Adjuvant indocyanine green in transpupillary thermotherapy for choroidal melanoma
Patrick De Potter1, Jacques Jamart
1Ocular Oncology Unit, Cliniques Universitaires St.-Luc, Université Catholique de Louvain, 10 avenue Hippocrate, 1200 Brussels, Belgium. depotter@ofta.ucl.ac.be
Objective:
To determine the effect of indocyanine green (ICG) injection on the regression pattern of choroidal melanomas treated with transpupillary thermotherapy (TTT).
Design:
Prospective, randomized, controlled study.
Participants:
Of the 60 patients with posterior pole choroidal melanoma, 30 were managed with TTT alone (control group), and 30 received adjuvant ICG before TTT.
Methods:
Subjects with selected choroidal melanoma were treated with TTT by using infrared radiation delivered from the diode laser. For those patients randomized to ICG administration, the start of TTT was based on the onset of fluorescence documented on ICG angiography.
Main Outcome Measures:
Final tumor thickness (1.5 mm) and temporal tumor thickness regression.
Results:
The mean initial tumor basal diameter was 7.7 mm, and tumor thickness was 2.9 mm in the TTT treatment group. Tumor dimensions were initially 7.8 mm in the base and 3.1 mm in thickness in the TTT + ICG treatment group. During a median follow-up of 30 months (range, 6-49 months), the mean tumor thickness gradually decreased to 2.3 mm at month 3 and to 1.9 mm at month 6 after the initial session in the TTT treatment group and to 2.5 mm at month 3 and 2.2 mm at month 6 in the TTT + ICG treatment group. In the TTT treatment group, the reduction of tumor thickness was 19% at month 3 and 30% at month 6. In the TTT + ICG treatment group, the reduction of tumor thickness was 22% at month 3 and 31% at month 6. There were 12 tumors (40%) in the TTT treatment group and 15 (50%) in the TTT + ICG treatment group that measured 1.5 mm in thickness, with a flat ophthalmoscopic appearance. Tumor control was achieved in 55 tumors (92%). Two patients developed tumor recurrence in the TTT treatment group, and three developed recurrence in the TTT + ICG treatment group. A smaller initial tumor thickness, more TTT sessions, and a tumor location other than temporal were statistically predictive of a final tumor thickness of 1.5 mm. There was no apparent effect of ICG administration before TTT on the final tumor thickness and temporal tumor thickness regression.
Conclusions:
Despite the efficacy of TTT in the management of selected choroidal melanomas, adjuvant ICG administration before each TTT session does not seem to be beneficial in their regression pattern. Further research in vivo with a larger sample of patients and longer follow-up will be necessary to determine the role of ICG in TTT for choroidal melanomas.
