A critical assessment of adjuvant radiotherapy for inguinal lymph node metastases from melanoma

Although patients with inguinal or pelvic lymph node (LN) metastases from melanoma may develop regional recurrence after dissection, the role of adjuvant radiotherapy remains controversial.

The medical records of 40 patients with inguinal and/or pelvic lymph node metastases from melanoma were reviewed retrospectively. Indications for adjuvant radiotherapy included the following nodal characteristics: extracapsular extension, LNs > or =3 cm in diameter, > or =4 involved LNs, and LN recurrence after prior nodal surgery. Thirty-seven of 40 patients underwent formal LN dissection. Three patients had only local excision of gross disease for recurrence after prior dissection. All patients received radiation to a median dose of 30 Gy at six Gy/fraction delivered twice weekly.

With a median follow-up time of 22.5 months, the 3-year actuarial distant metastasis-free and overall survival rates were 35% and 38%, respectively. The 3-year regional control rate was 74%. Univariate analyses of patient, tumor, and treatment characteristics failed to reveal any association with distant metastasis-free survival, overall survival, or regional control. Regional failures occurred in nine patients; seven of these were isolated dermal failures within the field of irradiation. Only two patients (5%) had LN basin recurrences; one of these patients also developed dermal recurrence. Fifteen of 40 patients developed lymphedema; in seven of these, lymphedema was present before initiation of radiation therapy.

Radiation may prevent recurrence of nodal disease in patients at high risk for regional failure, but in-field dermal recurrences may sometimes occur (8 of 40, 20%). Treatment-related lymphedema and death from metastatic melanoma were common.