Optical Coherence Tomography Used for In Vivo Mapping of Nonmelanoma Skin Cancer

A major benefit a new imaging technology, called photodynamic therapy (PDT), for nonmelanoma skin cancers over traditional surgical excision is that it is noninvasive and therefore avoids surgery scars. This is a major advantage for the patient, because this type of skin cancer frequently occurs on the face, where disfiguring scars are highly undesirable.

However, because no tissue is removed for analysis in the PDT procedure, it can be difficult for clinicians to be sure that they have effectively treated the tumor, and this has limited its clinical use. A case study performed at University College Hospital London (UK) describing the successful use of Michelson Diagnostics' (Orpington, Kent, UK) VivoSight OCT scanner for in vivo mapping of nonmelanoma skin cancer was published in the March 2011 issue of the journal Photodiagnosis and Photodynamic Therapy.

The case study revealed that the use of a new VivoSight laser scanner developed by Michelson Diagnostics, Ltd., to image skin before, during, and after PDT treatment, could solve this problem. The case study was performed by Dr. Zaid Hamdoon and a team led by Dr. Colin Hopper at the unit of oral and maxillofacial surgery, University College Hospital London.

The VivoSight scanner uses the novel laser imaging technique OCT. This provides images of subsurface tissue similar to ultrasound, but at far higher resolution, enabling the clinician to see key facets of the skin epidermis and dermis in real time. Michelson Diagnostics has already obtained the CE marking and US Food and Drug Administration (FDA) clearance for clinical use of the scanner in Europe and the United States, and it is being evaluated at leading cancer clinics in Europe and the United States.

According to the authors of the study, "For each clinically visible margin, the pattern of the damage and the degree of tumor extension were clearly identified. Some areas exhibited almost perfect coregistration between the visible margin and OCT scan in term of evident histological damage….With the advent of new optical technologies such as OCT, we can now monitor lesions more precisely and accurately so obviating many of the previous shortcomings of PDT. To our knowledge, this case study reports the first application of OCT for in vivo imaging, mapping of nonmelanoma skin cancer. Additionally, OCT may help clinicians to monitor the outcome after the treatment, improving their understanding of the technique and offering an indication of the possible result to the patients….By other innovative approaches such as OCT-guided fine needle aspiration cytology of treated areas we can now confirm the absence of cancer or necessitate further treatment without the need to ablate normal tissues."

Prof. Colin Hopper, the lead investigator of the case study, added, "This case study is part of a larger program of ground-breaking research at our unit into using OCT imaging for clinical benefit of cancer patients. As well as improving PDT, mapping skin cancer lesions with OCT should improve delivery of other treatments such as Mohs surgery. We are looking to integrate OCT into our routine clinical pathway."

Michelson Diagnostics develops imaging products using a technology called multi-beam optical coherence tomography. The technology provides real time images of up to 2 mm into tissue with a resolution of better than 10 micrometers. The company's VivoSight OCT scanner has CE and FDA 510(k) clearance for use to aid clinical assessments in the field of dermatology including nonmelanoma skin cancer evaluation and guiding skin cancer surgery.

Related Links:
University College Hospital London
Michelson Diagnostics