Episcleral plaque thermoradiotherapy in patients with choroidal melanoma.
From 1988 to 1991, 21 patients with uveal melanoma were treated in a Phase I study with episcleral plaque radiotherapy (EPRT). This irradiation was combined with localized current field episcleral hyperthermia (LCFHT). Tumor stage was: T3 = 15 (71%) and T2 = 6 (29%). Follow-up ranged from 2 to 42 months (mean 9.2 months). EPRT was given using custom built I-125 gold plaques. Radiation doses to the tumor apex ranged from 13 to 123 Gy (mean dose 70.0 Gy) given at a mean dose rate of 55 cGy/hr. LCFHT was given with 500 KHz frequency for 45 min immediately before EPRT. The temperature was controlled on the scleral surface using four thermocouples. T mean ranged from 42.5 degrees C to 45 degrees C +/- 0.5 degrees C (mean 43.4 degrees C). The study patients showed rapid tumor necrosis. A 25% mean decrease of apical tumor dimension was noted, p = 0.0007. At least ambulatory vision (greater than 5/200) was maintained by 17/21 (81%) patients. Visual acuity was seen to improve greater than 6 months post-plaque therapy in 10 (48%) study patients. This was following an intermediate decrease in visual acuity. Severe complications, including large hemorrhagic retinal detachment and large vitreous hemorrhage, were seen in two (9.5%) of the early study patients. A mean scleral temperature reduction to less than or equal to 44 degrees C +/- 0.5 degrees C resulted in good treatment tolerance and a lack of serious complications in subsequently treated patients. A Phase II prospective randomized trial comparing LCFHT with 60 versus 80 Gy EPRT dose to the tumor apex is currently being activated for patients with choroidal melanoma.
Petrovich
Z
Z
Dept. of Radiation Oncology, University of Southern California, School of Medicine, Los Angeles 90033.
Astrahan
M A
MA
Luxton
G
G
Green
R
R
Langholz
B
B
Liggett
P
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002830:Choroid Neoplasms / Q000628:therapy*; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D008297:Male; D008545:Melanoma / Q000628:therapy*; D008875:Middle Aged