Superficial Radiation Therapy (SRT) for Keloids in Singapore: An Evidence-Based Look at Tissue Risks and Why I Prefer Non-Ionising Protocols in My Practice

Hello, friends and patients. I'm Dr Wan Chee Kwang, Founder and Medical Director of 1Aesthetics, Medical & Surgery in Singapore. If you've been following my clinical deep dives on keloid scar removal, keloid surgery techniques, ear keloid surgery, and keloid injection protocols, you'll know I'm a confessed geek when it comes to the microscopic biology of wound healing and tissue repair.

Today, we're tackling one of the most common questions that arrives in my consultation room from patients exploring keloid removal in Singapore: what about radiation therapy?

Let me be transparent up front: I do not use superficial radiation therapy (SRT) in my own clinical practice. That's a deliberate choice based on how I read the evidence and how I weigh long-term tissue health against short-term recurrence numbers, particularly for the Fitzpatrick III–V skin types I see most often in Singapore. SRT is a legitimate modality offered by other practitioners, and I do not quarrel with how they use it. What I want to do here is walk you transparently through the published data — and explain why my own protocols at 1Aesthetics rely on judicious surgery where indicated, followed by a multi-drug intralesional suppression matrix, with lasers used selectively rather than routinely.

This article reflects the same evidence-based ethos I apply across my acne scar treatment and broader scar management practice. Let's set aside the marketing and put on our lab coats to examine the data.

This article is for educational purposes only and does not constitute medical advice. Individual outcomes vary, and a qualified medical practitioner should always assess treatment suitability.

Quick Summary (TL;DR)

Superficial Radiation Therapy (SRT) is an adjuvant — not a standalone — option used after surgical excision of keloids to reduce recurrence. The most recent meta-analysis reports pooled recurrence rates of approximately 13.5% with surgery + radiotherapy and approximately 12.2% with laser + intralesional pharmacotherapy — clinically comparable figures (Fu S et al., International Wound Journal, 2024). SRT carries documented risks, including pigmentary change, telangiectasia, atrophy, hair loss, possible chondroradionecrosis at cartilage-adjacent sites, and a small theoretical risk of secondary malignancy. Dr Wan does not use SRT in his clinical practice at 1Aesthetics. His post-surgical pathway relies primarily on a multi-drug intralesional suppression matrix (without routine post-op lasers or radiation), while lasers play a more prominent role in the non-surgical pathway for keloids managed without excision. Patients seeking SRT can be referred to centres that offer it.

What Is Superficial Radiation Therapy (SRT)?

Superficial radiation therapy uses low-energy kilovoltage X-rays (typically 50–100 kVp) to target the outermost layers of skin. It was originally developed for non-melanoma skin cancers and has since been adapted as an adjuvant — an "add-on" — to reduce keloid recurrence after surgical excision.

The keyword is "superficial." SRT units are calibrated so that most of the energy is deposited within the first few millimetres of skin, unlike the deep megavoltage radiotherapy used for internal cancers. This limits dose to deeper organs, but it does not change the underlying physics: you are still exposing healthy tissue — melanocytes, microvasculature, hair follicles, and adjacent cartilage — to ionising radiation.

For readers new to keloid management more broadly, our pillar guide on keloid scar removal in Singapore explains how vascular lasers, fractional ablative CO₂ lasers, and surgery fit together. If you're earlier in your journey and still asking whether your scar even needs treatment, our article "Scar Removal in Singapore: Should I Get It?" is a useful starting point. And if your keloid sits specifically on the ear — a particularly common and challenging site — our ear keloid surgery deep-dive on recurrence prevention addresses cartilage-related considerations directly.

How SRT Works on Keloids — The Underlying Biology

To understand why SRT performs well in some scenarios and poorly in others, we need to revisit how keloids form. As discussed in our piece on whether keloids can be prevented, keloids arise from disordered wound healing: prolonged inflammation, dysregulated TGF-β signalling, and excessive deposition of dense, disorganised type I and III collagen by hyperactive fibroblasts (Limandjaja GC et al., Frontiers in Cell and Developmental Biology, 2020).

