The goal of this observational study is to find out if Raman Spectroscopy, a type of imaging, can be used to determine the size of skin cancer tumors. The main question it aims to answer is:

-Can Raman Spectroscopy help figure out how far a tumor spreads?

This study will take measurements using laser light from an experimental, handheld probe by lightly touching the skin.

Radiation therapy is an alternative to surgery for localized tumors with excellent tumor control and cosmetic outcome. Raman Spectroscopy has potential to be a useful non-invasive, non-destructive, real-time, in-vivo tool for differentiation of cancerous vs. non-cancerous tissues. With this knowledge and future studies, this will ultimately guide skin brachytherapy more accurately and avoid unnecessary radiation to cosmetically and functionally important tissues including eyelid, nose, lips or skin folds.

The purpose of this study is to determine the feasibility of Raman Spectroscopy to identify microscopic infiltration extent of skin cancer beyond grossly visible tumor, using artificial intelligence methods of supervised and un-supervised machine learning algorithms, including pattern recognition, convolutional neural networks, k-means clustering and principal component analysis.

Inclusion Criteria:

• Histologically confirmed skin cancer (either basal cell carcinoma or squamous cell carcinoma)
• Participants must plan to receive brachytherapy treatment for the skin cancer at the study site.
• Ability to provide consent to the study.

Exclusion Criteria:

• Patient belongs to a vulnerable population (Minors (under 18 years old), Adults unable to consent, prisoners).
• Lesions on the eyelid or in close proximity to the eye
• Pregnant women, or women of childbearing age who refuse pregnancy testing.
• Patient has pacemaker.

The population will include patients with confirmed skin cancer.