The Bottom Line

Radiation therapy is a proven treatment for basal cell carcinoma, squamous cell carcinoma, and certain cases of advanced melanoma. It uses focused beams of energy to destroy cancer cells without cutting. Cure rates are 90–95% for BCC and 85–90% for SCC. It is a particularly good option for tumors in cosmetically sensitive areas or for patients who cannot have surgery. Side effects are mostly limited to the treated area and are manageable.

What Is Radiation Therapy for Skin Cancer?

Radiation therapy delivers precisely aimed beams of high-energy radiation—usually X-rays—to a tumor. The radiation damages the DNA inside cancer cells so severely that the cells cannot reproduce and eventually die. Normal healthy cells nearby are usually able to repair this DNA damage between treatment sessions; cancer cells often cannot. This difference is what makes radiation an effective cancer treatment.

For skin cancer, radiation is primarily used for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). It also plays a role in managing advanced melanoma. It is not used as the main treatment for every patient, but it is a valuable option in specific circumstances.

How Radiation Works: The Science Made Simple

When a radiation beam passes through skin, it creates charged particles that damage the DNA of any cells in its path. This DNA damage triggers cell death over hours to days. Tumors, which grow rapidly and cannot repair DNA well, accumulate more damage than surrounding healthy tissue.

To maximize this difference, radiation is usually given in small daily doses over several weeks (called fractionation). Breaking the total dose into fractions allows healthy skin to partially recover between sessions while cancer cells accumulate lethal damage. A typical schedule involves daily treatments (Monday–Friday) of 1.8–3 Gy per session for 2–6 weeks, totaling 30–60 Gy. Some patients receive fewer, larger fractions (hypofractionation) to shorten the overall treatment course.

Types of Radiation Used for Skin Cancer

X-Ray (Photon) Therapy

Standard external beam radiation uses X-rays generated by a linear accelerator. This is the most widely available type and works well for most skin cancers. Modern versions include intensity-modulated radiation therapy (IMRT), which shapes beams to fit the tumor precisely, and volumetric-modulated arc therapy (VMAT), which rotates around you to deliver radiation from multiple angles—both reduce dose to healthy surrounding tissue.

Proton Therapy

Protons are positively charged particles that can be tuned to stop at a precise depth in tissue (the Bragg peak), depositing most of their energy into the tumor with minimal effect beyond it. This makes proton therapy ideal for skin cancers near the eye, brain, or parotid (salivary) gland. The major limitation is availability and cost—proton centers exist at only a few dozen locations in the United States.

Superficial and Orthovoltage X-Ray

Lower-energy X-rays penetrate only a few millimeters into tissue, making them ideal for thin, surface-level skin cancers. Superficial radiotherapy (SRT) and orthovoltage X-ray therapy are often used in dermatology offices for BCC and SCC in elderly patients or those who prefer to avoid surgery. These machines are simpler and less expensive than linear accelerators.

Who Is a Good Candidate for Radiation Therapy?

Radiation therapy is a good option for you if:

  • You have a BCC or SCC and cannot have surgery due to a health condition, blood thinners, or advanced age
  • Your tumor is in a location where surgery would cause significant disfigurement (eyelid, nose, ear, lip, inner corner of the eye)
  • Surgery was performed but the pathology showed cancer cells at the margins (edges), indicating incomplete removal
  • Your tumor has grown along nerve pathways (perineural invasion), which increases recurrence risk and may benefit from adjuvant radiation after surgery
  • You have multiple skin cancers across a large area that cannot all be surgically removed
  • You have an advanced melanoma with brain or lymph node metastases that benefit from targeted radiation

Radiation is generally avoided in younger patients when surgery is a reasonable option, because irradiated skin has a slightly elevated long-term risk of developing new cancers, and because surgery tends to produce slightly higher cure rates.

Effectiveness by Skin Cancer Type

Basal Cell Carcinoma

Radiation achieves complete tumor clearance in 90–95% of BCC cases. Five-year recurrence rates are 5–10%. Larger tumors (greater than 2 cm) and morpheaform (scar-like) BCC subtypes have higher recurrence rates because they have more irregular edges that are harder to target. Radiation is particularly effective for nodular BCC on the face or eyelids, where the cosmetic outcome from radiation may be better than surgery.

Squamous Cell Carcinoma

Radiation achieves 85–90% five-year local control for small-to-moderate cutaneous SCC. High-risk features—poorly differentiated grade, tumor larger than 4 cm, deep invasion—reduce efficacy. Radiation after surgery for SCC with perineural invasion significantly reduces local recurrence rates.

Melanoma

Melanoma cells are less sensitive to radiation than BCC or SCC cells, so radiation is not used as a primary treatment for early melanoma. However, adjuvant radiation after surgery for thick melanoma (Breslow thickness greater than 4 mm) or node-positive disease reduces local recurrence by 50–70%. Radiosurgery (a single high-dose focused treatment using Gamma Knife or CyberKnife technology) effectively controls individual brain metastases. Combining radiation with checkpoint inhibitor immunotherapy is an active area of research showing early promise.

