Tx Techniques & Dose Distributions

What is the setup for a single field tx at 100cm SSD for the PA spine?

The setup involves a single field directed at the PA position

What does the 4 field ‘box’ tx technique involve?

AP and lateral orthogonal fields for isocenter setup, with the dose distribution shaped like a box

What are the two types of IMRT mentioned, and how do they differ?

Dynamic sliding window (Varian) and step-and-shoot (ELektra).

Dynamic - continuous dose delivery

STep-and-shoot - delivers dose in discrete steps

What is a characteristic of VMAT compared to other tx techniques?

VMAT does not have distinct entrance/exit portals and typically involves 18- pr 360 degrees arc

SBRT - define & how is it delivered?

Stereotactic Body Rad. Therapy; can be delivered via VMAT or IMRT, w/ maximum of 5 fractions

What are the components of breast setups in RT?

tangents on;y, or 3 field setup which includes tangents plus sclav (supraclavicular fields), or a 4 field setup which adds a posterior axillary boost (PAB)

WHat is the significant of the gantry angle in the sclav setup?

proper alignment and tx delivery, and the setup may include a half beam block at y1=0

What does the posterior axillary boost (PAB) involve in breast RT?

additional field used in conjunction w/ tangents and sclav to enhance dose to the axillary region

What is the beam and where is this treating?

PA spine

What is the beam?

AP/PA

WHat is the beam?

AP and laterals, 4 field box technique

What is the tx technique?

IMRT, 7 field bladder

What is the tx technique?

VMAT

WHat is the tx technique?

Tangential Breast

WHat is the tx technique?

SBRT