Primary photodynamic therapy with verteporfin for pigmented posterior pole cT1a choroidal melanoma: a 3-year retrospective analysis

Combined photodynamic therapy and transpupillary thermotherapy for small choroidal melanoma

OBJECTIVE

The objective of this study was to determine whether combining verteporfin-based photodynamic therapy (PDT) and transpupillary thermotherapy (TTT) achieves adequate tumour control while maintaining visual acuity in individuals with small choroidal melanoma of amelanotic, melanotic, and variable pigmentation.

DESIGN

Individuals with posterior choroidal melanomas up to 3 mm in height underwent verteporfin-based PDT followed by immediate TTT. Further combined laser therapy was performed if a poor response was noted at 12 weeks or beyond. Tumours that demonstrated significant further growth were treated with brachytherapy or enucleation. A total of 37 eyes of 37 patients from the Terrace Eye Centre in Brisbane, Australia were studied. Average age of participants was 59.62 ± 12.45 years, and 17 of 37 participants were female (46%).

METHODS

This was a retrospective, noncomparative interventional study.

RESULTS

Seven of the 37 participants (19%) had recurrence of their tumour requiring further brachytherapy or enucleation. There was no statistically significant difference in visual acuity before and after treatment. There were no baseline characteristics that predicted treatment outcome. Ten individuals developed complications including epiretinal membrane (16%), scotoma (8%), cataract (3%), and macular edema (3%). No individuals experienced extraocular extension or progressed to metastatic disease. The mean follow-up time was 49 months.

CONCLUSION

Combined PDT and TTT achieved 81% tumour control in this study while preserving visual acuity. However, higher rates of local recurrence compared with brachytherapy warrant close follow-up to identify recurrences early.

Laser treatment for choroidal melanoma: Current concepts

Laser treatment has offered a relatively nonsurgical alternative for eye, life, and vision-sparing treatment of malignant melanoma of the choroid. Historically, the most commonly used forms of lasers were xenon-arc, argon laser, krypton laser, and the more recent transpupillary thermotherapy (TTT) and photodynamic therapy (PDT). Melanomas selected for laser treatment tend to be smaller and visibly accessible, which means these tumors are usually located in the posterior choroid. Laser treatments have been associated with both local tumor destruction and side effects. Unlike radiation therapy, laser treatment has been commonly associated with retinal traction, hemorrhage, chorioretinal neovascularization, and extra scleral tumor extension, as well as higher rates of local treatment failure. In addition, however, laser-treatment has been successfully used to treat tumor-related retinal detachments, radiation retinopathy, and neovascular glaucoma. We review the world's experience of ophthalmic laser treatment for choroidal melanoma, offer safety and efficacy guidelines, as well as a comparison of laser treatment to radiation therapy outcomes.

Photodynamic therapy of primary and recurrent forms of weakly pigment choroidal melanoma

Treatment of poorly-pigmented tumors of small sizes can be carried out using photodynamic therapy (PDT). The material for the analysis was data on 112 patients. We used data from the Belarusian Cancer Registry, medical records of patients with clinically diagnosed choroid melanoma (C69.3 according to ICD-10) for the period 2013–2021. The size and level of blood flow in the tumors were assessed using an ultrasound machine with a doppler attachment. PDT was carried out using a «UPL PDT» semiconductor laser (Lemt, Republic of Belarus, λ=661 nm) with a light spot diameter of 1 to 3 mm for 60 s per field with a light dose of 50 J/cm2. The entire surface of the tumor was exposed to the action, with the fields “tiled”, from the periphery to the top of the tumor, with overlapping fields. Tumor pigmentation was assessed visually. To evaluate the treatment outcome, the general group of patients was divided into three subgroups according to thickness and basal diameter. Group I – 40 (35.7%) patients, with an average tumor thickness of 1.4±0.2 mm, basal diameter – 5.8±1.5 mm. II – 51 (45.5%) patients, with an average tumor thickness of 2.3 ± 0.3 mm, basal diameter – 7.9 ± 1.5 mm. III – 21 (18.8%) patients. The mean value of the tumor thickness was 3.8±0.4 mm, the basal diameter was 9.8±1.4 mm. After PDT in the general group (n=112), 29 (25.9%) patients had complete tumor resorption, and 83 (74.1%) patients had stabilization. The eyeball was saved in 107 (95.5%) patients. Continued growth and relapse were recorded in 34 patients: 25 (22.3%) and 9 (8.0%), respectively. In 29 (85.3%) patients, the eyeball was preserved after treatment of relapse and continued growth. 5 (4.5%) enucleations were performed. Adjusted one-year cumulative survival was 100%, 3-year and 5-year 95.8±2.4%, 93.7±3.1%, respectively

Photodynamic therapy for choroidal melanoma: What is the response rate?

To determine the response rate of choroidal melanoma following primary photodynamic therapy, we conducted a meta-analysis of published studies. A total of 7 studies reporting photodynamic therapy as primary treatment of choroidal melanoma in 162 patients with a mean tumor height of 2.8 mm (1.4 to 4.2) were identified. Forty-six percent of tumors were amelanotic, 48% were fully pigmented, and 6% had partial pigmentation. The photodynamic therapy parameters in all studies included 10-minute intravenous infusion of verteporfin (6 mg/m²), but varied in number of sessions (1 to 3), fluence (1× to 19×), and number of spots (single or multiple). The response was defined as tumor regression (partial or total) or lack of growth after initial treatment. The response to photodynamic therapy was predominantly observed as regression (126 [78%]). Overall response rate was 80% (mean) with a wide range among studies (58%-100%) over a period of 50 months (mean) with variable follow-up (range, 1-156 months). None of the studies reported progression- or recurrence-free survival; however, the recurrence rate was not related to the follow-up duration. Favorable prognostic factors were smaller size and lack of pigmentation. The overall response rate of 80% suggests that photodynamic therapy may be an effective primary treatment for small choroidal melanoma, especially in cases without pigmentation. Artifacts in study design (inclusion criteria and outcome measure) may have contributed to the variable observed response rate. Further studies with uniform inclusion criteria, standardized treatment parameters, well-defined outcome measures, and long follow-up are needed.