Ionising radiation primarily targets actively dividing cells by inducing double-strand DNA breaks. In keloid biology, this produces a sharp dichotomy:

• Early, rapidly dividing fibroblasts (e.g., in the immediate post-surgical wound) are radiation-sensitive.
• Mature, quiescent fibroblasts in old, bulky keloids are comparatively radioresistant.

This distinction underpins why SRT is studied predominantly as a post-operative adjuvant and why it tends to underperform when used as a standalone treatment for established keloids (Ogawa R, Plastic and Reconstructive Surgery, 2022).

Clinical Scenarios: Where SRT Is Studied (and Where It Isn't)

Scenario 1: Post-Operative Adjuvant SRT — The "Physical Reset"

For large, bulky keloids — think hanging earlobe keloids or thick chest plaques — many algorithms recommend a "physical reset" first by surgically clearing the bulk of the lesion. As we explore in "Is Keloid Scar Removal Surgery Worthless?", surgery alone has historically been associated with significant recurrence, depending on technique and tension management.

To reduce recurrence, SRT is typically initiated within 24–72 hours of surgery and delivered over several fractions. Because the fresh wound is filled with rapidly dividing immature fibroblasts, radiation suppresses regrowth more efficiently than when applied to mature scar tissue.

The published evidence varies by series and protocol, but consistently shows meaningful reductions over surgery alone:

• A meta-analysis by Mankowski P et al. (Plastic and Reconstructive Surgery, 2017) reported that post-operative radiotherapy was associated with a recurrence rate of approximately 22%, compared to approximately 37% with radiotherapy alone — supporting the post-operative adjuvant model rather than monotherapy.
• A radiobiological pooled analysis by Kal HB & Veen RE (Strahlentherapie und Onkologie, 2005) suggested that biologically effective doses (BED) above ~30 Gy correlated with recurrence rates under 10% in selected series.
• A 2024 systematic review and meta-analysis comparing excision plus radiotherapy versus laser plus intralesional therapy reported a pooled recurrence rate of 13.5% for the surgery + radiotherapy group (Fu S et al., International Wound Journal, 2024).

In other words, the recurrence range across the literature is wide — roughly 10–22% depending on which series and which dosing protocol you look at — with the most recent pooled meta-analytic estimate sitting at 13.5%. When correctly dosed and timed, SRT can offer meaningful recurrence control. The reason I personally don't use it comes down to the long-term tissue trade-offs, which I'll come to below.

Scenario 2: Primary SRT Monotherapy — Why It Underperforms

Patients sometimes ask, "Dr Wan, can I skip surgery completely and just radiate the keloid?"

In theory, yes. In practice, mature keloids are dense collagen "bricks" populated by relatively quiescent cells, far less sensitive to radiation than the proliferating fibroblasts of a fresh wound. The Mankowski et al. (2017) meta-analysis put recurrence with radiotherapy alone at around 37%, and current treatment algorithms do not support radiation monotherapy as a first-line option for established keloids (Ogawa R, Plast Reconstr Surg, 2022; Berman B et al., Dermatologic Surgery, 2017). For mature keloids, modalities such as laser-plus-injection protocols typically offer a more practical pathway.

The Tissue Risks That Inform My Clinical Decision

Here is the honest answer to "why don't you use SRT, Dr Wan?": for the patient population I treat, the long-term tissue trade-offs of ionising radiation feel disproportionate to the marginal recurrence benefit over well-executed non-ionising protocols.

1. Pigmentary Changes in Melanin-Rich Skin

Singapore's population largely falls within Fitzpatrick Skin Types III–V, with greater baseline melanin production. Radiation can affect melanocytes, leading to:

• Hyperpigmentation (darkening)
• Hypopigmentation (loss of pigment)
• Mottled dyschromia

Hyperpigmentation is the most frequently reported adverse event in post-operative keloid radiotherapy series (McKeown SR et al., British Journal of Radiology, 2015; Fu S et al., Int Wound J, 2024). For a benign condition treated for cosmetic and symptomatic reasons, the risk of long-term or permanent pigment change is a meaningful consideration — one I factor heavily into my approach to keloid prevention and treatment planning for Asian skin.

