Transpupillary Thermotherapy as Primary Treatment for Small Choroidal Melanomas

Abstract

To report the short-term follow-up results of eyes containing small choroidal melanomas that were treated with transpupillary thermotherapy. Methods: Twenty eyes with suspected small choroidal melanomas were treated with transpupillary thermotherapy using infrared light delivered from the diode laser. Results: The age of the patients ranged from 26 to 82 years. In 14 patients, there was documented growth of the melanoma before transpupillary thermotherapy. The tumor thickness ranged from less than 1.0 to 3.2 mm. Seven tumors were treated more than once. Follow-up ranged from 6 months to more than 3 years. Following treatment, the tumor thickness decreased in all cases, usually within 2 months. Progressive atrophy of tumor mass and loss of pigmentation within the tumor continued beyond 1 year of follow-up in some eyes. Complications included field defects, vascular changes, and macular abnormalities. Conclusions: Transpupillary thermotherapy of small choroidal melanomas is usually followed by early tumor shrinkage but is complicated by dense scotomas, nerve fiber bundle defects, and, occasionally, macular abnormalities. The short-term follow-up results suggest that transpupillary thermotherapy may arrest the growth of selected small melanomas.

Choroidal Melanoma: Natural History and Management Options

“…29 Pigment in the tumor is responsible for absorbing energy and creating the heat that destroys the tumor cells, overlying pigment epithelium, and retina. The heat from TTT leaves a light gray uptake over the tumor at the end of each 60-second treatment 51 that is sharply demarcated from normal choroid around the tumor even though both areas are included in the treatment zone 53,54 (Fig 3). It is important to note that the appearance of a white coagulation lesion early during the application of TTT increases the amount of laser light reflected and thus decreases the amount transmitted into the tumor.…”

“…55 However,TTT still leads to immediate profound visual field defects corresponding to the treated areas secondary to photoreceptor and nerve fiber layer destruction. 54 Since TTT destroys nerve fibers within this area, the defects will extend from this area to the area innervated by the fibers passing through the treated area. Moreover, the defect may be markedly larger than the treated area if the tumor is located very close to the optic disc.…”

Falha a longo prazo no tratamento do melanoma de coróide com termoterapia transpupilar

“…Early studies on TTT reported satisfactory and replicable results, but they had a short follow-up time (1)(2)(3)(4) . More recently, different publications have supported a more cautious approach, and there is disagreement regarding the method's results and complications.…”

“…In this technique, a laser beam -infrared radiation -is applied through the pupil to raise the temperature and destroy tumour tissue through cytotoxicity (1,3) . The method can produce necrosis up to a maximum depth of 3.9 mm without affecting structures outside the treatment field.…”

“…The method can produce necrosis up to a maximum depth of 3.9 mm without affecting structures outside the treatment field. Its advantages include a limited field of action, the fact that it does not need to be conducted in an operating theatre, the preservation of the organ and its function (patients with extra-macular foci may retain good visual acuity), and good survival rates (1)(2)(3)(4) .…”