COMPREHENSIVE QUIZ TOTAL SET- TREATMENT PLANNING

The density of lung and bone are..

0.3 g/cm3; 1.65 g/cm3

The treatment borders for a spinal cord compression are typically: 1. 3-4 cm above and below the cord compression. 2. 8 cm wide, but vary according to the lateral extent of the tumor 3. Extend laterally to include all thoracic lymph nodes 4. 5 vertebral bodies above and below the cord compression

1, 2

In HDR implants, central doses are prescribed to Point A and Point B. Which statements are correct... 1. Point A is defined as 2 cm superior to the cervical os. 2. Point A is defined as 3 cm superior to the cervical os. 3. Point A is defined as 2 cm lateral to the endocervical canal 4. Point B is defined as 2 cm lateral to point A.

1, 3

What are the 3 ways that tissue inhomogeneities effect dose deposition. 1. Primary photons attenuated differently. 2. Different Materials influence the scatter of radiation. 3. Secondary electron fluence alterations. 4. Lungs cause more attenuation. 5. Bone transmits more photons.

1,2,3

Which of the pelvic nodes should be included in the CTV for high risk prostate cancer? 1. presacral 2. distal common iliac 3. internal and external iliac 4. obturator

1,2,3,4

For a tumor surrounded by lung, it is difficult to get good dose coverage because... 1. There is a new build-up region in the tumor after the radiation travels through lung. 2. The tumor is too deep. 3. Loss of secondary electrons (electronic equilibrium). 4. The lung tissue absorbs too much dose.

1,3

The equivalent square of a rectangular field... 1. has the same PDD on axis as the rectangular field 2. is approximately twice the area divided by perimeter 3. has the same BSF as the rectangular field 4. has the same area as the rectangle

1,3

A patient is to receive cranial spinal irradiation. The brain field is 24 x 30 cm. The thoracic spine field is 8 x 32 cm at 100 SSD. The lumbar spine field is 12 x 28 cm at 100 cm SSD. The spine fields are to be planned using a 3.5 cm depth. What is the gap needed between the spine fields?

1.05 cm

In order to match adjacent spine fields at a depth of 5.5 cm, using 6 MV photon fields each with a length of 26 cm, the gap that should be left on the skin between the light field edges is ______cm.

1.4

What dose rate is used to treat TBI?

100 cGy/min

A standard TBI regimen is....

1200 cGy in 6 fx

Qualitative Analysis of Normal Tissue Effects in the clinic data suggest when sparing one parotid, the mean dose should not exceed...

20 Gy

Radiation to the abdomen for soft tissue sarcomas in the peritoneum is limited by low tolerance organs such as the kidneys. The TD 5/5 for the whole kidney is:

2300 cGy

Qualitative Analysis of Normal Tissue Effects in the clinic data suggests when bothparotid glands are spared, the mean dose to both glands should not exceed...

25 Gy

What is the average survival for patients with brain metastasis?

3 months

Palliative doses for brain metastasis are typically...

300 cGy per fraction, total dose of 30-45 Gy.

What is the typical treatment dose for multiple myeloma?

3000 cGy

What percentage of Hodgkin's patients present with B-symptoms?

33%

A patient receiving total body irradiation is typically treated at..

400-500 cm

When radiation is the primary treatment of cervical cancer, the tumor and regional lymphatics are treated to....

45 - 50 Gy

The TD 5/5 for the whole brain is...

4500 cGy

Which external beam RT dose prescription is the most appropriate for a patient with bladder cancer?

45Gy + 15Gy Boost

The Quantec recommended maximum dose to the spinal cord when utilizing conventional fractionation is.....

5000 cGy

The TD 5/5 for the optic chiasm is....

5000 cGy

The TD 5/5 of the optic nerve is...

5000 cGy

What is the TD 5/5 for the brainstem?

