Lung Cancer: simulation and planning

Question 1

Arms up generally for

Answer 1

access
stability
tattoos

Question 2

Tattoos should be

Answer 2

-be in a stable position
-be clear and easy to use
-be cosmetically acceptable for patient
-not be large enough for error

Question 3

CT recommendations

Answer 3

-CT slice thickness ≤3mm (5mm max)
-IV contrast
-PET-CT recommended in certain situations or if for SABR
-include entire volume of both lungs FOR enabling accurate dose volume histogram generation

Question 4

3D Scan

Answer 4

patient moves thru scanner as it acquires images
slow scanners

Question 5

4D Scan

Answer 5

patients moves thru scanner, at each scan position it stops and takes images thru the whole breathing cycle (10 images per breathe)

Question 6

Breath Hold Scan

Answer 6

acquires a full scan at either end inspiration or end expiration breathe hold.

eliminates respiratory motion

Question 7

how is breathe hold achieve clinically

Answer 7

ABC/RPM/VisionRT

Question 8

4DCT Datasets

Answer 8

acquires a full scan at each phase of breathing

you can reconstruct these

CT 50%
MIP
AVIP

Question 9

Image Fusion

Answer 9

definition of tumour when atelectasis is present

Question 10

What are the relevant OARS?

Answer 10

spinal cord
oseophagus
heart
brachial plexus
lung

Question 11

OARS for SABR

Answer 11

chest wall/rib
bronchus/airways
stomach
liver
skin

Question 12

Volumes and Margins depend on

Answer 12

technique and scan acquisition

Question 13

GTV:
CTV:
PTV:

Answer 13

gross tumour volume = what can be seen , palpated or imaged
clinical tumour volume= GTV + margin for sub-clinical disease spread
planning target volume =allows for uncertainties in planning or treatment delivery.

Question 14

Why choose 3DCRT or IMRT?

Answer 14

tumour location
OAR promximity
dose painting
tumour motion-interplay effect