What to Expect During Treatment

Simulation appointment (planning visit): Before your first treatment, you will have a planning appointment where the radiation team takes measurements, imaging, and possibly marks your skin to guide treatment. A custom mask or mold may be made if you are treating a head or neck tumor.

During treatment: You lie on a padded table. The machine positions itself around you. Treatment delivery takes 5–15 minutes per session, though your total time at the center may be 30–45 minutes with setup. You will not feel the radiation and will not be radioactive afterward.

Frequency: Most courses involve daily sessions, five days a week. Your schedule will depend on your tumor type, size, and treatment approach.

Side Effects and How to Manage Them

All side effects are localized to the treated area unless otherwise noted:

  • Skin redness and inflammation (radiation dermatitis): Develops within 1–2 weeks of starting treatment. Peaks in the second to third week. Your skin team will advise you on gentle cleansers, fragrance-free moisturizers, and wound dressings if the skin breaks down. Most cases heal within a few weeks after treatment ends.
  • Fatigue: Some patients feel generally tired during a radiation course. Rest as needed and stay well hydrated.
  • Hair loss at the treatment site: Hair in the treated area may fall out during treatment. It often regrows, but high-dose treatment can permanently reduce hair in that area.
  • Long-term skin changes: The treated skin may look slightly paler, thinner, or have visible small vessels (telangiectasia) after healing. These changes are usually permanent but cosmetically minor for most patients.
  • Very rare long-term risks: Chronic radiation damage and a very small increase in risk of new cancer in irradiated skin are rare long-term possibilities, especially relevant in younger patients where the risk-benefit calculation may favor surgery.

Radiation Combined with Other Treatments

Radiation increasingly works alongside other therapies:

  • After surgery: Adjuvant radiation reduces recurrence when margins were close or positive, or when perineural invasion was found
  • With immunotherapy: Combining radiation with checkpoint inhibitors (pembrolizumab, nivolumab) is being studied for advanced melanoma. Radiation may make tumors more visible to the immune system, enhancing immunotherapy’s effectiveness
  • For palliation: Radiation reduces pain and bleeding from skin tumors that cannot be fully removed

When to See a Dermatologist or Radiation Oncologist

  • You have a skin cancer diagnosis and want to understand all treatment options, including non-surgical ones
  • Your dermatologist has recommended surgery for a cancer on your face or eyelid and you want to explore whether radiation might be a better fit for your goals
  • Your post-surgery pathology report shows positive margins or perineural invasion
  • You have advanced melanoma with metastases and want to understand radiation’s role in your care plan

Frequently Asked Questions

How does radiation compare to Mohs surgery?

Mohs surgery is the gold standard for high-risk or facial skin cancers, with cure rates exceeding 99%. Radiation achieves 90–95% for BCC and 85–90% for SCC—slightly lower but comparable in good candidates. Mohs is usually preferred when available, but radiation offers excellent results when surgery is not feasible or when the cosmetic outcome of surgery would be poor.

Will I need to stay at a hospital for radiation treatments?

No, radiation therapy for skin cancer is almost always done as an outpatient procedure. You come in for your treatment session and leave afterward. You can generally drive yourself home (unless you feel fatigued), eat normally, and continue daily activities. Most patients work during their radiation course.

What happens if the cancer comes back after radiation?

If a skin cancer recurs in a previously irradiated area, retreatment with more radiation is usually not safe. Surgery (often Mohs surgery) is the next option. Recurrence after radiation tends to be more difficult to manage, which is why choosing the right initial treatment for your situation is so important.

Does insurance cover radiation therapy for skin cancer?

Most insurance plans, including Medicare, cover radiation therapy when it is medically indicated for skin cancer. Coverage for specific techniques (like proton therapy) may vary. Discuss your coverage with your radiation oncology team’s billing department before starting treatment.

References

  1. Mendenhall WM, Amdur RJ, Hinerman RW, et al. Radiotherapy for cutaneous squamous and basal cell carcinomas of the head and neck. Laryngoscope. 2009;119(10):1994-1999.
  2. Cognetta AB, Howard BM, Heaton HP, et al. Superficial X-ray in the treatment of basal and squamous cell carcinomas. J Am Acad Dermatol. 2012;67(6):1235-1241.
  3. Schulte KW, Lippold A, Auras C, et al. Soft X-ray therapy for cutaneous basal cell and squamous cell carcinomas. J Am Acad Dermatol. 2005;53(6):993-1001.
  4. Henderson MA, Burmeister BH, Ainslie J, et al. Adjuvant lymph-node field radiotherapy versus observation only in patients with melanoma at high risk of further lymph-node field relapse. Lancet Oncol. 2015;16(9):1049-1060.
  5. Ballo MT, Ang KK. Radiotherapy for cutaneous malignant melanoma: rationale and indications. Oncology (Williston Park). 2004;18(1):99-107.
  6. Siker ML, Mehta MP. Radiosurgery for brain metastases from melanoma. Am J Clin Oncol. 2006;29(3):296-302.

Trusted Resources

Always consult a board-certified dermatologist or radiation oncologist for personalized treatment recommendations. This article is for educational purposes and does not replace individualized medical advice.