In this installment of Topical Conversations, Todd Schlesinger, MD, discusses an article published in the Journal of the American Academy of Dermatology by Wolswijk et al, titled “Optical coherence tomography for diagnosing recurrent or residual basal cell carcinoma after topical treatment: A diagnostic cohort study.” This study evaluated the use of optical coherence tomography (OCT) to diagnose recurrent or residual basal cell carcinoma (BCC) after topical treatment. 

Study background 

The small diagnostic cohort study involved 100 patients and aimed to determine if OCT could improve the accuracy of detecting superficial recurrent BCC after treatment with topical therapy (specifically imiquimod, 5-fluorouracil, and photodynamic therapy) compared to clinical and dermoscopic evaluation. 

Study outcomes on sensitivity and specificity 

The results showed that OCT improved the sensitivity and specificity of diagnosing recurrent superficial basal cell carcinoma after topical treatment. 

Patients were evaluated on whether there was a low or high suspicion of recurrence; patients with a high suspicion of recurrence underwent a punch biopsy, while patients with a low suspicion of recurrence underwent a control biopsy. 

The sensitivity for detection of recurrent or residual BCC was 60% with clinical and dermoscopic evaluation compared to 100% with OCT, suggesting that combining dermoscopy and clinical exam with OCT may significantly improve sensitivity. 

The specificity was over 95% for both methods. 

Limitations to the use of OCT in BCC diagnosis 

Dr Schlesinger notes that there are some limitations to the use of OCT in detecting recurrent BCC. Since OCT has a steep learning curve, the experience of the person interpreting the OCT images is crucial. 

He also notes that access to OCT may be limited due to its cost. 

The prospective role of OCT in BCC care 

The study suggests that incorporating OCT into practice can enhance diagnostic accuracy and potentially reduce the need for biopsies in recurrent BCC after topical therapy. Overall, the article highlights the potential benefits of using OCT for follow-up and detecting recurrence in patients with basal cell carcinoma. 

Key points 

• A diagnostic cohort study aimed to determine if OCT, in conjunction with clinical exam and dermoscopy, can improve detection of superficial recurrent BCC after topical therapy 
• Use of OCT improved sensitivity and specificity of diagnosing recurrent superficial BCC 
• Limitations include the experience level of the person interpreting the OCT images and cost-related access challenges 
• Incorporating OCT into practice may enhance diagnostic accuracy and potentially reduce need for biopsies in recurrent OCT after topical therapy