5000 cGy

For carcinoma in situ and stage I well-differentiated cancer, the entire vagina may be treated with low dose rate brachytherapy using a vaginal cylinder, with cesium-137 to a dose of:

6000 cGy

The TD 5/5 for the cauda equina is...

6000 cGy

The normal brain tolerance dose (TD 5/5) of 1/3 of the brain is approximately....

6000 cGy

The TD 5/5 for whole bladder is.

6500 cGy

The overall 5 year survival rate for cervical cancer is...

70%

A curvative radiation dose for larynx cancer would be....

7000 cGy

A patient is to receive cranial spinal irradiation. The brain field is 24 x 30 cm. The thoracic spine field is 8 x 32 cm at 100 SSD. The lumbar spine field is 12 x 28 cm at 100 cm SSD. The spine fields are to be planned using a 3.5 cm depth. What is the couch kick needed?

8.5 degrees

A field measuring 5 x 30 cm has an equivalent square field of...

8.6 cm

A patient presents with cervical cancer, the primary tumor can be boosted with intracavitary brachytherapy to doses of...

80 -85 Gy

A patient is to receive cranial spinal irradiation. The brain field is 24 x 30 cm. The thoracic spine field is 8 x 32 cm at 100 SSD. The lumbar spine field is 12 x 28 cm at 100 cm SSD. The spine fields are to be planned using a 3.5 cm depth. What is the collimator angle needed?

9.1 degrees

Use Sterlings formula to calculate the eq. square for a 6 x 20 field.

9.2

QUANTEC states when using standard 1.8 cGy/fraction, the rectal V65 should be___________?

<25%

QUANTEC states that when utilizing standard 1.8 cGy fractionation, the rectal V50 should be____________?

<50%

QUANTEC states the bladder V65 for a patient receiving standard 1.8 cGy/fraction prostate irradiation is_________?

<50%

When planning an AP/PA right femur soft tissue sarcoma, the field length should include a ___________margin.

>5cm

A post-operative radiation dose for a soft tissue sarcoma would most likely be...

>6000 cGy

A beam spoiler utilized for a 10 MV head and neck treatment would decrease the dose to the superficial nodes.

A beam spoiler would increase dose to the superficial nodes. The correct answer is 'False'.

What is most common childhood malignancy?

ALL

T/F: The TAR ratio method takes into account the point of interest relative to the inhomogeneity and scatter.

FALSE

T/F: You should always use a high energy when treating lung tumors.

FALSE

Coating lead shields with wax increases backscatter.

False

If you use the half beam block technique for a 3 field head and neck, you must kick the table and rotate the collimator on the lateral fields.

False

Metastatic brain disease typically presents as a solitary lesion.

False

Standard dose for a cord compression is 800 cGy in 1 fx.

False

When planning cranial spinal irradiation, the couch should be kicked away from the gantry to prevent divergence of the whole brain field into the thoracic spine field.

False

Which of these would not be used for a prostate LDR implant?

Iridium-192

What is the most common mode of spread for cancer?

Lymphatics

TAR at d-max can be calculated from the BSF by:

No need to calculate they are the same at d-max

All of the following are independent of SSD except:

PDD

Which of the following isotopes may be used in treatment for ovarian cancer?

Phosphorus-32 (P-32)

Primary osseous tumors metastasize to the lung via:

Primary tumors originating in compact bone metastasize to the lung through the blood. Ref. Mosby's The correct answer is: blood

Which of the following radionuclides may be used in treating metastatic bone disease?

Strontium-89

The primary treatment of choice for local control of soft tissue sarcomas located in the extremities is...

Surgery

T/F: When planning an AP/PA soft tissue sarcoma of the humerus, the field width should exclude a small strip of tissue to prevent lymphadema.

TRUE

T/F;A CT density phantom is used to provide the planning system with electron density vs CT number data.

TRUE

In reference to Whole Brain treatment, inhomogeneities across the superior thinned parts of the head can be reduced by...

Utilizing a field-within-a-field technique

It is easy to measure Sp (phantom factor) for an 18 MV beam.

