A prospective phase II study of adjuvant postoperative radiation therapy following nodal surgery in malignant melanoma-Trans Tasman Radiation Oncology Group (TROG) Study 96.06.

BACKGROUND

The role of adjuvant postoperative therapy after resection of localised malignant melanoma involving regional lymph nodes remains controversial. There are no randomised trials that confirm that postoperative radiation conveys a benefit in terms of regional control or survival.

METHODS

Two hundred and thirty-four patients with melanoma involving lymph nodes were registered on a prospective study to evaluate the effect of postoperative radiation therapy. The regimen consisted of 48Gy in 20 fractions to the nodal basin using recommended treatment guidelines for each of the major node sites. The primary endpoints were regional in-field relapse and late toxicity. Secondary endpoints were adjacent relapse, distant relapse, overall survival, progression-free survival and time to in-field progression.

RESULTS

Adjuvant radiation therapy was well tolerated by all of the patients. As the first site of relapse, regional in-field relapses occurred in 16/234 patients (6.8%). The overall survival was 36% at 5 years. The progression-free survival and regional control rates were 27% and 91%, respectively, at 5 years. Patients with more than 2 nodes involved had a significantly worse outcome in terms of distant relapse, overall and progression-free survival.

CONCLUSION

We believe that adjuvant radiation therapy following nodal surgery could offer a possible benefit in terms of regional control. These results require confirmation in a randomised trial.