Optical coherence tomography for diagnosing recurrent or residual basal cell carcinoma after topical treatment: A diagnostic cohort study.

BACKGROUND: Recurrent/residual basal cell carcinoma (BCC) after topical treatment may not be visible during clinical and dermatoscopic examination (CDE). Optical coherence tomography (OCT) may detect these subclinical recurrences or residues. OBJECTIVE: To compare the diagnostic accuracy of CDE with that of CDE combined with OCT (CDE-OCT) for detecting recurrent/residual BCC after topical treatment of superficial BCC. METHODS: In this diagnostic cohort study, the suspicion level for recurrence or residue was recorded on a 5-point confidence scale. All patients with high suspicion of recurrence or residue based on CDE and/or CDE-OCT were referred for punch biopsy. Patients with a low suspicion on CDE and CDE-OCT were asked to (voluntarily) undergo a control biopsy. Histopathologic results of the biopsy were used for verification of CDE and CDE-OCT diagnoses (gold standard). RESULTS: This study included 100 patients. A histopathologic recurrent/residual BCC was found in 20 patients. For recurrence or residue detection, sensitivity was 100% (20 of 20) for CDE-OCT and 60% (12 of 20) for CDE (P = .005) and specificity was 95% for CDE-OCT and 96.3% for CDE (P = .317). The area under the curve for CDE-OCT (0.98) was significantly higher than that for CDE (0.77) (P = .001). LIMITATIONS: Results are based on 2 OCT assessors. CONCLUSION: Compared with CDE alone, CDE-OCT results in a significantly higher ability to detect recurrent/residual BCCs after topical treatment.

Optical coherence tomography versus punch biopsy for diagnosis of basal cell carcinoma: a multicentre, randomised, non-inferiority trial.

BACKGROUND: Punch biopsy is the gold standard for diagnosis and subtyping of basal cell carcinoma. The aim of this study was to assess whether use of optical coherence tomography (OCT), a non-invasive imaging tool, might avoid the need for biopsy. METHODS: In a multicentre, randomised, non-inferiority trial, patients (aged ≥18 years) with an indication for biopsy of a suspected basal cell carcinoma outside the H-zone (high-risk zone) of the face were randomly assigned (1:1) to receive either OCT or punch biopsy (regular care) via a web-based randomisation system. Patients were enrolled from three participating centres in the Netherlands: Maastricht University Medical Centre+, Catharina Hospital Eindhoven, and Zuyderland Medical Centre Heerlen. Stratification factors for randomisation were participating centre and the grade of clinical basal cell carcinoma suspicion (high vs low). The primary endpoint was the proportion of patients free from a recurrent or residual lesion (malignant or premalignant) 12 months after treatment. Modified intention-to-treat and per-protocol analyses were conducted, with a predefined non-inferiority margin of -10%. This trial is registered with ClinicalTrials.gov number, NCT03848078, and is complete. FINDINGS: Between Feb 25, 2019, and Sept 2, 2020, 598 patients were enrolled and randomly assigned to either the regular care group (n=299) or the OCT group (n=299). Data on the primary endpoint were available in 553 patients (n=268 in the regular care group, n=285 in the OCT group). After median follow-up of 12·7 months (IQR 11·2-14·1) in the OCT group and 12·6 months (10·8-14·3) in the regular care group, 253 (94%) of 268 patients in the OCT group and 266 (93%) of 285 patients in the regular care group were free from recurrent or residual lesions (malignant or pre-malignant) 12 months after treatment. According to our modified intention-to-treat analysis, the absolute difference (OCT vs regular care) was 1·07% (95% CI -2·93 to 5·06; one-sided p=0·30), with the lower limit of the 95% CI not exceeding the predefined non-inferiority margin of -10%. Per-protocol analyses led to proportions free from a residual or recurrent lesion (premalignant or malignant) of 95% (250 of 263) in the OCT group and 94% (262 of 278) in the regular care group, and an absolute difference of 0·81% (95% CI -2·98 to 4·60; one-sided p=0·34). INTERPRETATION: OCT-guided diagnosis and treatment of basal cell carcinoma is non-inferior to regular care punch biopsy. Implementation of OCT for diagnosis of basal cell carcinoma could reduce the number of consultations and invasive procedures. FUNDING: The Netherlands Organization for Health Research and Development and Maurits en Anna de Kock Stichting.