You can't measure Sp directly because collimator scatter will always be included. The correct answer is 'False'.

Percent Depth Dose is defined as... Select one: a. The ratio of the dose at depth d in a phantom to the dose at some reference depth. b. PDD (d) = (Dose d/ Dose reference depth) x 100 % c. The ratio of the dose at depth d in a phantom to the dose at the same point in air.

a&b

Conventional field borders for whole pelvis cervical irradiation include... Select one: a. The Anterior field superior border located at the level of L3/L4 b. The Anterior field lateral borders located 2 cm lateral to the bony pelvis c. The Right Lateral field posterior border located at the posterior edge of the sacrum d. The Anterior field inferior border located at the superior portion of the obturator foramen

a, b, c only

Which of the following is true regarding lung inhomogeneities? Select one: a. density is 0.3 g/cm3 b. they have no effect on the dose distribution c. lack of scatter can cause cold spots in tumors d. radiation is attenuated more in lung so dose after lung decreases

a, c

The FIGO staging system is utilized for cervical carcinoma. Which of the following statements is/are correct? Select one: a. Stage IIIA involves the lower third of the vagina b. Stage IA, the tumor is >4 cm c. Stage IVA, spread outside the true pelvis d. Stage IIA, upper vaginal spread

a, c, d

Risk factors for the development of squamous cell carcinoma of the cervix include... Select one: a. HPV b. Alcohol Consumption c. Cigarette Smoking d. Race

a, c, d only

The following is/are methods for correcting for Tissue Inhomogeneities..... Select one: a. TAR ratio method b. Power Law (Batho) method c. Sector Integration d. Equivalent TAR method e. a, c, d f. a, b, d

a,b,d

T/F: The surface dose to a patient receiving total body irradiation can be increased by utilizing a beam spoiler/degrader.

true

Rhabdomyosarcoma may occur... Select one: a. in the chest b. in extremities c. in the head and neck region d. all of the answers are correct e. in urinary and reproductive organs

all of the answers are correct

For an electron beam incident on a phantom with a single inhomogeneity in the phantom. The hotspot will occur...

along the posterior edge of the inhomogeneity

Given the following data, calculate the corrected PDD value using the TAR ratio method. d1 = 3 d2 = 8 d3 = 3 p1 = 1 pe = 0.3 p3 = 1 field size = 12 x 12 PDD (14, 12 x 12, 6x) = 55.6

d' = d1 + ped2 + d3d' = 3 + (0.3)(8) + 3 = 8.4 cmCF = TMR (8.4, 12 x 12) / TMR (14, 12 x 12) = 0.840/0.689 = 1.22Corrected PDD = 55.6 x 1.22 = 67.8% The correct answer is: 67.8%

Cranial spinal fields are feathered to help avoid hot/cold spots, this is done approximately....

every 5th treatment or every 1000 cGy

A patient being treated for a small volume bladder cancer should....

have an empty bladder

PDD's _____________ with increasing SSD because of ____________.

increase, ISL

With regard to Energy, Depth, Field Size, and SSD; Do PDD's increase or decrease?

increase, decrease, increase, increase

The TMR at D-max:

is always 1.0

Lymphatics of the tongue drain chiefly into what nodes?

jugulodiagastric

The most common location of metastases for Ewing's sarcoma is:

lungs

If no surgery has been performed, what total dose should you go to for soft tissue sarcomas (pre-op)?

pre-op 50 Gy post-op 60-70 Gy

The seminal vesicles are situated:

superior to the prostate and angled posteriorly near the rectum

Early stage cervical cancer (stage IA) is treated primarily with....

surgery

Pediatric brain tumors are most commonly located in...

the posterior fossa

The spine field of cranial spinal irradiation extends caudally to...

the sacrum to include the SI joints

What is the most common type of bladder cancer?

transitional cell carcinoma

T/F: Soft tissue sarcomas primarily arise from mesenchymal cells.

true