Veterinary Medicine - August 2008 - (Page 432)

Practical Matters PEER-REVIEWED Importance of thoracic radiography in patients with cancer O ne might be tempted to say that a tumor that rarely spreads to the lungs does not require thoracic radiography, but I cannot think of any instance in a cancer patient’s work-up in which looking at the thorax is unnecessary. Oncologists frequently recommend thoracic radiography for staging cancer, especially since lung masses cannot be heard and tissues in the thorax cannot be palpated. Even if a tumor rarely metastasizes to the lungs, it does not mean it never does; it just means it is less likely to. Although rare, tumors such as hemangiopericytomas and mast cell tumors can metastasize and evidence of metastasis could be present when the patient presents for initial evaluation. This metastasis may severely alter therapy recommendations. Thoracic radiography may show other metastatic lesions in structures such as the ribs, vertebral bodies, heart base, or thoracic lymph nodes. Primary lung tumors (with or without metastases) may also be identiﬁed. It is possible for patients to have more than one kind of tumor simultaneously. In addition, a mass thought to be lying only external to the thoracic wall may be seen inside the thoracic cavity, indicating a more serious problem than the physical examination elucidated. Thoracic radiography may also reveal that a patient has a concurrent nonneoplastic disease. For example, lung abnormalities due to allergic, infectious, or inﬂammatory conditions may be visualized and require further diagnostic tests. Although clients may not report signs of heart disease, signs are often evident on physical examination, and, occasionally, radiographs show that the murmur you auscultated is related to a more serious problem than initially thought. In general, we use thoracic radiography to make sure a cancer patient is free of metastasis, but we also use it to make sure the patient is healthy enough to undergo treatment. The most debated aspect of thoracic imaging is whether to obtain two views or three views (a right lateral, a left lateral, and a dorsoventral or ventrodorsal). The primary reason to take three views of the chest is to detect lung nodules in areas not seen with two views, primarily the down lung tissue that is less aerated. I rarely take three radiographic views of a chest, but I do ask for two views even when a patient is scheduled for computed tomography (CT) because it would be unfortunate (e.g. increased time, cost, anesthesia risk) to diagnose Janean Fidel, DVM, MS, DACVR numerous large masses in the lungs with CT. (radiation oncology), If I am concerned about small nodules, I am likely to DACVIM (oncology) Department of recommend thoracic CT since 3-mm nodules can be Veterinary Clinical accurately detected with this imaging modality. Sciences College of Veterinary Thoracic radiography can be an inexpensive initial Medicine method for screening for many different problems in Washington State University patients with cancer. Never underestimate the value of Pullman, WA 99164 thoracic radiography. 432 August 2008 VETERINARY MEDICINE http://www.reconcile.com http://www.reconcile.com

Table of Contents Feed for the Digital Edition of Veterinary Medicine - August 2008

Veterinary Medicine - August 2008 Contents Editors' Note Leading Off ClinQuiz Idea Exchange Practical Matters Diagnosing and Treating Canine Copper-Associated Hepatopathies Canine and Feline Demodicosis CE Form Advertiser Index Product Preview Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - August 2008

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