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Nolan MW, Gieger TL. Update in Veterinary Radiation Oncology: Focus on Stereotactic Radiation Therapy. Vet Clin North Am Small Anim Pract 2024; 54:559-575. [PMID: 38160099 DOI: 10.1016/j.cvsm.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
Stereotactic radiotherapy (SRT) involves the precise delivery of highly conformal, dose-intense radiation to well-demarcated tumors. Special equipment and expertise are needed, and a unique biological mechanism distinguishes SRT from other forms of external beam radiotherapy. Families find the convenient schedules and minimal acute toxicity of SRT appealing. Common indications in veterinary oncology include nasal, brain, and bone tumors. Many other solid tumors can also be treated, including spinal, oral, lung, heart-base, liver, adrenal, and prostatic malignancies. Accessibility of SRT is improving, and new data are constantly emerging to define parameters for appropriate case selection, radiation dose prescription, and long-term follow-up.
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Affiliation(s)
- Michael W Nolan
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, USA.
| | - Tracy L Gieger
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC 27607, USA
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Scudder C, Church D. Feline Comorbidities: Hypersomatotropism-induced diabetes in cats. J Feline Med Surg 2024; 26:1098612X241226690. [PMID: 38323402 PMCID: PMC10911310 DOI: 10.1177/1098612x241226690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
PRACTICAL RELEVANCE Diabetes mellitus is the second-most common feline endocrinopathy, affecting an estimated 1/200 cats. While the underlying causes vary, around 15-25% of cats with diabetes mellitus develop the condition secondarily to progressive growth hormone (GH)-induced insulin resistance. This typically results in a form of diabetes that is challenging to manage, whereby the response to insulin is very variable or high doses are required to achieve even minimal diabetic control. CLINICAL CHALLENGES Although uncontrolled chronic excessive GH may result in phenotypic changes that raise suspicion for acromegaly, many cats with hypersomatotropism (HST) do not have these changes. In these situations, a clinician's index of suspicion may be increased by the presence of less dramatic changes such as marked polyphagia, stertor or uncontrolled diabetes mellitus. The current diagnostic test of choice is demonstration of a markedly increased serum insulin-like growth factor 1 (IGF1) concentration, but some affected cats will have only a marginal increase; additionally, chronic insulin administration in cats results in an increase in serum IGF1, making the diagnosis less clear cut and requiring additional confirmatory tests. EVIDENCE BASE Over the past two decades, HST has increasingly been recognised as an underlying cause of diabetes mellitus in cats. This review, which focuses on diagnosis and treatment, utilises data from observational studies, clinical trials and case series, as well as drawing on the experience of the authors in managing this condition.
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Affiliation(s)
- Christopher Scudder
- Department of Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hertfordshire, UK
| | - David Church
- Department of Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hertfordshire, UK
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Steele MME, Lawson JS, Scudder C, Watson AH, Ho NTZ, Yaffy D, Batchelor D, Fenn J. Transsphenoidal hypophysectomy for the treatment of hypersomatotropism secondary to a pituitary somatotroph adenoma in a dog. J Vet Intern Med 2024; 38:351-357. [PMID: 37916616 PMCID: PMC10800194 DOI: 10.1111/jvim.16929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/19/2023] [Indexed: 11/03/2023] Open
Abstract
Pituitary-dependent hypersomatotropism is rarely diagnosed in dogs and surgical treatment is not reported. A 6-year-10-month male neutered Patterdale Terrier presented with polyuria, polydipsia, progressive pharyngeal stertor, excessive hair growth and widened facial features and paws. Serum insulin-like growth factor-1 concentration via radioimmunoassay was consistent with hypersomatotropism (1783 ng/mL). A pituitary mass was identified on magnetic resonance and computed tomography imaging. Six weeks later, glucosuria, starved hyperglycemia and serum fructosamine above the reference range (467.6 μmol/L, RI 177-314) were documented, consistent with diabetes mellitus. Transsphenoidal hypophysectomy was performed under general anesthesia without complications. Pituitary histopathology identified an acidophil neoplasm, with positive immunostaining for growth hormone. Postoperatively, there was rapid resolution of clinical, biochemical and morphologic changes of hypersomatotropism with persistence of diabetes mellitus. This case demonstrates successful resolution of hypersomatotropism with ongoing diabetes mellitus in a dog after surgical treatment by transsphenoidal hypophysectomy.
