4. Boost options

Reason for boost

to reduce spinal cord location

Boost options that take cord location into consideration

1. POP laterals

2. Wedge pair

3. 3 field technique

4. Obliques

5. APPA “Postage stamp”

6. HDR

T/F: Spinal cord depth varies along the cord

True

Where is the cord deeper?

superficial to deepest

1. Cervical

2. Thoracic

3. Lumbar

Purposes for HDR

1. boost technique

2. recurrent disease

3. obstructive disease

Typical dose for HDR

500cGy

2-4 txs

size of “postage stamp” field

4×4 to 5×5

On what pathologies of cancer are: APPA “postage stamp” boost used

1. Adenocarcinoma

2. Large Cell

Why would this field arrangement tend to be more useful for adenocarcinoma than for, say, squamous cell carcinoma or SCLC?

Squamous cell carcinoma & SCLC are centrally located so the APPA postage stamp field (even if its so small) would still tx spinal cord