Background
Retrospective institutional series (Washington University, St. Louis) reporting outcomes of radiation therapy for epithelial skin cancers (BCC and SCC) treated with definitive or adjuvant RT. Analyses dose-response relationships, local control rates, and complications across multiple fractionation schedules. Large dataset from a single referral center.
Interventions and follow up
Arm A: Various RT dose/fractionation schedules — definitive or adjuvant; no randomizatio
Arm B: Retrospective comparison of fractionation schedules within cohort
Primary endpoint: Local control rate, complication rates by fractionation schedule
mFollow up: Not specified
Arm B: Retrospective comparison of fractionation schedules within cohort
Primary endpoint: Local control rate, complication rates by fractionation schedule
mFollow up: Not specified
Results
Local Control (overall): ~90–95% for well-selected BCC/SCC treated with definitive RT
Dose-response: Higher BED (biologically effective dose) associated with improved LC for larger tumors
Fractionation schedules analyzed: Conventional (2 Gy/fx), hypofractionated (3–5 Gy/fx), and single-fraction palliative
Complication rates: Higher with hypofractionated regimens, particularly for cartilage-containing sites (ear, nose)
Dose-response: Higher BED (biologically effective dose) associated with improved LC for larger tumors
Fractionation schedules analyzed: Conventional (2 Gy/fx), hypofractionated (3–5 Gy/fx), and single-fraction palliative
Complication rates: Higher with hypofractionated regimens, particularly for cartilage-containing sites (ear, nose)
Adverse events
Main adverse events: Acute: erythema, moist desquamation (highest with large fraction sizes). Late: telangiectasia, hypopigmentation, subcutaneous fibrosis. Cartilage necrosis risk with high doses per fraction to ear/nose (recommend <3 Gy/fx for cartilage). Bone involvement: osteonecrosis risk with doses >55 Gy conventional fractionation.
Conclusions
RT achieves excellent local control for BCC and SCC (~90–95%) using conventional fractionation (2 Gy/fx to 60–66 Gy). Hypofractionation is acceptable for uncomplicated lesions but increases late complication risk at sites with cartilage or bone. Dose per fraction should be limited to ≤2.5–3 Gy for lesions overlying cartilage.
Key Limitations
Key Limitations: Retrospective; heterogeneous patient population and RT techniques over long accrual period; no standardized staging; limited data on cosmetic outcomes by fractionation; pre-IMRT era techniques with less conformal RT than modern practice.
Clinical Context
Classic reference for RT dose-fractionation in skin cancer. Informs current practice: conventional 50–66 Gy in 1.8–2 Gy fractions for definitive RT; hypofractionation (35–45 Gy in 2.5–3 Gy/fx) acceptable for elderly patients with uncomplicated lesions; avoid hypofractionation over cartilage to prevent necrosis.
References