TD 5/5

Question 1

Please select the TD 5/5 and the endpoint for the spinal cord

Answer 1

47 Gy & Necrosis

Question 2

Please select the TD 5/5 and the endpoint for the lens.

Answer 2

1000 cGy & Cataracts

Or 10 Gy

Question 3

Please select the TD 5/5 and the endpoint for the optic nerve.

Answer 3

50 Gy & Blindness

Question 4

Please select the TD 5/5 and the endpoint for the parotid gland

Answer 4

32 Gy & Permanent xerostomia

Question 5

Please select the TD 5/5 and the endpoint for the temporomandibular joint.

Answer 5

6000 cGy & Limitation of joint function

Question 6

Please select the TD 5/5 and the endpoint for the thyroid

Answer 6

4500 cGy & Thyroiditis

Question 7

Please select the TD 5/5 and the endpoint for the esophagus.

Answer 7

5500 cGy & Stricture or perforation

Question 8

Please select the TD 5/5 and the endpoint for the larynx

Answer 8

4500 cGy & Edema

Question 9

Please select the TD 5/5 and the endpoint for the heart.

Answer 9

4000 cGy & Pericarditis

There is an issue with the heart and this question. The heart itself is a muscle and can take a higher dose of radiation without damage. However, much of the connecting tissue cannot tolerate the same dose without suffering damage. Thus, it depends on what structures are considered when setting the TD 5/5. Generally, it is 3000 cGy or 4000 cGy.

Portal Design in Radiation Therapy 3rd edition, page 71

TD 5/5 for 3/3 of organ is 40 Gy followed by Pericarditis

Principles and Practice of Radiation Therapy 4th edition, page 632

Heart tolerance for the whole organ is 25 Gy followed by mortality

Heart pericardium tolerance is 30 Gy followed by pericarditis

It further suggests, a TD 50/5 for the heart is 30 Gy fololwed by percarditis

Question 10

Please select the TD 5/5 and the endpoint for the lung.

Answer 10

17 Gy & Pneumonitis

Question 11

Please select the TD 5/5 and the endpoint for the brachial plexus.

Answer 11

55 Gy & Brachial plexopathy

Question 12

Please select the TD 5/5 and the endpoint for the liver.

Answer 12

3000 cGy & Liver failure

Question 13

Please select the TD 5/5 and the endpoint for the kidney.

Answer 13

23 Gy & Nephritis

Question 14

Please select the TD 5/5 and the endpoint for the stomach.

Answer 14

5500 cGy & Ulceration and/or perforation

Question 15

Please select the TD 5/5 and the endpoint for the small bowel.

Answer 15

45 Gy & Obstruction and/or perforation

Question 16

Please select the TD 5/5 and the endpoint for the large bowel.

Answer 16

4500 cGy & Obstruction and/or perforation

Question 17

Please select the TD 5/5 and the endpoint for the femoral head and neck.

Answer 17

5200 cGy & Necrosis

Question 18

Please select the TD 5/5 and the endpoint for the bladder

Answer 18

65 Gy & Contracture

Question 19

Please select the TD 5/5 and the endpoint for the brain (limited).

Answer 19

60 Gy & Necrosis and/or infarction

Question 20

Please select the TD 5/5 and the endpoint for the brain (whole).

Answer 20

4500 cGy & Necrosis and/or infarction

Question 21

Please select the TD 5/5 and the endpoint for the brain stem.

Answer 21

5000 cGy, necrosis and/or infarction

Question 22

Please select the TD 5/5 and the endpoint for the retina.

Answer 22

45 Gy, blindness