Tumor parameters predict the risk of side effects after ruthenium-106 plaque brachytherapy of uveal melanomas

Prognostic factors for surgical treatment of radiation-induced scleral necrosis after brachytherapy for uveal melanoma

PURPOSE

Radiation-induced scleral necrosis (RISN) is a less frequent complication of brachytherapy for uveal melanoma, and may require surgical treatment in selected cases. We aimed to identify the prognostic factors for RISN treatment.

METHODS

All patients with brachytherapy for uveal melanoma treated at our institution between 01/1999 and 12/2016 who developed RISN were followed until 02/2021. Various parameters were evaluated through univariable and multivariable Cox regression analysis. The surgical intervention due to RISN was the principal outcome event of this study.

RESULTS

Of 115 patients in the final cohort, 51 individuals (44%) underwent RISN treatment (conjunctival revision [n = 2], patching [n = 46] or enucleation [n = 3]) at median 1.80 months after RISN occurrence. Significant RISN characteristics were summarized into a novel RISN severity scale - Grade I: largest diameter ≤ 5 mm and no progression; Grade II: largest diameter > 5 mm or any progression during the follow-up; Grade III: presence of uveal prolapse; and Grade IV: leakage through open eyewall perforation. In the multivariable analysis, the RISN severity scale (aHR = 2.37 per grade increase, p = 0.01) and the time between brachytherapy and RISN occurrence (<15 months, aHR = 6.33, p < 0.0001) were independently associated with the study endpoint. The RISN severity scale showed high diagnostic accuracy for prediction of RISN treatment (AUC = 0.869).

CONCLUSIONS

In our series, about the half of RISN cases underwent surgical treatment. The presented novel severity scale for RISN might become a helpful tool for clinical management of individuals with RISN. We recommend external validation of the diagnostic accuracy of the presented scale.

Ocular Complications of Radiotherapy in Uveal Melanoma

Uveal melanoma is the most common primary malignant intraocular tumor in adults. Radiation therapy has replaced enucleation and is now the preferred treatment in most cases. Nonetheless, around 70% of patients develop radiation-related complications, some of which are vision-threatening. The objective of this review is to present the most important complications associated with radiotherapy in the treatment of uveal melanoma and their pathogenesis, incidence, risk factors, and available preventive and therapeutic measures. The most common complications are cataracts, with a reported incidence ranging from 4% to 69%, and radiation retinopathy, reported in 5-68% of cases. Radiation-related complications are responsible for approximately half of secondary enucleations, the leading cause being neovascular glaucoma. A poor visual outcome is mainly associated with the presence of radiation retinopathy and radiation optic neuropathy. Therapeutic options are available for the majority of complications with the notable exception of optic neuropathy. However, many studies report a final visual acuity of less than 20/200 in more than 60% of treated eyes. Reducing complication rates can be achieved by lowering the dose of radiation, with the use of eccentric, customized plaques and careful planning of the irradiation delivery in order to protect structures vital to vision and by associating radiation therapy with other methods with the aim of reducing tumor volume.

Incidence and Risk Factors for Secondary Glaucoma in Eyes with Uveal Melanoma

PURPOSE

To estimate incidence of and analyze risk factors for developing secondary glaucoma in eyes with uveal melanoma before and after diagnosis.

DESIGN

A cross-sectional, population-based cohort study.

PARTICIPANTS

Seven hundred eighty-one patients (median age, 64 years; range, 14-93) consecutively diagnosed with uveal melanoma from 1997 to 2012 in a national ocular oncology service, 708 (91%) of whom received ruthenium (50%) or iodine (50%) brachytherapy.

METHODS

Patient, tumor, treatment, and follow-up data were collected prospectively. Frequency and associations of melanoma-related glaucoma at tumor diagnosis were assessed. Incidence of developing secondary glaucoma after diagnosis was estimated by Kaplan-Meier analysis. Independent risk factors were modeled using Cox regression.

MAIN OUTCOME MEASURES

Melanoma-related glaucoma and related risk factors.

RESULTS

Forty-five patients (5.8%; 95% confidence interval [CI], 4.2-7.6) had tumor-related secondary glaucoma at diagnosis, 34 (76%) from a narrow-to-closed angle (25 had direct angle invasion) and 10 (22%) from anterior neovascularization. Synchronous metastases were common in patients with initial secondary glaucoma (11% vs. 1.2% with incident glaucoma, P = 0.005). Patients with secondary glaucoma were often male (58% vs. 48% without glaucoma; P = 0.010) and had larger tumors (median thickness, 9.1 vs. 4.0 mm; P < 0.001) involving the ciliary body (43% vs. 21%; P < 0.001) with retinal detachment (53% vs. 30%; P < 0.001). One hundred and sixty-eight patients 165 of which were treated with brachytherapy developed incident tumor- or treatment-related secondary glaucoma a median of 1.7 years (range, 0.1-13.6) after tumor diagnosis. Cumulative proportion of developing secondary glaucoma was 23% (95% CI, 20-27) at 5 years. The most common mechanism was neovascularization in 119 patients (71%; 95% CI, 63-78). By multivariable regression, initial retinal detachment 3 to 4 quadrants (hazard ratio [HR], 2.18; P < 0.001), initial intraocular pressure 17 mmHg or higher (HR, 1.64; P = 0.01), and tumor thickness predicted incident secondary glaucoma.

