Assignment 3

Question 1

what is the most common bone tumor in children?

Answer 1

osteogenic sarcoma

Question 2

What is the second most common bone tumor in children?

Answer 2

Ewing sarcoma

Question 3

Is Ewing sarcoma more prevalent in boy or girl children?

Answer 3

Boy children

Question 4

What is the most common site of Ewing sarcoma?

Answer 4

lower half of the body

25% in the pelvis and 17% in the femur

Question 5

What is the most frequent presentation of Ewing sarcoma?

Answer 5

pain and swelling

Question 6

What part of the bone is a more common site of Ewing sarcoma?

Answer 6

diaphysis

Question 7

What is the classic appearance of Ewing sarcoma on a radiograph?

Answer 7

diaphyseal tumor with involvement of the medullary cavity (known as “onion skin appearance”) and an associated soft tissue mass

Question 8

How does Ewing sarcoma frequently metastasize?

Answer 8

through the blood stream

Question 9

About what percentage of Ewing sarcoma patients have mets at the time of diagnosis?

Answer 9

25%

Question 10

What are the most common metastatic sites of Ewing sarcoma?

Answer 10

bone, bone marrow, and the lungs

Question 11

In most cases, why would post-operative XRT be recommended after conservative surgery?

Answer 11

to treat positive margins

Question 12

What is the definition of hyperfractionation?

Answer 12

“Fractional doses smaller than conventional, delivered two or three times daily to achieve an increase in the total dose in the same overall time”

Question 13

Fractional doses smaller than conventional, delivered two or three times daily to achieve an increase in the total dose in the same overall time

Answer 13

hyperfractionation

Question 14

Describe the special attention that should be paid to field borders when radiating children?

Answer 14

Strict attention should be paid to field borders when radiating children due to bone growth. When the tumor is near a long bone, the uninvolved epiphysis should be spared to reduce (negative) late growth effects. For flat bones (e.g. vertebrae) the entire bone is included. For ribs with cytologically positive effusion (cancerous cells in fluid), the entire pleural cavity is included.

Question 15

When radiating extremities, why is a narrow strip of normal tissue spared?

Answer 15

to prevent lymphedema

Question 16

Are the majority of bone lesions primary or metastatic?

Answer 16

Metastatic

Question 17

Where does metastatic bone disease most often occur?

Where is it uncommon?

Answer 17

spine, pelvis, femur, and humerus

Radius, ulna, tibia, fibula, hands & feet

Question 18

What are the most common cancers to metastasize to bone?

Answer 18

lung, breast, and prostate

Question 19

What is the definition of debulking?

Answer 19

Surgical procedure used to reduce tumor size, reduce tumor burden, and increase the opportunity to obtain a pathologic diagnosis.

Question 20

List 2 radiopharmaceuticals that are used to treat pain from bone mets.

Answer 20

Sr-89 (Strontium-89) and SM-153 (Samarium-153)

Question 21

What are the 2 most common locations for primary bone tumors?

Answer 21

the distal femur and proximal tibia

Question 22

Where are osteosarcomas most commonly found?

Answer 22

distal femur, followed by the proximal tibia and proximal humerus

Question 23

Where are chondrosarcomas typically found?

Where are they rarely found?

Answer 23

in the pelvis and femur

the distal extremities

Question 24

Where do MFHs and GCTBs typically arise?

Answer 24

in the metaphysis and epiphysis of long bones, including in the distal femur, proximal tibia, and distal radius

Question 25

TD 5/5: bone

Answer 25

5200 c/Gy

Question 26

TD 5/5: bone marrow

Answer 26

2500 c/Gy

Question 27

TD 5/5: skin

Answer 27

5500 c/Gy