Blood flow velocity in monocular retinoblastoma assessed by color Doppler

[Angioarchitecture of small retinoblastomas: the role of optical coherence tomography angiography]

Optical coherence tomography angiography (OCTA) is a non-invasive diagnostic method used in children and adults. Features of angioarchitecture of small retinoblastoma are not sufficiently covered.

PURPOSE

The study investigated the angioarchitecture of small retinoblastomas using OCTA.

MATERIAL AND METHODS

The study included 10 children with binocular retinoblastoma aged 2.7±0.5 months with small tumors of central localization (10 foci). The tumors were divided into 3 groups: group 1 (n=4) - tumor thickness 0.8±0.2 mm; group 2 (n=3) - 1.6±0.5 mm; group 3 (n=3) - 2.4±0.8 mm. OCTA was performed on Spectralis HRA+OCT (2460 scans in total). Vessels were identified in the superficial, deep and outer layers of the tumor on En Face images. Their average number was estimated by visualization of yellow pixels in the superficial layers on 10 sagittal sections. Statistical analysis was done using Microsoft Excel, Statistica 8.0. The Kruskal-Wallis H test was used for comparative analysis of independent variables with more than two samples.

RESULTS

Retinal vessels with feeding anastomoses connecting them to multiple small tortuous tumor vessels in the superficial layers were identified in group 1. Number of yellow pixels - 16.5±0.5. In the deep layers - single chaotic vascular arcades. In flat small retinoblastomas the vascular component was not evaluated. In group 2 in the superficial layers of the tumor we found multiple geniculate vessels of large and small caliber anastomosing between themselves and the retinal vessels. Number of yellow pixels was 21±0.8. A few vessels were identified in the deep and outer layers. In group 3 we identified single convoluted vessels in the superficial layers with glow and quantity increasing in the deep layers. In the deep layers - emergence of a small number of vessels. The maximum number of multiple own tumor vessels was determined in the outer layers. Number of yellow pixels - 10±0.8.

CONCLUSION

The obtained results confirm the possibility to preclinically identify the angioarchitecture of small retinoblastomas in order to determine the activity of tumor growth and serve as a marker of neoplasm regression in the future, after organ-preserving treatment.

Blood Flow in Monocular Retinoblastoma Assessed by Color Doppler and Correlations With High-Risk Pathologic Features

Purpose

To use color Doppler to analyze blood flow in the retrobulbar central retinal artery (CRA) and central retinal vein (CRV) in monocular retinoblastoma.

Methods

This prospective study included patients with group D and E retinoblastomas managed with only enucleation. Peak blood velocities were assessed in the CRA and CRV of tumor-containing eyes (CRAv and CRVv, respectively). The resistivity index in the CRA (RIa) and pulse index in the CRV (PIv) were calculated and related to optic nerve invasion (ONi), choroid invasion (mCHi), and tumor volume. RIa and PIv were also calculated for healthy eyes.

Results

In total, 25 patients with a mean age of 30.8-months old were included. The means (SD) for CRAv, CRVv, RIa, and PIv were 26.94 (12.32) cm/s, 16.2 (9.56) cm/s, 0.88 (0.12) and 0.79 (0.29), respectively. Tumor volume was significantly correlated with CRAv (P = 0.025) and RIa (P = 0.032). ONi was present in 19 eyes and correlated with a smaller PIv (P < 0.001). A PIv less than 0.935 had a sensitivity of 89.5% and specificity of 83.3% for predicting ONi. mCHi was not correlated with flow values. Healthy eyes had a significantly lower RIa (P < 0.001) and lower PIv than eyes with (P = 0.009) and without (P < 0.001) ONi.

Conclusions

In advanced-stage monocular retinoblastoma, tumor volume was directly correlated with CRAv and RIa, and lower PIv was correlated with optic nerve invasion when a predictive cut-off value of less than 0.935 was applied. Comparisons with healthy eyes showed that tumor-containing eyes were associated with higher RIa and PIv values.