Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Dec;34(6):622-628.
doi: 10.1177/19714009211017777. Epub 2021 Jun 2.

Assessing the accuracy of computed tomography in detecting bony invasion and thickness of squamous cell carcinoma of the scalp

Conor T Boylan  1 , Michaela S Gaston  1 , Puja Merwaha  1 , Kurdow Nader  2 , Sukhbir Rayatt  2
Affiliations

Assessing the accuracy of computed tomography in detecting bony invasion and thickness of squamous cell carcinoma of the scalp

Conor T Boylan et al. Neuroradiol J. 2021 Dec.

Abstract

Objectives: The aim of this study was to ascertain the accuracy of computed tomography (CT) in assessing the presence of bony involvement and thickness of squamous cell carcinoma (SCC) of the scalp.

Methods: A single-centre retrospective chart review was carried out. Inclusion criteria were scalp SCC, CT between January 2008 and 2018, and the availability of a reference test. Reference tests were either histology, surgical notes or clinical notes. Tabular assessment of accuracy was performed and Student's t-test, Mann-Whitney U test and Fisher exact test were used in univariable analysis. Accuracy of thickness measurement was calculated using the limits of agreement method, and linear regression was used to examine trend.

Results: Thirty-nine patients were included. Most patients were male (74.4%), white (97.4%), not immunosuppressed (66.6%) and had poorly differentiated tumours (33.3%). The most common tumour sites were the vertex (28.2%) and temporal region (23.1%). Sensitivity of CT in detecting presence or absence of bony invasion of scalp SCC was 76.9% (95% CI 46.2-94.9%) and specificity was 96.2% (95% CI 80.4-99.9%). Overall accuracy was 89.7% (95% CI 75.8-97.1%), positive predictive value was 90.1% (95% CI 58.7-99.8%) and negative predictive value was 89.3% (95% CI 71.8-97.7%). No significant differences were found comparing patients with an accurate or inaccurate CT scan. Thickness on CT was found to be consistent with histological thickness at the 95% confidence level.

Conclusions: CT is accurate at assessing the presence of bony involvement and thickness of scalp SCC. This study was limited somewhat by small sample size.

Keywords: Computed tomography; bony invasion; depth assessment; scalp tumours; squamous cell carcinoma.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Contrast-enhanced CT head showing a large soft tissue defect over the right superior occipitoparietal area with marked thinning of the outer table of the underlying calvarium.
Figure 2.
Figure 2.
Non-enhanced CT head showing a localised skin defect in the left high frontal region with deep underlying bone erosion involving the outer and inner tables of the underlying calvarium. The permeative bone changes are multifocal and extend over approximately 3 cm diameter. No extension beyond the inner table is seen, with no evidence of involvement of the dura or brain parenchyma.
Figure 3.
Figure 3.
Diagram showing flow of participants through the study.
Figure 4.
Figure 4.
Scatter graph to show thickness on CT vs thickness on histology. Black line is line of no difference.
Figure 5.
Figure 5.
Bland–Altman plot showing difference between histological and CT thickness vs mean thickness across the two methods. Dashed horizontal lines are upper (upper line) and lower (lower line) limits of agreement at 95% confidence. Solid horizontal line is the mean difference.
See this image and copyright information in PMC

References

    1. Prodinger C, Koller J, Laimer M. Scalp tumors. J Dtsch Dermatol Ges 2018; 16(6): 730–753. - PubMed
    1. Motherway J, Verschueren P, Van der Perre G, et al. The mechanical properties of cranial bone: the effect of loading rate and cranial sampling position. J Biomech 2009; 42(13): 2129–2135. - PubMed
    1. Boylan C, Gaston M, Merwaha P. A proposed system for redefining of the zones of the scalp. Int J Trichol 2020; 12(3): 140. - PMC - PubMed
    1. Brash D, Rudolph J, Simon J, et al. A role for sunlight in skin cancer: UV-induced p53 mutations in squamous cell carcinoma. Pro Natl Acad Sci U S A 1991; 88(22): 10124–10128. - PMC - PubMed
    1. Venables Z, Nijsten T, Wong K, et al. Epidemiology of basal and cutaneous squamous cell carcinoma in the U.K. 2013–15: a cohort study. Br J Dermatol 2019; 181(3): 474–482. - PMC - PubMed