Plaque brachytherapy in iris and iridociliary melanoma: a systematic review of efficacy and complications

Abstract

Purpose To evaluate the efficacy and vision-threatening complication rate of plaque brachytherapy with iodine-125 ( 125 I), palladium-103 ( 103 Pd), and ruthenium-106 ( 106 Ru) for treatment of iris and iridociliary melanoma. Material and methods A literature review was done based on results yielded from searching PubMed, Embase, and Cochrane database, using following key words: iris melanoma, iridociliary melanoma, brachytherapy, iodine-125 brachytherapy, palladium-103 brachytherapy, and ruthenium-106 brachytherapy. Initially, relationships between mean radiation dose to apex and local recurrence and complication rate were analyzed, and then, a comparison was performed between 125 I, 103 Pd, and 106 Ru studies. Results Twelve retrospective and prospective studies were selected, with 491 patients treated primarily with plaque brachytherapy. The range of radiation dose to tumor apex were from 84 to 151.5 Gy. Ranges of mean and median of follow-up time were from 27 to 96 months. Local recurrence rate following brachytherapy ranged from 0 to 8%. A decrease in the average study dose was not associated with an increased local recurrence or metastasis rate ( p = 0.373 and 0.195, respectively); however, an increase in radiation dose was associated with higher radiation-related cataract and glaucoma ( p < 0.05). The rate of post-treatment glaucoma was higher in studies with 125 I plaque brachytherapy ( p = 0.004). Conclusions For brachytherapy of iris and iridociliary melanoma, in a range of 84 to 150 Gy, an increase in radiation dose may increase the risk of complications, while the tumor control rate does not change.

Intraocular Lens and Lens Capsule Spread of Iridociliary Melanoma: Clinical and Histopathologic Features of 2 Cases

“…Tumor cells and pigment-laden macrophages may obstruct the trabecular meshwork, leading to secondary open-angle glaucoma [10], which was the mechanism in our cases. IOP elevation is identified as an aggressive feature of iris melanoma [7], but it is also a known complication after plaque brachytherapy [11]. For our second case, the presence of suspicious membrane-like pigmentation on the surface of the IOL and increased pigmentation of the inferior angle supported the diagnosis of recurrent melanoma.…”

Ruthenium brachytherapy for iris melanoma

“…Of note, due to low incidence of iris and iridociliary melanoma, there are few articles on this subject in the literature, and most reported groups are not homogenous in terms of iridocorneal angle involvement. The median group size was 27 patients (range, 11-144 patients) [10]. The concept of irradiating iris tumor with a radioactive plaque is not new, it dates back to 1994 when Shields et al presented a novel treatment method with 125 I plaque for non-resectable iris melanoma adopted from posterior uveal melanoma management [13].…”

“…Since then, different types of plaques and radionuclides were used for irradi-ating iris tumors, showing satisfying outcomes [6,[11][12][13][14][15][16][17][18]. However, in a systematic review on plaque brachytherapy for iris and iridociliary melanoma by Karimi et al, there were only 12 papers included [10]. Different authors described the use of 125 I, 103 Pd, and 106 Ru plaques in the management of iris melanomas [6,11,15,[17][18][19][20][21].…”

“…Ruthenium-106 ( 106 Ru) plaque brachytherapy is a method of conservative therapy for iridociliary melanoma among other treatment options, such as local excision (iridocyclectomy), iodine-125 ( 125 I), palladium-103 ( 103 Pd) plaque brachytherapy, and proton beam radiation therapy (PBRT) [5,6,[10][11][12]. Irradiation of iris tumor is considered a treatment of choice for lesions involving an angle with more than 2-clock hours, therefore non-resectable.…”

Clinical Outcomes after Surgical Resection Combined with Brachytherapy for Uveal Melanomas

“…85% of ocular melanomas originate in the uvea, with the most common location being the choroid (80% of the total), followed by the ciliary body (12%) and iris (8%). Brachytherapy is the most commonly used form of radiotherapy for uveal melanoma, and with the use of I-125 and Ru-106 isotopes, it achieves a local control rate in the range of 88–98% at five years [ 1 , 15 ]. Despite its results, radiation retinopathy is the most common ocular side effect after brachytherapy for uveal melanoma [ 10 ].…”