Adjuvant Radiotherapy for Palpable Melanoma Metastases to the Groin: When to Irradiate?

Purpose To determine the efficacy of and criteria for postoperative radiotherapy (PORT) in patients with palpable melanoma metastases to the groin. Methods and Materials Patients with palpable metastases to the groin who were treated with therapeutic nodal dissection during 2000 to 2006 were identified in a prospective institutional database. Results In 101 patients, 103 therapeutic nodal dissections were performed; 37 of these were treated with PORT to a median equivalent dose (eqTD2 ) of 50.6 Gy (range, 50–72 Gy). In the surgery-only and PORT groups, 2-year regional control rates were 86% (95% confidence interval [CI] 76–95%) and 91% (95% CI, 81–100%), respectively ( p = 0.395). Of five recurrences in radiation-treated patients, four were of dermal type, and in three of these cases, no bolus over the operative scar was used. PORT improved 2-year regional control (46% [95% CI, 11–82%] vs. 82% [95% CI, 63–100%], p = 0.022) among patients in which the sum of risk factors present ( i.e. , risk factor score) was ≥2. In multivariate analysis, risk-factor score (