Diagnostic Value of Optical Coherence Tomography Image Features for Diagnosis of Basal Cell Carcinoma.

Optical coherence tomography (OCT) is a non-invasive diagnostic method. Numerous morphological OCT features have been described for diagnosis of basal cell carcinoma (BCC). The aim of this study is to evaluate the diagnostic value of established OCT features and to explore whether the use of a small set of OCT features enables accurate discrimination between BCC and non-BCC lesions and between BCC subtypes. For each lesion, the presence or absence of specific OCT features was recorded. Histopathology was used as a gold standard. Diagnostic parameters were calculated for each OCT feature, and multivariate logistic regression analyses were performed to evaluate the loss in discriminative ability when using a small subset of OCT features instead of all features that are characteristic for BCC according to the literature. The results show that the use of a limited number of OCT features allows for good discrimination of superficial BCC from non-superficial BCC and non-BCC lesions. The prevalence of BCC was 75.3% (225/299) and the proposed diagnostic algorithm enabled detection of 97.8% of BCC lesions (220/225). Subtyping without the need for biopsy was possible in 132 of 299 patients (44%), with a predictive value for presence of superficial BCC of 84.3% vs 98.8% for presence of non-superficial BCC.

Topical Application of Glycerol Increases Penetration Depth of Optical Coherence Tomography in Diagnosis of Basal Cell Carcinoma.

Optical coherence tomography is a non-invasive imaging technique that enables high-resolution in vivo imaging of skin. Although optical coherence tomography is promising for diagnosing basal cell carcinoma, its limited penetration depth may impede basal cell carcinoma subtyping. This study evaluated whether topical application of glycerol can increase penetration depth and improve the image quality and visibility of characteristic features of basal cell carcinoma. A total of 61 patients with a total of 72 basal cell carcinomas were included. Optical coherence tomography scans were obtained before and after application of an 85% glyce-rol solution. The mean penetration depth of each optical coherence tomography scan was acquired by automatically tracing both skin surface and the point of signal loss using a custom-made MATLAB program. Mean ± standard deviation penetration depth increased from 883 ± 108 to 904 ± 88 µm before and after glycerol application, respectively (p = 0.005). Topical application of glycerol leads to a significant 2.4% increase in penetration depth. However, no significant differences in image quality and visibility of basal cell carcinoma features were found.

'Pitfalls for differentiating basal cell carcinoma from non-basal cell carcinoma on optical coherence tomography: A clinical series'.

Optical coherence tomography (OCT), a non-invasive diagnostic modality, may replace biopsy for diagnosing basal cell carcinoma (BCC) if a high-confidence BCC diagnosis can be established. In other cases, biopsy remains necessary to establish a histopathological diagnosis and treatment regimen. It is, therefore, essential that OCT assessors have a high specificity for differentiating BCC from non-BCC lesions. To establish high-confidence BCC diagnoses, specific morphological BCC characteristics on OCT are used. This study aimed to review several cases of non-BCC lesions that were misclassified as BCC by experienced OCT assessors, thereby providing insight into the causes of these misclassifications and how they may be prevented. The study population consisted of patients who had a histopathologically-verified non-BCC lesion. Patients from Maastricht University Medical Center+ from February 2021 to April 2021 were included in the study. Two independent OCT assessors assessed OCT scans. One OCT assessor recorded the presence or absence of validated morphological BCC characteristics. A false-positive OCT test result was defined as certainty of BCC presence in a non-BCC lesion. The frequency of misclassifications and the presence or absence of morphological BCC features are discussed. A total of 124 patients with non-BCC lesions were included. Six patients were misclassified by both OCT assessors and are discussed in more detail. Histopathological diagnoses were squamous cell carcinoma (n = 2/21), actinic keratosis (n = 2/29), squamous cell carcinoma in situ/Bowen's disease (n = 1/16), or interphase dermatitis (n = 1/4). In all misclassified cases, multiple, apparent morphological BCC characteristics on OCT were present. Most non-BCC lesions are recognized as such by OCT assessors. However, there remains a small risk that a high-confidence BCC diagnosis is established in non-BCC lesions wherein features mimicking validated BCC characteristics are present. Misclassification may be prevented by careful delineation of epidermal layers and good differentiation between dermal ovoid structures typical of BCC versus squamous cell carcinoma.