2. Cartilage Risk and Chondroradionecrosis

Keloids commonly form on the ear, where thin skin overlies avascular cartilage. As I discuss in detail in our ear keloid surgery and recurrence prevention article, cartilage depends entirely on the surrounding skin's microvasculature for oxygen and nutrient diffusion.

Radiation can damage endothelial cells and compromise the microvascular network. In high-risk scenarios, this can lead to chondroradionecrosis — cartilage death — manifesting as chronic pain, ulceration, or structural deformity. Although the absolute risk with modern SRT dosing is low, it is not zero, and is particularly relevant in younger patients with decades ahead of them.

3. Skin Atrophy, Telangiectasia, Ulceration, and Permanent Hair Loss

SRT can also weaken the structural integrity of normal skin within the treatment field (Hymes SR et al., Journal of the American Academy of Dermatology, 2006). Late effects described in the radiotherapy literature include:

• Dermal atrophy and telangiectasia — thin, fragile skin with dilated vessels
• Delayed ulceration that may be slow to heal
• Permanent loss of hair follicles within the irradiated field

These are dose- and site-dependent, but they are part of why I prefer to keep ionising radiation off my clinical menu.

4. Theoretical Risk of Secondary Malignancy

Any application of ionising radiation to benign tissue carries a theoretical lifetime risk of radiation-induced malignancy, particularly in younger patients. McKeown et al. (Br J Radiol, 2015) concluded that this risk is small with modern benign-disease protocols, but emphasised that the risk-benefit balance must be carefully considered in younger adults — the very demographic most often affected by keloids. For a benign cosmetic condition, I personally prefer to avoid that equation entirely if a comparably effective non-ionising path exists.

My Two-Track Approach at 1Aesthetics

A practical point that often gets glossed over in keloid articles: the right tool depends on whether surgery is part of the plan. Different keloids call for different sequencing. I broadly run two tracks, and this is why my use of lasers looks different from what readers might expect.

Track A — The Post-Surgical Pathway: Surgery + Multi-Drug Intralesional Suppression

For keloids where surgery is clinically indicated — typically large, pedunculated, or bulky lesions such as hanging earlobe keloids — the workflow looks like this:

1. Carefully planned keloid surgery, often using techniques such as intralesional fillet flaps to preserve skin coverage and minimise wound tension — a known driver of recurrence, as we explore in "Is Keloid Scar Removal Surgery Worthless?" (Ogawa R, Plast Reconstr Surg, 2022).
2. Early initiation of a multi-drug intralesional suppression matrix in the perioperative and early post-operative period to suppress the rapidly proliferating fibroblast population in the healing wound.
3. Structured follow-up with serial intralesional injections, with intervals and drug combinations adjusted dynamically based on the scar's behaviour over time.

A point I want to be clear about: I do not routinely use lasers after keloid surgery. Some readers may expect a surgery → laser → injection sequence, but in my hands, the post-surgical workflow does not generally need lasers as a standard step. The reasons:

• A freshly excised wound is already "reset." The dense collagen brick that lasers help break down is no longer there in the same form.
• The key biological window post-surgery is the proliferative phase, where rapidly dividing fibroblasts are most responsive to pharmacological suppression — corticosteroids, antimetabolites such as 5-fluorouracil (Khan MA et al., J Pak Med Assoc, 2014), and (in tension-prone sites) botulinum toxin type A (Bi M et al., Aesthetic Plastic Surgery, 2019).
• Adding lasers to a healing surgical wound introduces additional thermal and inflammatory stimuli that I'd rather avoid in the early healing phase, particularly in melanin-rich skin where post-inflammatory hyperpigmentation risk is elevated.