Long-term Outcomes of Small Pigmented Choroidal Melanoma Treated with Primary Photodynamic Therapy

PURPOSE

To report the long-term outcomes of patients with small, pigmented, posteriorly located choroidal melanoma undergoing primary treatment using photodynamic therapy (PDT) with verteporfin at the London Ocular Oncology Service.

DESIGN

Retrospective, interventional, consecutive case series.

PARTICIPANTS

All patients undergoing primary treatment using PDT with verteporfin from April 2014 to December 2015 and followed until December 2019.

METHODS

This is a long-term follow-up study of the same cohort of patients previously reported by our group in 2017 and 2018.

MAIN OUTCOME MEASURES

Local tumor control, visual outcomes, and metastasis-free survival.

RESULTS

Twenty-six patients were included with a mean (± standard deviation) age and tumor thickness of 62 ± 14 years and 1.3 ± 0.5 mm, respectively. Tumors were posteriorly located (mean distance to optic nerve and fovea = 2.0 ± 2.2 mm and 1.6 ± 1.5 mm, respectively), and the majority were fully pigmented (73%). Overall, patients were followed for a median (interquartile range [IQR], range) of 49.5 (15.3, 7.0-66.0) months from first PDT to last follow-up. Over the course of this study, 14 of 26 (54%) have developed a local recurrence at a median of 20.0 months (20.5, 4.7-60.9 months). The most common pattern of recurrence was an isolated increase in basal dimensions (9/14; 64%). Median (IQR) final logarithm of the minimum angle of resolution visual acuity of the whole cohort was 0.2 (0.5). The only statistically significant difference in baseline and outcome characteristics between treatment failures and nonfailures was the distance to the fovea (median [IQR], 0.5 [1.3] vs. 2.5 [2.8]; P = 0.002) and final logarithm of the minimum angle of resolution visual acuity (median [IQR], 0.50 [0.80] vs. 0.00 [0.14]; P = 0.002), respectively.

CONCLUSIONS

Although treatment of small pigmented posterior choroidal melanoma with PDT effectively preserves visual acuity, 5-year treatment-success calculated by Kaplan-Meier analysis was only 38.4%. Recurrences after PDT tend to occur along the tumor edges, often with minimal increase in thickness. Given the substantial risk of treatment failure, primary PDT with vertepofrin is recommended in exceptional cases of choroidal melanoma, for which other treatments with greater tumor control are not a feasible option.

Primary photodynamic therapy for small amelanotic choroidal melanomas: consecutive case series of 69 patients with at least 24-month follow-up

AIMS

To investigate the success and recurrence rates and visual outcomes in a large case series of amelanotic posterior choroidal melanomas treated by means of primary photodynamic therapy (PDT) with verteporfin.

METHODS

Retrospective case series from a single specialist ocular oncology centre. All patients had a clinical diagnosis of choroidal melanoma and were selected for PDT based on tumour characteristics. Included patients had at least 24 months of follow-up from initiation of treatment and all but one had not received treatment prior to PDT.

RESULTS

69 patients were included. Mean tumour thickness was 1.9 mm (range 0.5-4.4), while the mean basal diameter was 6.9 mm (range 2.4-11.0). Included lesions were stage cT1a (n=66) or cT2a (n=3). The mean duration of follow-up from treatment initiation was 57 months (range 24-116 months). Seven lesions (10%) failed to respond to PDT. 10 patients (16%) experienced recurrence during follow-up. Overall success rate in this series was 75% (n=52). 83% of successfully treated patients (n=43) maintained or gained vision by final follow-up. Visual outcomes were significantly better in those patients who received PDT therapy alone in comparison to those who needed other treatments for their melanoma (Fisher's exact test, p=0.004). Unfortunately, one patient (1.4%) in the series developed systemic metastases and died.

CONCLUSION

Selected amelanotic posterior uveal melanomas may be successfully treated with PDT with retention of good vision in the majority of cases, maintained with a mean of 57 months (minimum of 24 months) of follow-up.

Uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. UMs are usually initiated by a mutation in GNAQ or GNA11, unlike cutaneous melanomas, which usually harbour a BRAF or NRAS mutation. The annual incidence in Europe and the USA is ~6 per million population per year. Risk factors include fair skin, light-coloured eyes, congenital ocular melanocytosis, ocular melanocytoma and the BAP1-tumour predisposition syndrome. Ocular treatment aims at preserving the eye and useful vision and, if possible, preventing metastases. Enucleation has largely been superseded by various forms of radiotherapy, phototherapy and local tumour resection, often administered in combination. Ocular outcomes are best with small tumours not extending close to the optic disc and/or fovea. Almost 50% of patients develop metastatic disease, which usually involves the liver, and is usually fatal within 1 year. Although UM metastases are less responsive than cutaneous melanoma to chemotherapy or immune checkpoint inhibitors, encouraging results have been reported with partial hepatectomy for solitary metastases, with percutaneous hepatic perfusion with melphalan or with tebentafusp. Better insight into tumour immunology and metabolism may lead to new treatments.