Superficial Radiation Therapy (SRT)
Introduction to Superficial Radiation Therapy (SRT)
Superficial Radiation Therapy (SRT) is a non-invasive treatment that utilizes low-energy X-rays to target and treat specific skin conditions. This therapy is primarily used for treating non-melanoma skin cancers, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). SRT is also effective in treating certain types of keloids, which are raised scars that form after skin injuries.
Unlike traditional radiation therapy, SRT penetrates only the top layers of the skin, which makes it a suitable option for treating skin conditions that are confined to the skin's surface. It offers a painless alternative to surgical procedures, with minimal scarring and a quick recovery time.
How Superficial Radiation Therapy Works
SRT works by directing low-energy X-rays at the affected area. These X-rays penetrate just below the skin's surface, targeting the abnormal cells while minimizing damage to the surrounding healthy tissue. The radiation disrupts the DNA in the cancerous or abnormal cells, preventing them from growing and multiplying. Over time, these cells die off, and the body naturally eliminates them.
The precision of SRT allows for the treatment of skin lesions in cosmetically sensitive areas, such as the face, ears, and neck, where surgical scars might be undesirable.
Indications for SRT
SRT is commonly recommended for treating the following conditions:
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, often appearing as a pearly or waxy bump. SRT is particularly effective for BCC lesions that are superficial and located in areas where surgery may be challenging or cosmetically unappealing.
Squamous Cell Carcinoma (SCC): SCC is another type of skin cancer that can appear as a firm, red nodule or a flat lesion with a scaly, crusted surface. SRT can be a good option for SCC, especially in older patients or those with medical conditions that make surgery risky.
Keloids: Keloids are raised, thickened scars that can be painful or itchy. SRT can be used as an adjunct to surgical removal of keloids to reduce the risk of recurrence.
When SRT is Recommended
SRT may be recommended in the following situations:
Cosmetically Sensitive Areas: For lesions on the face, neck, or other areas where surgical scars might be a concern, SRT offers a non-invasive alternative with minimal scarring.
Patients with Health Concerns: SRT is a good option for patients who have underlying health conditions that make surgery risky, such as bleeding disorders or cardiovascular disease.
Older Adults: For older adults who may have a higher surgical risk or who prefer a less invasive treatment, SRT can be an effective option.
Patients with Multiple Skin Cancers: Up to 3 sites can be treated at a time. This is a nice option for people who have already had multiple skin cancers removed in the past. Typically with surgery only one area can be treated at a time.
When Surgery, Such as Mohs Surgery, May Be a Better Option
While SRT is effective for certain patients and conditions, there are many instances where surgical options, such as Mohs surgery, might be more appropriate:
Aggressive or Invasive Tumors: Mohs surgery is often recommended for skin cancers that are aggressive or have spread deeper into the skin. Mohs surgery allows for the precise removal of cancerous tissue while preserving as much healthy tissue as possible.
Recurrent Skin Cancers: For skin cancers that have recurred after previous treatments, Mohs surgery may be preferred due to its high cure rate and ability to assess the margins of the removed tissue in real time.
Younger Patients: In younger patients, where long-term side effects of radiation might be a concern, surgery is often considered the better option.
Large or Deep Lesions: For large or deep lesions, surgery may be more effective in ensuring complete removal of the cancerous tissue.
The SRT Procedure
Pre-Treatment Consultation: Before starting SRT, you'll have a consultation with your dermatologist to assess the lesion and discuss your treatment options. During this consultation, the dermatologist will explain the SRT procedure, including what to expect during and after treatment. You may be advised to avoid certain medications or skin products before the procedure.
Treatment Sessions:
Duration and Frequency: SRT sessions typically last a few minutes. Depending on the condition being treated, you may require multiple sessions, usually 15-20, spread out over several weeks.
Comfort During Treatment: The procedure is painless, and most patients do not require any form of anesthesia. You will simply sit or lie comfortably while the SRT machine is positioned over the treatment area.
Post-Treatment Protocol:
Immediate Effects: After each session, you may experience mild redness or irritation in the treated area, similar to a mild sunburn. These side effects are usually temporary.
Skin Care: It is important to follow your dermatologist's instructions for skin care after each session. This may include using gentle moisturizers or ointments to soothe the skin.
Expected Results and Effectiveness
SRT has been shown to be highly effective in treating non-melanoma skin cancers, with cure rates comparable to surgical options for appropriate cases. Most studies show a 99% cure rate. Most patients experience a gradual reduction in the size of the lesion over the course of treatment. The final cosmetic result is typically very good, with minimal scarring.
For keloids, SRT can significantly reduce the risk of recurrence when used in conjunction with surgical removal.
Risks and Side Effects
While SRT is generally safe, it does carry some risks, as with any medical treatment:
Common Side Effects:
Redness and Irritation: Mild redness, irritation, or peeling of the skin in the treated area is common and usually resolves on its own.
Dryness: The treated skin may become dry and flaky. Using a gentle moisturizer can help alleviate this.
Hair Loss: Permanent hair loss will occur in the treated area if it is near a hair-bearing region.
Rare but Serious Risks:
Changes in Skin Texture or Color: In some cases, the treated area may develop changes in skin texture or color, such as a lighter or darker spot.
Non Healing Sores: This is more common on areas that have worse circulation like on the leg.
Long-Term Safety: The long-term safety of SRT is well-documented, but it is important to discuss any concerns with your dermatologist, especially if you are undergoing treatment in a cosmetically sensitive area or if you have a history of radiation exposure. There is a 3-6% risk of a secondary skin cancer in the affected area 30-40 years after the treatment.
Post-Treatment Care and Long-Term Follow-Up
Skin Care Guidelines:
Moisturizing: Keep the treated area moisturized with a gentle product like Vaseline or Aquaphor to promote healing.
Sun Protection: It is crucial to protect the treated area from sun exposure by using a broad-spectrum sunscreen and wearing protective clothing.
Avoid Irritants: Avoid using harsh skincare products or treatments on the treated area until it has fully healed.
Long-Term Monitoring: After completing your SRT treatment, regular follow-up appointments with your dermatologist are essential. These visits allow your dermatologist to monitor the treated area for any signs of recurrence or new skin lesions.
Frequently Asked Questions (FAQ)
Is SRT safe? Yes, SRT is a safe and effective treatment option for certain skin conditions. It has been used for decades with a well-established safety profile.
How does SRT compare to surgery? SRT is a non-invasive alternative to surgery that is particularly useful for patients who cannot undergo surgery or for treating lesions in cosmetically sensitive areas. However, surgery may be preferred for more aggressive or recurrent skin cancers.
Will SRT leave a scar? SRT typically results in minimal scarring, especially compared to surgical options. However, the final cosmetic outcome can vary depending on the location and size of the treated lesion.
How should I prepare for my SRT sessions? Your dermatologist will provide specific instructions, but generally, you should avoid using certain skin products before treatment and protect your skin from the sun.
What can I expect after each session? You may experience mild redness or irritation, but this should resolve within a few days. Follow your dermatologist's post-treatment care instructions to ensure the best results.