Radthera prefi

Radiation Therapy

cornerstone of cancer treatment, aiming to deliver a precise dose of ionizing radiation to malignant tissues while sparing surrounding healthy structures.

geometric planning

Its required because it is where the reference point for beam setup determines how the dose is calculated and how the patient is

because:

•radiation falls of with distance (inverse square law)

•different reference points

•accurate geometry ensures:

tumor control, tissue protection, and reproducibility

why planning methods matter?

Source to Axis Distance (SAD)

distance from the radiation source to the treatment isocenter (the axis of rotation, usually located at the tumor or target volume).

size ka tumor ang gina basehan

isocenter

is a fixed point in space where multiple beams converge, regardless of gantry angle.

Source to Skin Distance (SSD)

distance from the radiation source to the patient's skin surface.

skin surface becomes the reference point for beam calibration and dose calculation.

Source-to-Tumor Distance (STD)

Directly measures the distance from the radiation source to the center of the tumor volume.

tumor ang gina basehan