CONCLUSIONS

Secondary glaucoma at initial uveal melanoma diagnosis predicts high risk of synchronous metastases. Although anterior neovascularization is the most common mechanism for secondary glaucoma after diagnosis, other mechanisms such as angle narrowing and anterior chamber hemorrhage are not infrequent. Initial retinal detachment and intraocular pressure with tumor thickness could inform interim assessments of intraocular pressure and neovascularization.

Local tumor control and treatment related toxicity after plaque brachytherapy for uveal melanoma: A systematic review and a data pooled analysis

Uveal melanoma (UM) represents the most common primary intraocular tumor, and nowadays eye plaque brachytherapy (EPB) is the most frequently used visual acuity preservation treatment option for small to medium sized UMs. The excellent local tumor control (LTC) rate achieved by EPB may be associated with severe complications and adverse events. Several dosimetric and clinical risk factors for the development of EPB-related ocular morbidity can be identified. However, morbidity predictive models specifically developed for EPB are still scarce. PRISMA methodology was used for the present systematic review of articles indexed in PubMed in the last sixteen years on EPB treatment of UM which aims at determining the major factors affecting local tumor control and ocular morbidities. To our knowledge, for the first time in EPB field, local tumor control probability (TCP) and normal tissue complication probability (NTCP) modelling on pooled clinical outcomes were performed. The analyzed literature (103 studies including 21,263 UM patients) pointed out that Ru-106 EPB provided high local control outcomes while minimizing radiation induced complications. The use of treatment planning systems (TPS) was the most influencing factor for EPB outcomes such as metastasis occurrence, enucleation, and disease specific survival, irrespective of radioactive implant type. TCP and NTCP parameters were successfully extracted for 5-year LTC, cataract and optic neuropathy. In future studies, more consistent recordings of ocular morbidities along with accurate estimation of doses through routine use of TPS are needed to expand and improve the robustness of toxicity risk prediction in EPB.

Scleral necrosis after brachytherapy for uveal melanoma: Analysis of risk factors

BACKGROUND

Radiation-induced scleral necrosis (RISN) is a rare, but a serious complication of brachytherapy for uveal melanoma. We aimed at analysing the incidence, timing and risk factors associated with development of RISN in a large institutional series.

METHODS

All consecutive cases with brachytherapy for uveal melanoma treated by the Departments of Ophthalmology and Radiotherapy at University Hospital Essen between 1999 and 2016 were eligible. Development of RISN during the post-treatment follow-up was recorded. A 1:2 propensity score matched case-control study was performed for the evaluation of the prognostic value of different tumour- and treatment-associated parameters.

RESULTS

RISN was documented in 115 (2.9%) of 3960 patients with uveal melanoma included in the final analysis, and occurred at the mean 30.3 months (range: 1.26-226 months) after brachytherapy. In the whole cohort, younger age (p = 0.042), plaque type (p = 0.001) and ciliary body involvement (p < 0.0001) were independently associated with the RISN occurrence. In the case-control study, multivariable weighted proportional hazard analysis discovered the association of the following additional tumour- and treatment-associated characteristics with RISN: posterior tumour margin anterior to equatorial region (p = 0.0003), extraocular tumour extension (p = <0.0001), scleral contact dose (p = <0.0001), conjunctival dehiscence after therapy (p = 0.0001), disinsertion of the superior rectus muscle (p = 0.001) and the glaucoma medication (p = 0.014).

CONCLUSIONS

Our study confirms RISN as a rare complication, which might occur even years later after the brachytherapy for uveal melanoma. Alongside with scleral dose five other tumour and therapy related factors predict the risk of RISN after brachytherapy for uveal melanoma were established.

Iatrogenic Ocular Surface Diseases Occurring during and/or after Different Treatments for Ocular Tumours

Simple Summary

The ocular surface represents a finely regulated system that allows the protection of the eye. It can be affected by therapies used for the treatment of various intraocular tumours, particularly conjunctival cancers and uveal melanoma. In these conditions, treatments are chosen according to the characteristics of the lesion, and include a combination of selective surgery, anticancer eye drops, and/or radiotherapy delivered through different mechanisms. Possible side effects affecting the ocular surface range from transient dry eye or keratitis up to more severe complications such as corneal melting and perforation. These complications deserve careful evaluation for the risk of permanent sight-threatening sequelae. Physicians involved in the management of patients affected by ocular tumours should be aware of this risk in order to reach an early diagnosis and promptly set up an adequate treatment. The present review summarizes acute and chronic complications affecting the ocular surface following different therapies for the treatment of conjunctival cancers and uveal melanoma, and also reports clinical cases of representative patients who experienced these complications.

Abstract

The ocular surface represents a finely regulated system that allows the protection of the eye. It is particularly susceptible to different treatments for intraocular tumours, such as uveal melanoma and conjunctival cancers. Traditionally, the management of ocular tumours depends on the characteristics of the lesion, and is based on a combination of selective surgery, topical chemotherapy, and/or radiotherapy delivered through different mechanisms (e.g., charged-particle radiotherapy or brachytherapy). Possible complications involving the ocular surface range from transient dry eye disease or keratitis up to corneal melting and perforation, which in any case deserve careful evaluation for the risk of permanent sigh-threatening complications. Clinicians involved in the management of these patients must be aware of this risk, in order to reach an early diagnosis and promptly set up an adequate treatment. The present review of the literature will summarize acute and chronic complications affecting the ocular surface following different therapies for the treatment of ocular tumours.