Background
Retrospective single-institution analysis (MD Anderson Cancer Center) of outcomes of adjuvant RT to axillary lymph node basins in patients with Stage III melanoma after complete axillary lymph node dissection. Large cohort study evaluating regional control, late toxicity (especially lymphedema), and survival. RT: 30 Gy in 5 fractions (6 Gy/fx) standard MDACC schedule.
Interventions and follow up
Arm A: CLND + adjuvant RT 30 Gy in 5 fractions to axillary basi
Arm B: N/A — single-arm retrospective (historical surgery-alone comparisons referenced)
Primary endpoint: Axillary regional relapse, lymphedema rate
mFollow up: Not specified
Arm B: N/A — single-arm retrospective (historical surgery-alone comparisons referenced)
Primary endpoint: Axillary regional relapse, lymphedema rate
mFollow up: Not specified
Results
Axillary Regional Relapse: ~5–10% with adjuvant RT (vs. historical 20–30% without RT for high-risk features)
Lymphedema (grade 2–3): ~20–25%; risk lower with axillary vs. inguinal fields
5-Year OS: Consistent with Stage III melanoma prognosis; no OS benefit vs. surgery alone demonstrated in this retrospective series
Lymphedema (grade 2–3): ~20–25%; risk lower with axillary vs. inguinal fields
5-Year OS: Consistent with Stage III melanoma prognosis; no OS benefit vs. surgery alone demonstrated in this retrospective series
Adverse events
Main adverse events: Lymphedema: grade 2–3 in ~20% (lower than inguinal); transient brachial plexopathy rare; skin fibrosis; radiation pneumonitis risk with lung in field (kept minimal with technique).
Conclusions
Adjuvant RT (30 Gy/5 fx) to the axillary basin after CLND achieves excellent regional control (~5–10% relapse) in high-risk Stage III melanoma with acceptable lymphedema rates (~20%). Provides important institutional evidence supporting the ANZNTG 01.02 RCT findings in the axillary sub-site.
Key Limitations
Key Limitations: Retrospective; no randomization; pre-immunotherapy era; selection bias toward higher-risk features receiving RT; lymphedema assessment not standardized; limited follow-up for very late toxicities.
Clinical Context
Supports adjuvant RT for axillary melanoma with high-risk nodal features (≥2 nodes, extranodal extension, node ≥3 cm). Axillary fields have better lymphedema rates than inguinal, making the risk-benefit ratio more favorable. The ANZNTG 01.02 trial confirmed the regional control benefit in a randomized setting.