Evaluation of Choroidal Melanoma Vascularization by Color Doppler Flow Imaging: An Option for Follow-Up Tumor Control Assessment after CyberKnife®?

Quantitative Biomarkers Derived from a Novel, Contrast-Free Ultrasound, High-Definition Microvessel Imaging for Differentiating Choroidal Tumors

Angiogenesis has an essential role in the de novo evolution of choroidal melanoma as well as choroidal nevus transformation into melanoma. Differentiating early-stage melanoma from nevus is of high clinical importance; thus, imaging techniques that provide objective information regarding tumor microvasculature structures could aid accurate early detection. Herein, we investigated the feasibility of quantitative high-definition microvessel imaging (qHDMI) for differentiation of choroidal tumors in humans. This new ultrasound-based technique encompasses a series of morphological filtering and vessel enhancement techniques, enabling the visualization of tumor microvessels as small as 150 microns and extracting vessel morphological features as new tumor biomarkers. Distributional differences between the malignant melanomas and benign nevi were tested on 37 patients with choroidal tumors using a non-parametric Wilcoxon rank-sum test, and statistical significance was declared for biomarkers with p-values < 0.05. The ocular oncology diagnosis was choroidal melanoma (malignant) in 21 and choroidal nevus (benign) in 15 patients. The mean thickness of benign and malignant masses was 1.70 ± 0.40 mm and 3.81 ± 2.63 mm, respectively. Six HDMI biomarkers, including number of vessel segments (p = 0.003), number of branch points (p = 0.003), vessel density (p = 0.03), maximum tortuosity (p = 0.001), microvessel fractal dimension (p = 0.002), and maximum diameter (p = 0.003) exhibited significant distributional differences between the two groups. Contrast-free HDMI provided noninvasive imaging and quantification of microvessels of choroidal tumors. The results of this pilot study indicate the potential use of qHDMI as a complementary tool for characterization of small ocular tumors and early detection of choroidal melanoma.

Long term outcome of adjuvant photodynamic therapy after cyberknife radiotherapy for choroidal melanoma

PURPOSE

To report the outcome of photodynamic therapy (PDT) for choroidal melanoma as adjuvant treatment with CyberKnife radiotherapy.

DESIGN

Retrospective interventional case series.

METHODS

Standard-fluence PDT using verteporfin.

OUTCOME MEASURES

Regression of tumor; resolution of subretinal fluid (SRF); change in best-corrected visual acuity (BCVA), and complications of PDT.

RESULTS

The study included 16 choroidal melanomas (3 pigmented, 4 lightly pigmented, 9 amelanotic) treated with adjuvant PDT after CyberKnife radiotherapy. The mean follow up time was 45.5 months after the initial PDT. 13 patients improved completely with PDT sessions and growth was seen in 3 patients. There was seen completely resolution in SRF in 10 eyes, partial resolution in 3 eyes, and stable in 3 eyes. The mean thickness of tumors was 3.9 mm before PDT and 2.3 mm after PDT. Retina pigment epithelium atrophy in 3 patients and subretinal hemorrhage in 1 patient were seen as complication of PDT. Three patients underwent enucleation for recurrence in the tumor. There was not a higher rate of change in BCVA after PDT (37.5% stable; 25% increase; 37.5% decrease. Poor final visual acuity associated with worse initial visual acuity, proximity of the tumor to the foveola and optic disc, and radiation complications.

CONCLUSIONS

PDT seems to offer a good option for posterior pole choroidal melanoma as adjuvant therapy in suitable cases. Future prospective studies with larger number of patients and with longer follow-up are needed to further investigation.