If the post-surgical scar later develops persistent erythema, hyperpigmentation, or residual textural irregularity — or shows early signs of recurrence despite injections — then lasers (vascular and/or fractional ablative CO₂) may be added selectively as a second-line refinement. They are a tool I reach for when indicated, not a default step. I also do not provide SRT, and I do not use it in my own protocols. For patients who, after consultation, decide they would like to pursue an SRT-based pathway, I am happy to discuss referral to centres with dedicated radiation oncology services.

Track B — The Non-Surgical Pathway: Lasers + Multi-Drug Intralesional Therapy

For keloids where surgery is not indicated or not preferred — for example, smaller or flatter lesions, broad-based plaques, or patients who want to avoid an excision — lasers play a much more prominent role. This pathway draws on the same multi-modal philosophy underlying my scar removal and broader keloid removal practice.

1. Vascular Laser Targeting

I use vascular lasers (pulsed-dye or long-pulsed Nd:YAG) to selectively heat and collapse the abnormal microvasculature feeding the keloid (Alster TS, Lasers in Surgery and Medicine). The principle is similar to the vascular targeting used in acne scar treatment, but adapted for keloid biology — addressing pathological vessels while preserving the broader microvascular architecture (an important difference from radiation, which can compromise the entire microvascular bed indiscriminately).

2. Fractional Ablative CO₂ Laser Remodelling

I use fractional ablative CO₂ lasers to create microscopic columns within the dense collagen matrix. This:

• Disrupts rigid scar architecture
• Softens the keloid over successive sessions
• Enhances penetration of subsequently delivered intralesional medications (laser-assisted drug delivery)

This same principle is well-established in our acne scar treatment protocols and adapts well to keloid remodelling (Waibel JS et al., JAMA Dermatology, 2013). For readers wondering whether their acne-related concerns have crossed into scar territory, our companion piece on the seven signs you may benefit from acne scar removal is a useful self-assessment, and our discussion of acne and psychological well-being addresses the emotional weight of visible skin conditions.

3. Multi-Drug Intralesional Matrix: Beyond Steroids

Immediately after laser remodelling — when the scar is most receptive — I deliver a customised intralesional combination tailored to each patient. Depending on clinical indication, this may include:

• Corticosteroids (intralesional triamcinolone) to dampen inflammation and collagen synthesis (Berman B et al., Dermatol Surg, 2017)
• Antimetabolites such as 5-fluorouracil to reduce fibroblast hyperactivity (Khan MA et al., 2014)
• Botulinum toxin type A in mechanically tense areas to reduce tension forces that drive keloid growth (Bi M et al., Aesthetic Plast Surg, 2019)
• Bleomycin in selected refractory lesions where clinically appropriate (Saray Y, Güleç AT, Int J Dermatol, 2005)

I discuss the rationale for combining drug classes — and why this can improve outcomes while moderating steroid dose — in our article "Keloid Injections in Singapore: Beyond Steroid Therapy".

Why Steroid Monotherapy Often Isn't Enough (Either Track)

Whether in Track A or Track B, intralesional triamcinolone alone has its limits. Recurrence after steroid monotherapy remains substantial — reported rates range from approximately 9% to 50%, depending on dosing, intervals, and lesion type (Berman B et al., 2017). In real-world Singapore practice, many patients I see for keloid injections have already had steroid monotherapy elsewhere and either plateaued or rebounded. This is why I rarely rely on steroids alone, regardless of which track a patient is on.

Comparable Recurrence Numbers Without Ionising Radiation

The 2024 meta-analysis by Fu S et al. (International Wound Journal) is informative here:

• Surgical excision + adjuvant radiotherapy: pooled recurrence ~13.5%
• Laser + intralesional steroid injections: pooled recurrence ~12.2%

Side-effect profiles differed: the laser + injection group reported less hyperpigmentation but more atrophy and telangiectasia. Every modality carries its own profile. The reason I lean toward non-ionising pathways is that their risks are, in my experience, more manageable and reversible than the late effects of ionising radiation in melanin-rich skin and cartilage-adjacent sites.

