Nodal radiation therapy for metastatic melanoma

The aim of this retrospective study was to review our experience of radiation therapy to regional nodes in patients with proven nodal metastases, with respect to regional control, late toxicity, and overall survival.

All patients with a histological diagnosis of malignant melanoma, with involvement of the regional nodes but without distant metastases, who commenced nodal irradiation between January 1985 and July 1995 at Peter MacCallum Cancer Institute were studied. The study population of 113 patients was divided into two categories: those with no residual macroscopic disease following nodal surgery (adjuvant group, 42 patients) and those who had no surgery (8) or had macroscopic residual disease following nodal surgery (63) (palliative group, 71 patients).

In the adjuvant group at 5 years following commencement of nodal irradiation 26% were estimated to be failure-free. Of the 74% who had experienced treatment failure by 5 years, an estimated 20% failed first with nodal relapse, 52% with distant metastases, and 2% with both nodal relapse and distant metastases. The estimated 5-year overall survival for this group was 33%. In the palliative group 16 patients (23%) had an objective complete response. Altogether 48 patients (68%) had a symptomatic response. At 5 years the overall survival in this group was 8% and an estimated 4% were failure-free. Of the 96% who had failed by 5 years, 68% failed first in the regional nodes, 25% had distant metastases as the first failure, and 3% had both nodal relapse and distant metastases.

We recommend adjuvant postoperative radiation therapy for patients with proven nodal metastases and high risk of regional recurrence (multiple nodes, extracapsular extension, or recurrent nodal disease) in addition to adjuvant interferon.