Episcleral iridium-192 wire therapy for choroidal melanomas

Comparison of Iodide-125 and Ruthenium-106 Brachytherapy in the Treatment of Choroidal Melanomas

Background

To compare iodine-125 (¹²⁵I) with ruthenium-106 (¹⁰⁶Ru) episcleral plaque radiation therapy in terms of the effectiveness and non-inferiority for choroidal melanoma treatment.

Objective

To report the non-inferiority of new made iodine-125 (¹²⁵I) compared with ruthenium-106 (¹⁰⁶Ru) episcleral plaque radiation.

Patients and Methods

A retrospective, non-randomized comparative case series. In this series the patients treated with ¹²⁵I and ¹⁰⁶Ru episcleral plaques for choroidal melanoma between September 2013 and August 2017 at Farabi Hospital are compared. Local control of choroidal melanomas after ¹²⁵I and ¹⁰⁶Ru plaques implantation and vision changes are the main outcome measures.

Results

A total of 35 patients were identified (¹²⁵I = 15, ¹⁰⁶Ru = 20). No significant difference between two groups in visual acuity, diameter and thickness changes were observed after treatment. Multivariate linear regression (MLR) analysis showed that final diameter was only, independently and significantly, correlated with the pre-treatment diameter of the tumor (β = 0.59, 95% confidence interval [CI]: 0.29, 1.34, P = 0.003). The same MLR analysis for the final thickness and visual acuity, after adjusting for age and sex showed no significant difference between two groups. A single patient treated with ¹⁰⁶Ru had local tumor recurrence with no one in the ¹²⁵I group. No statistical difference in the rate of ocular complications was observed.

Conclusion

The treatment with our ¹²⁵I plaques is as effective as ¹⁰⁶Ru plaques in controlling choroidal melanoma tumor and preserving the vision during the two and half year of follow-up. The complication rates are alike. It means that the effectiveness of ¹²⁵I is not only comparable to ¹⁰⁶Ru but also superior when the outcome of the interest is the thickness of the tumors.

The American Brachytherapy Society recommendations for brachytherapy of uveal melanomas

PURPOSE

This article presents the American Brachytherapy Society (ABS) guidelines for the use of brachytherapy for patients with choroidal melanomas.

METHODS

Members of the ABS with expertise in choroidal melanoma formulated brachytherapy guidelines based upon their clinical experience and a review of the literature. The Board of Directors of the ABS approved the final report.

RESULTS

Episcleral plaque brachytherapy is a complex procedure and should only be undertaken in specialized medical centers with expertise in this sophisticated treatment program. Recommendations were made for patient selection, techniques, dose rates, and dosages. Most patients with very small uveal melanomas (<2.5 mm height and <10 mm in largest basal dimension) should be observed for tumor growth before treatment. Patients with a clinical diagnosis of medium-sized choroidal melanoma (between 2.5 and 10 mm in height and <16 mm basal diameter) are candidates for episcleral plaques if the patient is otherwise healthy and without metastatic disease. A histopathologic verification is not required. Small melanomas may be candidates if there is documented growth; some patients with large melanomas (>10 mm height or >16 mm basal diameter) may also be candidates. Patients with large tumors or with tumors at peripapillary and macular locations have a poorer visual outcome and lower local control that must be taken into account in the patient decision-making process. Patients with gross extrascleral extension, ring melanoma, and tumor involvement of more than half of the ciliary body are not suitable for plaque therapy. For plaque fabrication, the ophthalmologist must provide the tumor size (including basal diameters and tumor height) and a detailed fundus diagram. The ABS recommends a minimum tumor (125)I dose of 85 Gy at a dose rate of 0.60-1.05 Gy/h using AAPM TG-43 formalism for the calculation of dose. NRC or state licensing guidelines regarding procedures for handling of radioisotopes must be followed.

CONCLUSIONS

Brachytherapy represents an effective means of treating patients with choroidal melanomas. Guidelines are established for the use of brachytherapy in the treatment of choroidal melanomas. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose reporting policies. These guidelines will be modified as further clinical results become available.

Internal resection of posterior uveal melanomas

AIMS

To evaluate the safety and efficacy of internal resection in the treatment of malignant melanoma of the choroid.

METHODS

32 consecutive patients with histopathologically proved malignant choroidal melanomas were treated with internal resection. 29 of the 32 (90.6%) tumours were within 2 disc diameters of the optic nerve or fovea. The surgery was performed at two university centres by one of the authors. Follow up was between 1 and 85 months (mean 40.1 months).

RESULTS

Three patients developed distant metastases and died of malignant melanoma (metastatic and mortality rate 9.4%). In one case, distant metastases developed in association with an intraocular recurrence. There have been no other intraocular recurrences. The most common postoperative complication was vitreous haemorrhage, which occurred in 12 patients (37.5%); cataract occurred in eight eyes; and three patients developed retinal detachment postoperatively. Three of the operated eyes have been enucleated (9.4%); a total of four (12.5%) have lost light perception. 10 patients (31.2%) had visual acuities of 6/60 or better and 18 of 32 (56.3%) were between 6/120 and light perception.

CONCLUSION

These data suggest that the internal resection of posterior uveal melanomas is a reasonable globe saving management option. This treatment modality is particularly well suited to elevated tumours in close proximity to the optic nerve or fovea.

Treatment of retinoblastoma vitreous base seeding

OBJECTIVE

The purpose of the study is to describe results of a new treatment for retinoblastoma vitreous base seeding.

DESIGN

The study design was a retrospective review of patients treated at an ocular oncology referral center.

PARTICIPANTS

Five eyes of five patients with vitreous base seeding that occurred after previous external beam radiation therapy were treated between October 1987 and December 1994.

INTERVENTION

A customized plaque made from iridium-192/platinum wire was placed to deliver 4000 cGy to the tumor apex along its entire length and systemic chemotherapy (consisting of carboplatin, vincristine, and etoposide) was given.

MAIN OUTCOME MEASURES

Eye preservation and tumor control were measured.

RESULTS

Vitreous base seeding was controlled completely and the eye preserved in four of the five treated eyes with an average follow-up of 26.2 months.

CONCLUSIONS

The combination of a customized iridium-192 plaque and systemic chemotherapy is an effective means of treating vitreous base seeding of retinoblastoma.