Photodynamic therapy as initial treatment for small choroidal melanomas

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

Small High-Risk Uveal Melanomas Have a Lower Mortality Rate

Simple Summary

The current paradigm concerning metastatic spread in uveal melanoma is that the critical point for dissemination occurs prior to presentation and that treatment of the primary tumor does not change outcome. However, we show that patients with small uveal melanomas with genetic characteristics typical for high risk for metastatic disease have a lower mortality rate from metastatic disease, if treated earlier. Our data demonstrate that such small melanomas are potentially lethal (like larger tumors), but that there is a window of opportunity to prevent life-threatening metastatic spread if actively treated, rather than being monitored, as is often done currently.

Abstract

Our aim was to determine whether size impacts on the difference in metastatic mortality of genetically high-risk (monosomy 3) uveal melanomas (UM). We undertook a retrospective analysis of data from a patient cohort with genetically characterized UM. All patients treated for UM in the Liverpool Ocular Oncology Centre between 2007 and 2014, who had a prognostic genetic tumor analysis. Patients were subdivided into those with small (≤2.5 mm thickness) and large (>2.5 mm thickness) tumors. Survival analyses were performed using Gray rank statistics to calculate absolute probabilities of dying as a result of metastatic UM. The 5-year absolute risk of metastatic mortality of those with small monosomy 3 UM was significantly lower (23%) compared to the larger tumor group (50%) (p = 0.003). Small disomy 3 UM also had a lower absolute risk of metastatic mortality (0.8%) than large disomy 3 UM (6.4%) (p = 0.007). Hazard rates showed similar differences even with lead time bias correction estimates. We therefore conclude that earlier treatment of all small UM, particularly monosomy 3 UM, reduces the risk of metastatic disease and death. Our results would support molecular studies of even small UM, rather than ‘watch-and-wait strategies’.

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.

Blue light-triggered optogenetic system for treating uveal melanoma

Uveal melanoma is the most common intraocular primary malignancy in adults and has been considered a fatal disease for decades. Optogenetics is an emerging technique that can control the activation of signaling components via irradiation with visible light. The clinical translation of optogenetics has been limited because of the need for surgical implantation of electrodes and relatively shallow tissue penetration. As visible light easily penetrates the eyes, we hypothesized that an optogenetics approach can be an effective treatment of uveal melanoma without surgery. In this study, we evaluated the feasibility of this strategy by using a genetically encoded optogenetic system based on reversible blue light-induced binding pairs between Fas-CIB1-EGFP and CRY2-mCherry-FADD. Subretinal injection of B16 cells was performed to create a uveal melanoma model. Plasmids pairs were co-transfected into B16 cells. We found that blue light irradiation dynamically controlled the translocation of FADD to Fas on the plasma membrane and induced the apoptosis of B16 cells transfected with the optogenetic nanosystem in vitro. Moreover, the blue light-controlled optogenetic nanosystem suppressed the growth of uveal melanoma in vivo by inducing apoptosis. These results suggest that light-controlled optogenetic therapy can be used as a potential novel therapeutic strategy for uveal melanoma.

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

Aims

To investigate the outcomes of primary photodynamic therapy (PDT) for pigmented posterior pole cT1a choroidal melanoma.

Methods

Retrospective interventional consecutive case series of 26 patients (26 eyes) with pigmented posterior pole cT1a choroidal melanoma, who were treated with 3 sessions of PDT and followed-up thereafter.

Results

Included were 11 males and 15 females that presented at a median age of 66 years (mean: 64) with transformed naevi (n=11) or suspicious lesions (n=15) with ≥3 risk factors for growth, with lipofuscin in all. In all cases, diagnosis was clinically based (no tissue biopsy). Tumour control was achieved in 16 (62%) patients in a median follow-up time of 29 months (mean: 27). Ten patients failed treatment by form of radial expansion, diagnosed in a median time of 13 months (mean: 12) from last treatment. By Kaplan-Meier analysis, success rate after 1, 2 and 3 years was 85%, 59% and 51%, respectively. On statistical analysis, number of suspicious features was found to be the only risk factor predicting failure (P=0.046). One patient developed macula-sparing branch retinal artery occlusion after treatment. Following PDT, subretinal fluid resolved in all cases and visual acuity significantly improved in all treatment-success cases (P=0.043). There were no cases of metastatic spread.

Conclusion

Primary PDT resulted in tumour regression of small, pigmented choroidal melanoma in 62% after a mean of 27 months. Treatment was more effective in tumours with three or less risk factors for growth, and resulted with fluid elimination and significant improvement in vision in treatment-success cases.