Assessment of Tumor Thickness in Melanocytic Skin Lesions: Comparison of Optical Coherence Tomography, 20-MHz Ultrasound and Histopathology

Abstract

Background: Accurate assessment of vertical tumor size is important for surgical treatment planning of melanocytic skin lesions. High-frequency ultrasound (HFUS) is frequently used for this purpose, but overestimation of tumor thickness is known as a problem especially in thin melanocytic lesions. Optical coherence tomography (OCT) as a new imaging technique might be a promising alternative. Objective: To evaluate the ability of OCT to accurately determine the vertical tumor thickness of melanocytic skin lesions and to compare it with HFUS and histopathology in order to improve surgical planning. Methods: In this single-center study, 26 melanocytic lesions were imaged by OCT and HFUS. Vertical lesion dimensions of both methods were compared with histopathological measurements. Results: Bland-Altman plots for OCT and histopathology as well as for HFUS and histopathology revealed better agreement for OCT and histopathology concerning tumor thickness measurements. Tumor thickness values for the melanocytic lesions measured by OCT presented a median tumor thickness of 0.31 mm (range 0.10–0.77) compared to a median tumor thickness of 0.25 mm (range 0.06–1.5) measured by histopathology. The median tumor thickness of HFUS was 0.44 mm (range 0.23–1.1). A Spearman correlation procedure including the correlation coefficient (r) showed a stronger relationship between OCT and histopathology (r = 0.734) compared to HFUS and histopathology (r = 0.390). Conclusions: On the basis of this smaller study cohort, OCT seems to be more exact than HFUS as far as thickness determination of thin melanocytic skin lesions is concerned.

High-Definition Optical Coherence Tomography for the in vivo Detection of Demodex Mites

“…in the diagnostics of nonmelanoma skin cancer, for the measurement of tumor thickness of melanocytic lesions, for the evaluation of epidermal changes after different topical treatments and in the assessment of psoriatic nail disorders [13,15,16,17,18,19]. …”

Modern non-invasive diagnostic techniques in the detection of early cutaneous melanoma

“…OCT was used for monitoring non-surgical treatment (imiquimod) of lentigo maligna. [43][44][45] The results of these studies showed a good correlation between OCT and pathology. In OCT melanoma is characterized by marked architectural disarray and presence of vertical, icicle-shaped structures.…”

“…Both HFU and OCT tend toward tumor depth overestimation compared to histopathological ex vivo tumor measurement. 45 …”

The skin microbiopsy

“…The OCT has an optical resolution of [3][4][5][6][7][8][9][10][11][12][13][14][15] mm and can image up to 1 mm in depth (Kardynal and Olszewska, 2014). Hinz et al have shown that OCT has a stronger correlation with histopathology than HFU (Spearmen correlation, r = 0.734) (Hinz et al, 2011). They compared the tumor thickness of 26 melanocytic lesions measured from histopathology to OCT and HFU.…”

“…The median tumor thickness on histopathology was 0.25 mm while OCT and HFU were 0.31 mm and 0.44 mm, respectively. The concluded that OCT provides more accurate tumour depth than HFU that is frequently used for surgical planning for cutaneous melanocytic lesions (Hinz et al, 2011). OCT may have a lower resolution compared to RCM but it can provide realtime imaging to detect gross alteration in skin structure that can be easily correlated to conventional histopathology (Figure 1.5).…”