Continuing medical education
The role of imaging in the management of patients with nonmelanoma skin cancer: Diagnostic modalities and applications

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While uncomplicated cases of nonmelanoma skin cancer can be treated with surgery, destruction, or topical therapy alone, advanced or neglected cases require more complex management decisions. Dermatologists and dermatologic surgeons should be familiar with the imaging techniques relevant to cutaneous oncology and their value in different clinical scenarios. Herein we review imaging modalities used in management of nonmelanoma skin cancer.

Introduction

As the incidence of skin cancer continues to rise, dermatologists and dermatologic surgeons in particular will encounter more aggressive tumors that may require imaging to optimize patient work-up and management. However, radiologic imaging of skin cancer is not a familiar topic to most dermatologists. There are but a few sources of information found in radiology texts1 and the dermatologic literature,2, 3 and it remains a knowledge gap in dermatology. In addition to streamlining patient care, an understanding of different imaging modalities will facilitate the use of cost effective imaging resources.4, 5 The objective of this article is to provide a current overview of imaging modalities pertinent to nonmelanoma skin cancer (NMSC) and to discuss clinical scenarios where imaging is indicated. For reasons of brevity and relevance to this audience, the discussion will exclude melanoma.

Section snippets

Anatomic planes of imaging

Cross-sectional imaging requires standard nomenclature to refer to the visualized plane. A correct understanding of the terminology used by radiologists is essential in the interpretation of imaging reports and communication. The commonly used anatomic planes in imaging studies (ie, axial or transverse, sagittal, and coronal) are shown in Fig 1.

Computed tomography basics

Key points

  1. Computed tomography is typically the initial imaging study in the preoperative evaluation of head and neck tumors

  2. Computed tomography scans offer superior spatial resolution compared to magnetic resonance imaging scans and excellent visualization of bony structures and lymph nodes

  3. Computed tomography scans can be quickly performed and are widely available

  4. Computed tomography scans involve exposure to ionizing radiation

  5. Computed tomography scans should be ordered with contrast for tumor imaging

Positron emission tomography–computed tomography basics

Key points

  1. Positron emission tomography–computed tomography is an excellent technique for the detection of hypermetabolic tumors, such as squamous cell and Merkel cell carcinomas, in lymph nodes and distant organs

  2. Positron emission tomography–computed tomography provides both structural and functional data

  3. Positron emission tomography–computed tomography is frequently used to evaluate the presence of occult metastases and monitor head and neck tumors postoperatively

Positron emission tomography–computed

Magnetic resonance imaging: The basics

Key points

  1. Magnetic resonance imaging scans have superior soft tissue contrast compared to computed tomography scans

  2. Magnetic resonance imaging scans allow for the evaluation of perineural invasion

  3. These scans do not involve ionizing radiation

  4. Cost, longer imaging time, and sensitivity to motion and magnetic interference can be drawbacks

  5. Magnetic resonance imaging scans should be ordered with contrast for tumor imaging

MRI scans, in contrast to CT scans, use no ionizing radiation. The first requirement is a

Basics of ultrasonography

Key points

  1. Ultrasonography is a noninvasive modality

  2. Ultrasonography can assess regional lymph node characteristics

  3. Ultrasonography is operator-dependent

  4. The evaluation of cutaneous tumors with ultrasonography requires specialized equipment

Ultrasonography (US) has been an essential tool in medical diagnosis since its emergence approximately 60 years ago. It can be used to image the primary tumor or assess lymph nodes.39, 40, 41, 42, 43, 44 High-frequency sound waves generated by the piezoelectric crystals in

References (51)

  • E. Hawryluk et al.

    Positron emission tomography imaging in Merkel cell carcinoma: a study of 270 scans in 97 patients at the Dana Farber/Brigham and Women's Cancer Center

    J Am Acad Dermatol

    (2013)
  • B.D. Lemos et al.

    Pathologic nodal evaluation improves prognostic accuracy in Merkel cell carcinoma: analysis of 5823 cases as the basis for the first consensus staging system

    J Am Acad Dermatol

    (2010)
  • J.F. Griffith et al.

    Neck ultrasound in staging squamous oesophageal carcinoma—a high yield technique

    Clin Radiol

    (2000)
  • R.B. de Bondt et al.

    Detection of lymph node metastases in head and neck cancer: a meta-analysis comparing US, USgFNAC, CT and MR imaging

    Eur J Radiol

    (2007)
  • A. Mancuso et al.
    (2011)
  • K. Shah et al.

    Imaging of head and neck skin cancer

  • A.B. Bautista et al.

    Do clinicians use the American Academy of Radiology Appropriateness criteria in the management of their patients?

    AJR Am J Roentgenol

    (2009)
  • G.N. Hounsfield

    Computerized transverse axial scanning (tomography): part 1. Description of system. 1973

    Br J Radiol

    (1995)
  • G.N. Hounsfield

    Computed medical imaging. Nobel lecture, December 8, 1979

    J Comput Assist Tomogr

    (1980)
  • M. Mahesh

    Search for isotropic resolution in CT from conventional through multiple-row detector

    RadioGraphics

    (2002)
  • P. Som et al.

    Imaging based nodal classification for evaluation of head and neck metastatic adenopathy

    AJR Am J Roentgenol

    (2000)
  • R. Smith-Bindman et al.

    Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer

    Arch Intern Med

    (2009)
  • D.J. Brenner et al.

    Computed tomography- an increasing source of radiation exposure

    N Eng J Med

    (2007)
  • A. Sodickson et al.

    Recurrent CT, cumulative radiation exposure and associated radiation-induced cancer risks from CT of adults

    Radiology

    (2009)
  • W. Friedberg et al.

    Radiation exposure during air travel: guidance provided by the FAA for air carrier crews

    Health Phys

    (2000)
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    Funding sources: None.

    Conflicts of interest: None declared.

    Date of release: April 2017

    Expiration date: April 2020

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