Brain Teaser #9

A) Question:

How many lobes are in the right lung, and how many lobes are in the left lung?

A) Answer:

The right lung has 3 lobes, and the left lung has 2 lobes.

B) Question:

On most people, at what anatomical level is the carina approximately located?

B) Answer:

The carina is located around the T5 region.

C) Question:

When comparing the various types of lung cancers, what type of lung cancer has the highest probability of metastasizing?

C) Answer:

Small cell lung cancer has the highest probability of metastasizing when compared to all other lung cancers.

D) Question:

This is the MOST common symptom for lung cancer?

D) Answer:

Cough is the most common symptom for patients with lung cancer.

E) Question:

What is the name of the syndrome that is caused by a lung tumor involving the sympathetic chain, resulting in ptosis?

E) Answer:

Horner's syndrome is the medical name caused by a lung tumor involving the sympathetic chain, resulting in ptosis.

F) Question:

When treating lung cancer, name three major organs to consider during radiation treatments. Please name them in order of most radiosensitive to least radiosensitive, and please assume whole organs.

F) Answer:

Three organs to consider when treating lung cancer with radiation from most sensitive to least sensitive are: lung (healthy), heart, and cord.

G) Question:

When treating with an AP/PA lung technique, what organ is usually of most concern?

G) Answer:

The cord is usually the organ of most concern when treating with an AP/PA technique.

H) Question:

If the Doctor needs to take the tumor up to a higher level after an AP/PA technique, what may the next technique be to limit cord dose?

H) Answer:

Going off cord and using oblique angles, when applicable, will help to reduce cord dose, thus allowing the tumor to be taken to an overall higher dose.

I) Question:

When using homogeneity correction factors for treating the lung, does your effective depth usually increase, decrease or remain the same when compared to your actual depth?

I) Answer:

Effective depth usually will be less then your actual when using correction factors for treating the lung. This is because if you assume the lung is air, then your effective (what you are really treating)is going to be a "smaller" depth when compared to normal tissue.

J) Question:

Lung is sometimes given a physical density correction factor of what value (approximate)? Please compare this to water, with a factor of 1.0.

J) Answer:

The correction factor that is sometimes used for the lung, is about .33 (33%) or 1/3 when compared to water (tissue).

K) Question:

If you have a 16 cm depth, but 9 cm is lung, what is the effective depth?

K) Answer:

Your effective depth would be 10.0 cm

16-9 = 7 cm (soft tissue)

7 soft tissue + (.33 correction factor)(9 lung) = effective depth

deff= 10.0 cm


Author: Adam Buell
Editors: Mary Hare and Joan O'Brien
Date Created: August 2005