Regression patterns of choroidal melanoma: After palladium-103 (¹⁰³Pd) plaque brachytherapy

Abstract

Purpose:To describe the patterns of regression of choroidal melanoma after treatment with plaque brachytherapy.Methods:Retrospective interventional case series including 170 consecutive patients treated with 103Pd eye plaque radiation for choroidal melanoma. Outcome measures were changes in tumor thickness, surface characteristics, tumor vascularity, ultrasonography, fluorescein angiography, optical coherence tomography, and histopathology.Results:The mean initial tumor thickness was 3.9 mm (median 2.8 mm; range 2–11.3 mm) that decreased to 1.7 mm (median 1.2 mm; range 0–7.1 mm) after plaque brachytherapy. On imaging, tumors were pigmented in 51% (n = 86/170), amelanotic in 10% (n = 17/170), and variably pigmented in 39% (n = 67/170). Tumor pigmentation increased in 64% (n = 106/166), decreased in 18% (n = 30/166), and was unchanged in 18% (n = 30/166). Of the 120 that demonstrated intrinsic vascularity, 10% (n = 12/120) had decreased tumor-related vascularity and 90% (n = 108/120) showed complete resolution. Subretinal fluid was present in 34% (n = 58/170) of eyes at presentation. Of them, 15% (9; n = 9/58) had persistent SRF at last follow-up. On ultrasound imaging, 88% (n = 149/170) tumors presented with low to moderate internal reflectivity of which 61% (n = 91/149) showed increased reflectivity on regression. We noted a crescendo–decrescendo fluctuation in the presence of orange pigment lipofuscin along with complete resolution of drusenoid retinal pigment epithelial detachments. In the entire series of 170 patients, there was 0.5% (1) failure of local control, 2% (4) secondary enucleations, and 6% (10) patients developing metastasis.Conclusion:Findings related to choroidal melanoma regression after 103Pd plaque brachytherapy included decreased intrinsic tumor vascularity, decreased tumor-related subretinal fluid, increased pigmentation, specific changes in orange pigment lipofuscin and resolution of drusenoid retinal pigment epithelial detachments, as well as decreased tumor thickness with an increase in internal reflectivity on ultrasound.

Fundus Autofluorescence Imaging in Patients with Choroidal Melanoma

“…The regression patterns of choroidal melanoma after palladium-103 plaque brachytherapy have been described in a retrospective case series of 170 consecutive patients by Maheshwari and Finger, including a decrease in tumour thickness, an increase in tumour pigmentation, the diminution of tumour-related vascularity, resorption of subretinal fluid, and increasing internal reflectivity on ultrasonography post-therapy [ 89 ]. In addition, the presence of orange pigment was evaluated by means of FAF imaging pre- and post-therapy with a mean follow-up of 71 months (range 12–201 months).…”

Radiological and clinical findings in uveal melanoma treated by plaque interventional radiotherapy (brachytherapy): Visual atlas and literature review on response assessment

“…There are also other parameters, which should be taken into account when evaluating UM response, including decreased intrinsic tumor vascularity, decreased tumor-related sub-retinal fluid, increased pigmentation, specific changes in orange pigment lipofuscin, resolution of drusenoid retinal pigment in epithelial detachments, and increase in internal reflectivity on ultrasound. These parameters are especially important for situations, when a single-measure change in measured thickness does not comprehensively describe findings associated with regression, such as the case of iris melanomas [ 28 , 29 ].…”

Ipsilateral metastatic choroidal melanoma responds to systemic immunotherapy

“…The treated choroidal melanoma’s regression pattern was unremakable. 5 Her primary tumor reduced to 1.5 mm in apical height. Though her foveal radiation dose was 17.3 Gy, she developed early signs of radiation retinopathy (macular hemorrhages and cotton wool spots) 30 months after plaque brachytherapy.…”