dosi 2 tx planning thorax and breast

what is the most common cancer in US

lung

why is lung the most common cancer in US

smoking, asbestos exposure, occupation

what cancer is relatively uncommon in the US, very common in some areas of china

esophagus

what can esophageal cancer be due to

smoking, alcohol, nutrion

what is ratio of male to female lung cancer

1:1

what percent do the 2 groups make up of lung cancers

90%

what percent is NSCLC

80%

what percent is squamous NSCLC

25%

which NSCLC is associated with smoking

squamous

where is most squamous NSC lung cancers seen

central location

what percent is adenocarcinoma of NSCLC

40%

what location is adeno NSCLC

peripheral location

what cancer of NSCLC is increasing incidence

adeno

adeno NSCLC is not associated with _

smoking

what type of NSCLC is undifferenitated

15%

what is the tx of choice for all NSLC

surgery

what percent is SCLC

20%

another name for SCLC

oat cell

which has the poorest prognosis of lung cancer

SCLC

where does SCLC typically met

brain

what is tx choice for SCLC

chemo

what is total dose to curative tx of NSCLC

5400-7500

what is the palliative total dose for NSCLC

4000-5000

what is the small cell adjuvat total dose

4500-5500

what is the total dose for brain for mets of SCLC

2500

what is heart 1/3 of td5/5

6000

what is heart 2/3 of td5/5

4500

what is heart 3/3 of td5/5

4000

what is endpoint of td5/5 for heart

pericarditis

what is esophagus 1/3 of td5/5

6000

what is esophagus 2/3 of td5/5

5800

what is esophagus 3/3 of td5/5

5500

what is endpoint for esophagus for td5/5

stricture/perforation

what is lung 1/3 of td5/5

4500

what is lung 2/3 of td5/5

3000

what is lung 3/3 of td5/5

1750

what is endpoint for lung td5/5

pneumonitis

what is brachial plexus 1/3 of td5/5

6200

what is brachial plexus 2/3 of td5/5

6100

what is brachial plexus 3/3 of td5/5

6000

what is endpoint of brachial plexus for td5/5

clinically apparent nerve damage

what is the choice of position based on in thorax

long range of tx plan, pt mobility, reproducibility, availability of immobilization devices

what will movement during respiration of thorax determine

PTV

what are limiting factors for dose during lung cancers

cord, heart, lung

what were some historic ports in lung

ant/post, then reduced off cord

what fields limit dose to cord but increase dose to lung and heart

obliques

the steeper the obliques, the more dose will be received by _

lung and heart

what are some disadvantages of ant/post fields to lung

dose gradient resulting from slope of chest

where will dose be higher on ant/post fields lung

superior portion

what provides high dose of rad to very small field of lung

endobronchial high dose rate

HDR =

> 12Gy/hr

what sources are used for lung HDR

192Ir

what is half life of 192Ir

74.1

what is the typical dose per fx for HDR lung

500

LDR rate

2gy/h

what is MDR rate

2-12gy/h

what can increase with brachy dose eate

biological effect

what are challenges in the tx of esophagus

position/depth within chest, spinal cord, skip mets

what margin for extent of esophageal disease

5cm

what is the curative intent dose for esophagus

6500 (5000 w chemo)

what are the most common fields for eso tx

anterior and 2 posterior

what is total dose breast tangents

4600-5000

what is electron boost breast total dose

6000-6600

what is chestwall total dose

4500-5000

what is supra/axilla total dose

4500-5000

what beam arrangement for breast

opposed tang

what beam arrangement for chestwall

opposed tangent field or appositional electron fields

what beam arrangement for supra

anterior field only, 10-15 mediolateral gantry angle

why do you need a 10-15 mediolateral gantry angle on supra

avoid trachea, eso, and cord

what beam arrangement for axilla

posterior only, with qs dose prescription

what beam arrangement for IM nodes

include in medial tangents, anterior field angled to abut tangent, anterior direct field (electron)

qs =

quantity sufficient

what does qs mean

giving the amount of rad sufficient to give a prescribed amount of rad to a specific field

what depth is the supra field typically prescribed tx to

3cm

what depth is the PAB typcially prescribed tx to

midline

why is it difficult to deliver uniform dose to entire breast

due to irregular shape of breast tissue

what kind of angle do pts with large breast require

less wedge angle

why are wedges necessary to small breast or chestwalls pts

contour with steep curvature

what helps extend the variation in wedge effect to meet particular needs of a pt

mixing open and wedge fields

estimated 1.5cm lung = _ of lung volume

6%

estimated 2.5cm lung = _ of lung volume

16%

what do cosmetic results seem to be dependent upon

dose and time after reconstruction

what dose per fx gives minimum fibrosis and shrinkage of breast

4500 @ 180/day

what is needed to have the best cosmesis with time

more time bt sx and tx

what does a ring do to hold breast for tx

reduce lateral fall of breast and move breast more cephalad