Transpupillary thermotherapy in the treatment of choroid melanoma

Objective: To report the results of primary transpupillary thermotherapy (TTT) for selected posterior pole choroidal melanomas.

Methods: Prospective non randomized study including 34 patients with choroidal melanoma treated with TTT using near-infrared radiation (810 nm) delivered from the diode laser. All treated tumors had either documented growth or clinical risk factors for future growth and/or metastasis. The treatment was delivered using a specially modified infrared diode laser through a slit lamp adaptor. A contact lens was placed on the cornea to view the fundus and focus the laser beam. Treatment was initiated using a 60-second exposure and a low energy level at 300 mW with a 3.0 mm beam width. The energy was raised stepwise by 50 to 100 mW until the surface of the tumor develop a light grayish discoloration. The TTT sessions were delivered at 3-month intervals.

Results: Among these 34 patients with choroidal melanoma, 29 patients presented with primary choroidal melanoma. Five tumors (15%) were late recurrences after conservative treatment. The mean initial tumor basal diameter was 7.2 mm and tumor thickness was 2.9 mm. Seventeen tumors (50%) touched the optic disc and 10 (29%) were under the fovea. After a mean of three treatment sessions and 20 months of follow-up, the mean tumor thickness gradually decreased to 2.3 mm at month 3 and 2.0 mm at month 6 after the initial TTT. The percent reduction of tumor thickness was 20% at month 3 and 29% at month 6. The mean final thickness was 1.7 mm. Treatment was successful in 33 patients (97%). Tumor regrowth was documented in one patient (3%) and required plaque radiotherapy. After treatment, visual acuity was the same or better than the pretreatment visual acuity in 21 eyes (62%) and worse in 13 eyes (38%). Intraocular complications included retinal traction in 12 eyes (34%) and vascular occlusion in 3 eyes (9%).

Conclusions: This series confirms the efficacy of transpupillary thermotherapy in the management of selected posterior pole choroidal melanomas. Longer follow-up is still required to assess late local recurrence and the impact on metastatic disease.