Seed diagrams for 10 mm–22 mm COMS-plaques when viewed from the concave aspect of the Silastic insert. Rotational orientation of the Silastic seed carrier insert within the gold-alloy backing (relative to the suture eyelets) is arbitrary. The zp axis (not shown) is pointing out of the image and toward the eye center. Note the angle ϕ defined as the angle between the +xp axis and the projection onto the x-y plane of the line passing through the seed center is shown in the diagram for the 10 mm plaque (upper left). This definition of angle ϕ applies to all plaque sizes.
Side view diagram of 14-mm COMS plaque, illustrating the gold-alloy backing and Silastic insert with seed grooves accommodating seeds (gray circles and rectangle) in idealized positions. The Silastic insert is 1 mm thick between the groove and the concave surface of the insert. The coordinate system origin is located at the inner sclera along the plaque central axis. The zp-axis is pointing toward the eye center, the xp-axis points away from the suture lug, and the yp axis (not shown) points into the figure.
Retinal/fundus diagram (upper) and transverse cross section diagram (lower) of standard eyes with 22-mm inner diameter: (a) right eye, and (b) left eye. In the fundus diagrams, the numbers indicate chord and arc lengths (in parentheses) in mm between two points in the retina. The fovea is at the center of the three concentric rings, which represent equator, ora serrata, and limbus from inside out, respectively. The small circle next to the fovea indicates the optic disc. The slightly larger dotted circle outside the optic disc indicates the projection of the outer circumference of the optic nerve sheath. The 12 clock hours indicated by numerals 1–12 (outside the outermost circle) are used to identify the locations of anatomical structures in an eye. In the cross section diagrams, only the chord lengths (in mm) are shown. Note that the actual dimensions of the eye vary and the eye is not a perfect sphere.
Coordinates (millimeters) of seeds for the 10 mm–22 mm diameter COMS standard eye plaques. The seed physical length was set to 4.5 mm. Physical positioning of the seed # assignment is shown in Fig. 1. The COMS reference coordinate system origin at (xp = 0, yp = 0, zp = 0) is defined at the inner sclera along the plaque's central axis. The angle ϕ is the angle between the +xp axis and the projection on the x-y plane of the line from the origin to the seed center. As an example, the definition of the angle ϕ is shown in the diagram for 10 mm plaque in Fig. 1. In this example, ϕ = 45° for seed # 3.
Central-axis dose values (in Gy) of the Homo and Hetero cases for all seven COMS plaque sizes (10 mm–22 mm), with the Homo dose normalized to 85 Gy at a depth of 5 mm for a given plaque size. Data are for model 6711 and model 200 seeds for 125I and 103Pd, respectively, from simulations with BrachyDose (Ref. 54).
Values of the dose correction function T(r) for a single seed in a COMS plaque at various transverse distances r from the seed center used in the Plaque Simulator calculations for 125I (model 6711) and 103Pd (model 200) seeds (Ref. 58).
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