Mohs micrographic surgery has long been the standard for treating non-melanoma skin cancer (NMSC), particularly on sensitive areas like the face, neck, and hands. This surgical approach offers high cure rates by systematically removing and analyzing thin layers of cancerous tissue until clear margins are confirmed. Recent technological advancements have introduced a non-surgical alternative for treating basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). This new option allows physicians to achieve comparable results without the need for a scalpel, stitches, or surgical wound care.
Image-Guided Superficial Radiotherapy
The modern alternative is Image-Guided Superficial Radiotherapy (IG-SRT), an evolution of traditional superficial radiation therapy. This treatment uses low-energy X-rays, similar to those used in dental X-rays, to destroy cancer cells on the skin’s surface and just beneath it. The radiation targets the cancer’s cellular DNA, preventing the cells from dividing and causing them to die off.
The “Image-Guided” component transforms this treatment into a highly precise tool. High-resolution dermal ultrasound (HRDUS) is integrated to visualize the tumor in real-time before each session. This imaging allows the medical team to precisely measure the cancer’s depth, width, and shape for accurate treatment planning. By using this real-time imaging, the radiation dose is precisely delivered to the cancerous tissue while minimizing exposure to the surrounding healthy skin. This ensures the treatment is highly targeted, offering margin control that rivals the microscopic assessment of Mohs surgery for appropriate tumors.
How the Treatment Protocol Works
The IG-SRT treatment protocol is fundamentally different from a single-day surgical procedure, focusing on a non-invasive, fractional approach over several weeks. Patients receive a series of short, painless sessions, often ranging from 18 to 30 total treatments. These sessions are scheduled three to five times per week for approximately four to seven weeks, with each session lasting about 10 to 15 minutes.
This extended, fractionated schedule allows the cumulative radiation dose to kill cancer cells while giving the surrounding healthy tissue time to repair itself between treatments. The treatment is performed in an outpatient clinic setting, and patients experience no downtime, enabling them to return to normal daily activities immediately. IG-SRT is an option for patients with contraindications to surgery, such as those with pacemakers or on blood-thinning medications. It is also suitable for elderly individuals or those with tumors located in cosmetically or functionally complex areas, like the nose, ear, or eyelid.
Comparing Radiotherapy and Mohs Surgery
When comparing IG-SRT and Mohs surgery, modern data suggests that cure rates for early-stage BCC and SCC are statistically comparable. Mohs surgery boasts a cure rate between 96% to 99% for primary non-melanoma skin cancers, while IG-SRT protocols consistently report cure rates exceeding 99% for appropriate lesions. The difference lies in the method of clearance: Mohs provides microscopic confirmation on the day of surgery, while IG-SRT relies on precise imaging and fractionated dose delivery.
The recovery and downtime associated with the two modalities present a significant contrast. Mohs surgery involves a surgical incision and subsequent reconstruction, requiring wound care for several weeks and potential limitations on activity. Conversely, IG-SRT is completely non-invasive, meaning there is no cutting, stitches, or bleeding, and virtually no downtime. Patients only experience mild, temporary redness at the treatment site.
For lesions in aesthetically sensitive locations, cosmetic results often favor the non-surgical approach. Because IG-SRT uses external radiation to eliminate cancer cells, it preserves the underlying tissue structure, resulting in minimal to no scarring and avoiding surgical reconstruction. While Mohs surgery is designed to be tissue-sparing, it still creates a surgical defect that requires repair. This repair can sometimes lead to noticeable scarring or changes in the skin’s texture, especially when the initial defect is large or complex.