the important parameters for evaluating physiological functions. In drug development, normalization by BSA is an appropriate method for extrapolating doses between species. The BSA of animals has generally been estimated by multiplying the k value by 2/3 of the power of the body weight (BW) (Meeh’s formula). In mathematics, if it is assumed that the density and body shape of the animals are essentially constant, the BSA is proportional to BW2/3. In this study, we measured the BSA and volume (V) of 72 laboratory rabbits (48 males and 24 females of New Zealand White rabbits [NZW]), using a computed tomography scanner. After BSA and V determination, the k value, density, and sphericity were calculated. We analyzed variations in the k value, density, and body shape of laboratory rabbits. The mean k value of the 72 NZW was 11.0. We advocate using Meeh’s formula, as follows, for estimating BSA of laboratory rabbits (NZW): 100 × BSA [m2] = 11.0 × BW [kg]2/3.