Comparing Modalities Side-by-Side

Why I Personally Don't Use SRT — A Frank Summary

I want to be clear: SRT is a legitimate, evidence-based modality. Practitioners and centres that offer it, and patients who choose it after informed consent, are making a reasonable decision based on the data.

My personal reasons for not using it in my own practice are:

1. Comparable recurrence numbers exist without ionising radiation. Published meta-analytic data put laser + injection recurrence (~12.2%) within a hair of surgery + radiotherapy (~13.5%) (Fu S et al., Int Wound J, 2024), and well-executed surgery + multi-drug injection protocols are also competitive in my hands.
2. My patient demographic skews Fitzpatrick III–V. Pigment-related radiotherapy adverse events are a significant consideration in melanin-rich skin (McKeown SR et al., Br J Radiol, 2015).
3. Many of my keloid cases are cartilage-adjacent (earlobes, helix). Microvascular and chondroradionecrosis risk weighs more heavily here, as I discuss in our ear keloid surgery and recurrence prevention article.
4. Younger patients have decades for theoretical risks to play out. Even small radiation-induced malignancy probabilities matter when the underlying condition is benign (Ogawa R et al., Radiation Oncology, 2011; McKeown SR et al., 2015).
5. Non-ionising side effects are generally more manageable and reversible than the late effects of ionising radiation, allowing for course corrections over time.

Other clinicians may weigh these factors differently. That's reasonable. This is simply how I weigh them, and how I've designed my practice.

Frequently Asked Questions

Does Dr Wan use SRT for keloids at 1Aesthetics? No. I do not use superficial radiation therapy in my own clinical practice. Patients who, after consultation, would like to pursue an SRT-based pathway can be referred to centres with dedicated radiation oncology services.

Does Dr Wan use lasers after keloid surgery? Not routinely. My post-surgical pathway relies primarily on a multi-drug intralesional suppression matrix. Lasers may be added selectively as a second-line refinement if persistent erythema, hyperpigmentation, residual textural irregularity, or early recurrence develops despite injections, but they are not a default step in the immediate post-surgical period.

Is SRT a cure for keloids? No keloid treatment can guarantee a cure. The published literature reports recurrence rates ranging from approximately 10% to 22% with post-excisional SRT protocols, depending on dosing and series, with the most recent meta-analysis pooling at 13.5% (Mankowski P et al., Plast Reconstr Surg, 2017; Fu S et al., 2024).

Can SRT be used without surgery? Current evidence does not support radiation monotherapy as a first-line treatment for established keloids; recurrence with radiotherapy alone has been reported at around 37% in pooled data (Mankowski P et al., 2017; Ogawa R, Plast Reconstr Surg, 2022).

Is laser plus injection therapy as effective as surgery plus radiotherapy? The Fu S et al. (2024) meta-analysis reported comparable pooled recurrence rates (12.2% vs 13.5%), with differing side-effect profiles. Treatment choice depends on individual patient factors.

Are these treatments suitable for darker skin types? Patients with Fitzpatrick III–V skin require treatment plans that account for higher melanocyte sensitivity. A clinical consultation is needed to determine suitability, and our article on keloid prevention addresses skin-type-specific considerations in more detail.

What if I've already had steroid injections that didn't work? This is one of the most common scenarios I see. Steroid monotherapy has reported recurrence rates of 9–50% (Berman B et al., Dermatol Surg, 2017), so plateauing or rebounding is well-documented. Our article on keloid injections beyond steroid therapy explains how multi-drug protocols can build on what didn't work alone.

What should I do if I'm not sure my scar is a keloid? Start with our overview article "Scar Removal in Singapore: Should I Get It?", then arrange a clinical consultation for proper assessment.

The 1Aesthetics Philosophy: Tailored, Evidence-Driven, Patient

Patients often ask, "Dr Wan, what's your exact step-by-step keloid protocol? Which lasers and which injection mix?"

