Long-term results of primary transpupillary thermal therapy for the treatment of choroidal malignant melanoma

Background/aims: This is a long-term follow-up report investigating primary transpupillary thermal therapy (TTT) for choroidal melanoma. Methods: Retrospective case series of 135 patients harbouring choroidal melanoma treated with primary TTT. Patient demographics, tumour characteristics, treatment responses and complications, visual acuity outcomes and mortality data were captured and reported. A statistical analysis was performed for predictors of treatment failure. Results: Successful tumour regression was achieved in 76% of patients. Of the 32 patients who failed, 12 had enucleation, and 20 had irradiation. Metastatic disease has occurred in three patients, and two patients have died (3/135, or 2%). Multivariate analysis determined that tumour diameter, tumour thickness greater than 3 mm and tumours exhibiting high-risk characteristics were significant predictors of failure. Patient age, gender, number of treatments and proximity of the tumour to the disc or fovea were not predictive of failure. Kaplan-Meier cumulative probability predicted a 19% 5-year treatment failure and 33% 10-year treatment failure. Treatment failure occurred as late as 99 months. Final visual acuity was 20/40 or better in 50% of patients; 32% had a final visual acuity of 20/200 or worse. Thirty-two per cent of patients developed one or more complications as a result of the TTT, the most concerning of which was intra- or extrascleral extension of tumour (occurring in 11 patients). Conclusions: Though not as successful as radiation therapy, TTT successfully induced regression in 76% of patients. TTT may still have a role in our treatment paradigm but should probably be reserved for specific cases, such as monocular patients with tumours near critical visual structures, surgically unstable patients or patients with advanced diabetic retinopathy. All patients considering TTT as monotherapy for choroidal melanoma must be selected, counselled and followed appropriately.