Why Melanoma Cannot Be Treated With SRT, and What Treatments Actually Work

Superficial radiation therapy, commonly called SRT, has become an increasingly popular nonsurgical option for certain skin cancers. It is effective, comfortable, and leaves minimal scarring, which makes it an attractive choice for many patients. But there is one important limitation that every patient should understand: SRT is not a treatment for melanoma. If you or a loved one has been diagnosed with melanoma, it is critical to know why SRT is not appropriate and what proven options are available.

What Is SRT and What Is It Used For

Superficial radiation therapy delivers low-energy X-rays that penetrate only the top layers of the skin. It is FDA-cleared for the treatment of nonmelanoma skin cancers, specifically basal cell carcinoma and squamous cell carcinoma, in select patients who are not good surgical candidates or who wish to avoid surgery for cosmetic or medical reasons. SRT works because basal and squamous cell carcinomas tend to stay confined to the upper layers of the skin and respond well to superficial doses of radiation.

Why SRT Does Not Work for Melanoma

Melanoma is a fundamentally different disease. It originates in melanocytes, the pigment-producing cells in the skin, and behaves more aggressively than basal or squamous cell carcinoma. Three key factors make SRT inappropriate for melanoma.

First, melanoma is notoriously radioresistant. Melanoma cells have biological repair mechanisms that allow them to survive doses of radiation that would destroy other skin cancers. Standard low-energy radiation simply does not reliably kill melanoma cells.

Second, melanoma can spread early and silently. Even small, thin melanomas can send microscopic cells into the lymphatic system or bloodstream long before the lesion looks alarming. SRT only treats the visible surface area, so it cannot address spread that has already occurred beneath the skin or beyond it.

Third, accurate staging requires tissue. The depth of a melanoma, measured in millimeters under a microscope, determines prognosis and treatment. Destroying the lesion with radiation eliminates the ability to perform that critical pathology, leaving patients and physicians without the information they need to make life-saving decisions.

For these reasons, every major dermatology and oncology guideline, including those from the National Comprehensive Cancer Network and the American Academy of Dermatology, makes clear that SRT is not a primary treatment for melanoma. If a provider offers SRT for a confirmed melanoma, seek a second opinion immediately.

Proven Treatments for Melanoma

Melanoma treatment depends on the stage of the disease, the location of the tumor, and the patient's overall health. The good news is that highly effective options exist, and survival rates have improved dramatically over the past decade thanks to advances in surgery, immunotherapy, and targeted therapy.

Mohs Micrographic Surgery

In certain cases, particularly for melanoma in situ or lentigo maligna on the face, Mohs surgery is often used. This technique removes the cancer in stages while examining each layer under the microscope, allowing for the highest cure rate while sparing as much healthy tissue as possible. Mohs is performed by specially trained dermatologic surgeons.

Wide Local Excision

Surgical removal is the cornerstone of melanoma treatment for nearly every patient with localized disease. A wide local excision removes the melanoma along with a margin of normal-appearing skin to capture any microscopic spread. The size of the margin is dictated by the depth of the tumor and follows established guidelines. For most early-stage melanomas, this single procedure can be curative.

Sentinel Lymph Node Biopsy

For melanomas above a certain depth, a sentinel lymph node biopsy is often recommended at the time of wide excision. This minimally invasive procedure identifies and tests the first lymph node that drains the tumor site. The result helps determine staging and guides decisions about further treatment.

Lymph Node Dissection

If cancer is found in the lymph nodes, additional surgery or close monitoring may be recommended. Modern guidelines have moved away from routine complete lymph node dissection in favor of careful surveillance and systemic therapy when appropriate.

Immunotherapy

Immunotherapy has transformed melanoma care. Checkpoint inhibitor drugs unlock the immune system's ability to recognize and destroy melanoma cells. These medications are used for advanced or metastatic melanoma, and increasingly for high-risk earlier-stage disease as adjuvant therapy after surgery. Many patients who once faced grim prognoses are now achieving long-term remission.

Targeted Therapy

Roughly half of melanomas carry a mutation in the BRAF gene. For these patients, oral targeted therapies, can shrink tumors quickly and significantly. Genetic testing of the tumor determines whether targeted therapy is an option.

Radiation Therapy When Appropriate

While SRT is not used for melanoma, conventional external beam radiation therapy does play a role in specific situations. It is sometimes used after lymph node surgery to reduce the risk of recurrence, to treat melanoma that has spread to the brain or bones, or to relieve symptoms in advanced disease. This is high-energy radiation delivered by a radiation oncologist, not the superficial therapy delivered in some dermatology offices.

Chemotherapy

Traditional chemotherapy is used much less often than in the past. With the success of immunotherapy and targeted therapy, drugs like dacarbazine are reserved for select cases where newer therapies are not options.

Clinical Trials

Melanoma research is one of the most active areas in oncology. Clinical trials offer access to novel combinations, personalized cancer vaccines, tumor-infiltrating lymphocyte therapy, and other emerging treatments. Patients with advanced melanoma should always ask whether a trial is appropriate.

The Bottom Line

If you have been diagnosed with melanoma, the right path forward is a thorough evaluation by a board-certified dermatologist, often in coordination with a surgical or medical oncologist. Surgery remains the foundation of treatment for localized disease, and remarkable advances in immunotherapy and targeted therapy have made even advanced melanoma far more treatable than it was even ten years ago. SRT has its place in dermatology, but melanoma is not it.

If you have a suspicious mole, a changing lesion, or a recent melanoma diagnosis and want to discuss your options, contact our office to schedule an evaluation. The earlier melanoma is found and treated with the right therapy, the better the outcome. Call us at (520) 382 - 3330 or click book now to make an appointment with one of our providers to discuss your options.