When can radiotherapy be started after a split-thickness skin graft (STSG)?

Timing of Radiotherapy After Split-Thickness Skin Grafts

Radiotherapy can be safely initiated 6-8 weeks after split-thickness skin graft (STSG) placement, provided the graft has healed adequately and is placed on a well-vascularized tissue bed. This timing allows for sufficient graft take and wound healing while not unduly delaying necessary oncologic treatment.

Factors Affecting Timing Decision

Graft Healing Status

• Complete epithelialization of the STSG should be confirmed before starting radiotherapy
• Absence of wound complications (infection, partial graft loss, drainage)
• Stable wound with no evidence of graft contracture

Underlying Tissue Bed Quality

• STSGs placed on well-vascularized muscle beds tolerate radiotherapy better 1
• Grafts placed directly on bone, tendon, or poorly vascularized tissue have higher risk of complications

Radiation Dose Considerations

• Higher doses (≥25 Gy) are associated with increased risk of graft failure 2
• Fractionated regimens are better tolerated than single high-dose treatments

Evidence-Based Protocol

1. Initial post-graft period (0-4 weeks):

   • Focus on wound care and monitoring graft take
   • Keep dressing undisturbed for first 48 hours unless leakage occurs
   • Regular wound assessment for signs of infection or graft failure

2. Pre-radiation assessment (4-6 weeks post-graft):

   • Evaluate complete graft take and wound maturity
   • Ensure absence of complications before proceeding with radiotherapy

3. Safe window for radiotherapy initiation (6-8 weeks):

   • Median time to radiotherapy after grafting in successful cases is 8 weeks 1
   • Minimum recommended time is 6 weeks if graft has healed well

Special Considerations

Wound Bed Preparation

• If radiotherapy is anticipated, STSG should ideally be placed on well-vascularized muscle beds 1
• Use of wound contact layers between STSG and underlying tissue may help reduce complications 3

Monitoring During Radiotherapy

• Regular assessment for radiation dermatitis
• Maintain hygiene and gently clean the irradiated area
• Avoid applying topical moisturizers immediately before radiation sessions as they can cause a bolus effect 3

Management of Complications

• Minor skin graft loss from radiotherapy can often be treated conservatively 1
• Complete graft failure requiring regrafting is rare when proper timing is observed

Pitfalls to Avoid

1. Starting radiotherapy too early (< 6 weeks) increases risk of graft failure and wound complications
2. Delaying radiotherapy unnecessarily may compromise oncologic outcomes
3. Failing to consider the quality of the underlying tissue bed when planning treatment
4. Not accounting for higher risk in patients with comorbidities (diabetes, peripheral vascular disease, chronic steroid use) 4

For patients with known risk factors for poor wound healing, consider regrafting techniques or alternative reconstruction methods if radiotherapy is anticipated.