I could give you a rough outline — and our articles on scar removal in Singapore, keloid surgery, ear keloid surgery, recurrence prevention, and keloid injections sketch the framework — but rigid, one-size-fits-all recipes aren't appropriate in keloid medicine. An earlobe keloid sitting on cartilage behaves very differently from a chest keloid under constant mechanical tension, or a jawline keloid arising from acne.

I deliberately maintain a fluid, individualised approach:

• I reassess each scar's texture, colour, and symptoms at every visit.
• I adjust laser parameters, injection components, and sequencing dynamically based on how the tissue is responding — not on a fixed template.
• I keep ionising radiation off my own clinical menu, while remaining open to referral for patients who, after a full discussion of risks and benefits, decide SRT is the right path for them.

Keloids are stubborn. My job is to be patient and methodical — pairing wound biology with a thoughtful surgical approach, a nuanced multi-drug suppression matrix, and lasers when (and only when) they add value. The goal isn't just to flatten the scar today; it's to give your tissue the best chance of staying flat, supple, and healthy for decades to come.

If you'd like to learn more about our approach, you can read further on our keloid removal, ear keloid surgery, recurrence prevention, keloid surgery, keloid injection, and keloid prevention pages, or contact 1Aesthetics, Medical & Surgery to arrange a clinical consultation in Singapore.

Information presented reflects published literature current as of the review date. Individual treatment outcomes vary, and all treatments carry potential side effects, which will be discussed during clinical consultation.

Selected References

1. Ogawa R. The Most Current Algorithms for the Treatment and Prevention of Hypertrophic Scars and Keloids. Plastic and Reconstructive Surgery. 2022.
2. Fu S, et al. Comparison of Surgical Excision Followed by Adjuvant Radiotherapy and Laser Combined with Steroids for the Treatment of Keloids: A Systematic Review and Meta-analysis. International Wound Journal. 2024.
3. Mankowski P, Kanevsky J, Tomlinson J, Dyachenko A, Luc M. Optimizing Radiotherapy for Keloids: A Meta-analysis. Plastic and Reconstructive Surgery. 2017.
4. Limandjaja GC, Niessen FB, Scheper RJ, Gibbs S. The Keloid Disorder: Heterogeneity, Histopathology, Mechanisms, and Models. Frontiers in Cell and Developmental Biology. 2020.
5. Berman B, Maderal A, Raphael B. Keloids and Hypertrophic Scars: Pathophysiology, Classification, and Treatment. Dermatologic Surgery. 2017.
6. Hymes SR, Strom EA, Fife C. Radiation Dermatitis: Clinical Presentation, Pathophysiology, and Treatment. Journal of the American Academy of Dermatology. 2006.
7. Waibel JS, Wulkan AJ, Shumaker PR. Treatment of Hypertrophic Scars Using Laser and Laser-Assisted Drug Delivery. JAMA Dermatology. 2013.
8. Khan MA, Bashir MM, Khan FA. Intralesional Triamcinolone Alone and in Combination with 5-Fluorouracil for the Treatment of Keloid and Hypertrophic Scars. Journal of the Pakistan Medical Association. 2014.
9. Kal HB, Veen RE. Biologically Effective Doses of Postoperative Radiotherapy in the Prevention of Keloids. Strahlentherapie und Onkologie. 2005.
10. McKeown SR, Hatfield P, Prestwich RJD, Shaffer RE, Robinson MH. Radiotherapy for Benign Disease; Assessing the Risk of Radiation-Induced Cancer. British Journal of Radiology. 2015.
11. Bi M, et al. The Efficacy of Botulinum Toxin Type A in the Treatment of Keloids. Aesthetic Plastic Surgery. 2019.
12. Saray Y, Güleç AT. Treatment of Keloids and Hypertrophic Scars with Dermojet Injections of Bleomycin. International Journal of Dermatology. 2005.
13. Ogawa R, et al. Postoperative Radiation Protocol for Keloids and Hypertrophic Scars. Radiation Oncology. 2011.