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Affiliation(s)
| | - Jack S. Lawson
- Department of Clinical Science and ServicesRoyal Veterinary CollegeHatfieldUK
| | - Christopher Scudder
- Department of Clinical Science and ServicesRoyal Veterinary CollegeHatfieldUK
| | - Alice H. Watson
- Department of Clinical Science and ServicesRoyal Veterinary CollegeHatfieldUK
| | - Nicola T. Z. Ho
- Department of Clinical Science and ServicesRoyal Veterinary CollegeHatfieldUK
| | - Dylan Yaffy
- Department of Pathobiology and Population SciencesRoyal Veterinary CollegeHatfieldUK
| | - Daniel Batchelor
- Department of Small Animal Clinical SciencesUniversity of LiverpoolNestonUK
| | - Joe Fenn
- Department of Clinical Science and ServicesRoyal Veterinary CollegeHatfieldUK
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Černá P, Antonakakis M, Peralta J, Kofron K, Hawley J, Morris A, Lappin MR. Total thyroxine and thyroid-stimulating hormone responses of healthy cats to different doses of thyrotropin-releasing hormone. J Vet Diagn Invest 2024; 36:56-61. [PMID: 37968868 PMCID: PMC10734576 DOI: 10.1177/10406387231212816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023] Open
Abstract
Thyrotropin-releasing hormone (TRH) stimulation can be used as a test of thyroid function and pituitary thyrotropin (thyroid-stimulating hormone, TSH) reserve, but optimal stimulation testing protocols in cats are unreported. We randomly divided 6 healthy young adult cats into 3 groups of 2 and administered 3 different intravenous doses of TRH (0.01, 0.05, 0.1 mg/kg) at weekly intervals in our crossover study. Serum TSH and thyroxine (T4) concentrations were measured using chemiluminescent immunoassay before, and at 30 and 60 min after, TRH administration. All cats were monitored for 4 h post-TRH administration for side effects. All 3 TRH doses induced significant TSH (0.01 mg/kg, p = 0.001; 0.05 mg/kg, p = 0.002; 0.1 mg/kg, p = 0.006) and total T4 (0.01 mg/kg, p = 0.008; 0.05 mg/kg, p = 0.006; 0.1 mg/kg, p = 0.001) responses. Lower TRH doses (0.01 and 0.05 mg/kg) caused fewer side effects (1 of 6 cats) than did the highest dose (3 of 6 cats), and may be safer in cats than the previously reported higher dose (0.1 mg/kg) of TRH. Our results do not support the use of maropitant to prevent side effects of a TRH stimulation test in cats.
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Affiliation(s)
- Petra Černá
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Markos Antonakakis
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Jade Peralta
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Kristine Kofron
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Jennifer Hawley
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Arianne Morris
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Michael R. Lappin
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
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Niessen SJM. Hypersomatotropism and Other Causes of Insulin Resistance in Cats. Vet Clin North Am Small Anim Pract 2023; 53:691-710. [PMID: 36906467 DOI: 10.1016/j.cvsm.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
True insulin resistance should be differentiated from management-related difficulties (eg, short insulin duration, inappropriate insulin injection, inappropriate storage). Hypersomatotropism (HST) is the number one cause of insulin resistance in cats, with hypercortisolism (HC) occupying a more distant second place. Serum insulinlike growth factor-1 is adequate for screening for HST, and screening at the time of diagnosis, regardless of presence of insulin resistance, is advocated. Treatment of either disease centers on removal of the overactive endocrine gland (hypophysectomy, adrenalectomy) or inhibition of the pituitary or adrenal glands by using drugs such as trilostane (HC), pasireotide (HST, HC) or cabergoline (HST, HC).
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Affiliation(s)
- Stijn J M Niessen
- Royal Veterinary College London, UK; Veterinary Specialist Consultations and VIN Europe, Loosdrechtseweg 56, Hilversum 1215 JX, the Netherlands.
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Rohrer Bley C, Wolf F, Gonçalves Jorge P, Grilj V, Petridis I, Petit B, Böhlen TT, Moeckli R, Limoli C, Bourhis J, Meier V, Vozenin MC. Dose- and Volume-Limiting Late Toxicity of FLASH Radiotherapy in Cats with Squamous Cell Carcinoma of the Nasal Planum and in Mini Pigs. Clin Cancer Res 2022; 28:3814-3823. [PMID: 35421221 PMCID: PMC9433962 DOI: 10.1158/1078-0432.ccr-22-0262] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/02/2022] [Accepted: 04/12/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE The FLASH effect is characterized by normal tissue sparing without compromising tumor control. Although demonstrated in various preclinical models, safe translation of FLASH-radiotherapy stands to benefit from larger vertebrate animal models. Based on prior results, we designed a randomized phase III trial to investigate the FLASH effect in cat patients with spontaneous tumors. In parallel, the sparing capacity of FLASH-radiotherapy was studied on mini pigs by using large field irradiation. EXPERIMENTAL DESIGN Cats with T1-T2, N0 carcinomas of the nasal planum were randomly assigned to two arms of electron irradiation: arm 1 was the standard of care (SoC) and used 10 × 4.8 Gy (90% isodose); arm 2 used 1 × 30 Gy (90% isodose) FLASH. Mini pigs were irradiated using applicators of increasing size and a single surface dose of 31 Gy FLASH. RESULTS In cats, acute side effects were mild and similar in both arms. The trial was prematurely interrupted due to maxillary bone necrosis, which occurred 9 to 15 months after radiotherapy in 3 of 7 cats treated with FLASH-radiotherapy (43%), as compared with 0 of 9 cats treated with SoC. All cats were tumor-free at 1 year in both arms, with one cat progressing later in each arm. In pigs, no acute toxicity was recorded, but severe late skin necrosis occurred in a volume-dependent manner (7-9 months), which later resolved. CONCLUSIONS The reported outcomes point to the caveats of translating single-high-dose FLASH-radiotherapy and emphasizes the need for caution and further investigations. See related commentary by Maity and Koumenis, p. 3636.
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Affiliation(s)
- Carla Rohrer Bley
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Friederike Wolf
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Patrik Gonçalves Jorge
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Veljko Grilj
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ioannis Petridis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Benoit Petit
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Till T Böhlen
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Raphael Moeckli
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles Limoli
- Department of Radiation Oncology, School of Medicine, University of California at Irvine, Irvine, California
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Valeria Meier
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
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