Non-invasive Fluorescent Imaging System for Imaging Mohs Tumor

The incidence of non-melanoma skin cancers, i.e. basal cell and squamous cell carcinoma (BCC
and SCC), in the US is over 5.4 million. Of these, BCC represents the majority, with an
incidence of over 4 million. Recent guidelines published on the treatment of BCC and SCC
establish Mohs micrographic surgery (MMS) as the treatment of choice for high-risk SCCs and
BCCs and for those in cosmetically sensitive locations.

MMS involves the step-wise removal and subsequent histological examination of thin layers of
cancer containing skin until only cancer-free tissue remains. At the initial layer, only
clinically involved skin is excised. The excised tumor is oriented using purposeful marks on
the tissue and color-coding. Using this orientation, a "Mohs map" is drawn to indicate where
malignancy is seen histologically. For each following layer, orientation is maintained, and
only margins with remaining malignant tissue are removed as indicated on the map. As the goal
is to spare as much normal tissue as possible, Mohs layers are only a few millimeters thin.
The average number of layers needed to remove an entire tumor per Mohs case is cited as 1.74.
However, outlier providers - that take a fewer or higher number of layers to clear a cancer-
do exist. While this could represent providers who see more complicated cases, and skin
tumors are often more extensive than initially clinically apparent, the need to balance
efficiency with the width of a layer likely also plays a role.

Fluorescence image guided surgery using Indocyanine green (ICG), an FDA approved
near-infrared (NIR) dye, has been used for effective visualization of intra-osseous tumoral
tissues in real-time, allowing surgeons to make intraoperative decisions for further
resection of otherwise clinically-uninvolved tissue. The use of intradermal ICG in a
cutaneous tumor during MMS could allow surgeons to directly visualize, and roughly map the
extent of a primary skin cancer preoperatively and plan the Mohs procedure (i.e. the initial
excision size and subsequent layer widths) accordingly. No current such mapping system exists
for use in cutaneous tumors.

Thus, while MMS represents an effective methodology to remove malignant tissue and spare as
much normal skin as possible, it is a lengthy process totaling several hours, and given the
need for histological processing at each stage, its duration primarily correlates with the
number of layers or stages needed. A pre-operative map of the extent of the tumor could allow
for: (1) a larger first layer - on the initial excision, only clinically evident tumor is
excised, but skin tumors are at times more extensive that clinically apparent; and the Mohs
surgeon to take thicker subsequent layers as needed. Effective and accurate pre-operative
tumor mapping with ICG therefore has the potential to reduce the total number of Mohs layers
taken for a patient. This is effect would improve patient safety and quality of care, and
reduce unnecessary financial burden associated with outliers. As a decreased number of layers
would directly shorten the total procedure length, preoperative mapping also has the
potential to help increase patient access to MMS.

Inclusion Criteria:

Subjects who are scheduled to undergo Mohs surgery for a basal cell carcinoma tumor, with a
minimum tumor size of 1.5 cm, will be selected for the study procedure. A total of 10
subjects are required to complete the study. We will need to consent 15 subjects to achieve
a total of 10 subjects to complete the study.

- Individuals 18 years or older

- All races and ethnicity

- Smokers and non-smokers

Exclusion Criteria: