Post-Excision Radiation Therapy

At keloid doses (12-20 Gy total, delivered superficially), the secondary malignancy risk is small but not zero. Published cohort studies tracking patients for 10-20 years report a handful of radiation-related tumours in a few thousand treated keloids — meaningfully above zero, well below most other adult radiation indications. The consensus is that the risk is acceptable for adults when weighed against a recurrence drop from 70-100% to 10-25%, but it is why radiation is not offered for children, for keloids overlying the breast or thyroid without shielding, or for cosmetic-only cases where less aggressive options are viable. Discuss your specific site with the radiation oncologist before deciding.

Fibroblasts in a fresh surgical wound divide rapidly during the first 24-72 hours as the healing cascade ramps up, and dividing cells are far more sensitive to radiation than resting cells. That window is when a single or short course of low-dose radiation can meaningfully interrupt the signalling that drives keloid regrowth. Wait a week and the same dose no longer does much. This is why protocols demand radiation start within 24-72 hours post-excision, and why it's critical to coordinate surgical and radiation schedules before you commit to either.

Superficial electron beam is the more common, cheaper option and works well for flat, accessible sites like the chest, shoulder, and extremities; it is delivered externally so there are no catheters or additional wound trauma. High-dose-rate brachytherapy uses a thin catheter placed into the wound bed immediately at closure, and delivers radiation from the inside out — this gives a more precise dose distribution for curved or deep sites (earlobes, posterior neck, ear cartilage) but requires a brachytherapy suite and specialized team. Recurrence rates are similar between the two when the dose is properly calibrated; the choice is mostly anatomical and institutional.

The radiation itself is painless — you lie still for a few minutes while a machine delivers the dose, similar to an X-ray. You'll feel nothing during the beam. The discomfort in the first 1-2 weeks is mostly from the surgical wound, not the radiation. Expect the treated skin to become pink or darker, dry, and slightly itchy over the course of the sessions and for a few weeks afterward. Long-term changes include mild persistent hyperpigmentation and occasional small telangiectasias (broken capillaries) at the site.

Sometimes. Coverage is most likely when the keloid is recurrent, symptomatic, or functionally impairing and the radiation is documented as medically necessary adjuvant therapy rather than cosmetic. Ask the surgical and radiation offices to pre-authorize before scheduling surgery — cost ranges from roughly $1,500 for a simple electron-beam course at an academic centre to $8,000+ for brachytherapy at a specialty clinic. If cost is the barrier, alternatives worth discussing with your dermatologist include post-excision triamcinolone + 5-FU protocols, which have a lower recurrence-reduction effect but are more accessible.