Dosimetry Test 3
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☆The Abdomen is defined as the portion of the body that lies between the _______ & the ________ and that contains the __________.
- PERITONEAL CAVITY
☆Generally speaking, the kidney tolerance dose to irradiation in the adult is:
2000 cGy delivered at 180 to 200 cGy per fraction
☆The most common site of pancreatic tumors is the ______ of the pancreas.
HEAD of the pancreas
☆Wilms' tumor is a tumor originating in the _______.
☆Neuroblastoma is a tumor most often originating in the __________.
Sympathetic Nervous System
often arising in abdomen, chest or neck
☆When pelvic irradiation is delivered in an obese patient in the supine position, the concern is that uncertainty of dose due to variations in patient _________ would be caused when attempts were made to eliminate skin folds.
uncertainty of DOSE due to variations in patient THICKNESS
☆To reduce the volume of __________ within a pelvic field, the patient's position should be prone on a belly board.
☆The primary purpose of a testicular shield is to reduce the amount of _________ dose in the testes.
INTERNAL SCATTERED dose in the testes
☆Of gynecological tumors treated with radiation therapy, the most common type is:
Squamous cell carcinoma of the Cervix
☆The depth of the deep inguinal nodes can vary from _____ to _____cm depending on the patient's size.
Dose rates _________ with field size.
(increase or decrease)
In the case of a patient that is unlikely to complete treatment, how should kidney shielding be accomplished?
Once the kidney tolerance dose has been reached, insert a 5-HVT block in the anterior & posterior fields
The dose under a 5-HVT kidney block is approximately ______ to ______% of the dose delivered at mid-depth on the central axis.
The amount of dose under a 5-HVT kidney block depends on the beam ________, the size of the _______, and the size of the ________.
- beam ENERGY
- size of the FIELD
- size of the KIDNEY BLOCK
The organs in which normal tissue tolerance is of concerns when treating pancreatic tumors are:
When a three field technique (anterior and lateral opposed fields) is used in the treatment of pancreatic tumors, the best dose distribution is achieved with wedge(s) in the ________ field(s) and more weighting on the ________ field(s).
- wedges in the LATERAL fields
- more weighting on the ANTERIOR field
When children are treated for Wilms' tumor, the medial field margin should be include the __________.
Width of the spine
What are three methods to reduce the volume of small bowel in the pelvis?
- 1. Surgically implanted expander
- 2. Mesh sling placement
- 3. Prone position
How much of the kidney should be excluded from the treatment field in order to preserve proper function?
2/3 of the kidney must be excluded
When patients with advanced cervical carcinoma are treated, the majority is delivered via ________.
External beam irradiation
A central pelvic shield is sometimes used in the treatment of opposed anterior and posterior fields following intra-cavitary irradiation to protect the _______, _______, and tissues irradiated to a high dose via the intra-cavitary implant
Due to the dome-like shape of the diaphragm in the anterior-posterior view, it is impossible to treat the entire abdominal cavity without also including some volume of ________ and _________.
Lung & Heart
Whole-abdominal treatment fields should be shaped to minimize the volume of irradiated ________ to reduce the risks of myelosuppression.
Insertion of a 1-HVT block in both fields during the entire course of treatment would deliver approx ______ of the dose in the shielded organs and the dose distribution under the shields would be similar to that of using ______ shields only during a portion of the treatment.
What are the three methods of kidney blocking?
- 1. Fully blocking the kidneys once tolerance dose is reached
- 2. Blocks that allow partial transmission of the beam for the entire treatment course
- 3. Fully shielding from one field only
☆The 10-year survival for patients with all stages of Hodgkin's disease is approximately:
☆The patient position for treatment of a mantle field in Hodgkin's disease is usually supine with the ________ extended and the arms __________.
- CHIN extended
- arm RAISED ABOVE THE HEAD
☆It is always important to align the patient with the ________ laser every day because if it is not, the field is rotated with respect to the patient's body.
☆Tattoos made in the patient's skin indicating irradiated areas can shift due to _______ and ________.
☆The advantages of ________ therapy are that it provides superior normal-tissue sparing and improved precision.
Intraoperative radiation therapy (IORT)
☆High- and low- dose total body irradiation is used in the preparation for a _________ and in the treatment of ____________.
- BONE MARROW TRANSPLANT (preparation)
- total dose: 900-1200 cGy
- CHRONIC LYMPHOCYTIC LEUKEMIA (treatment)
- total dose: 100-400 cGy
☆The most common position for patients receiving total-skin electron irradiation is ___________.
Standing with legs spread & arms raised
☆The main goal of radiation therapy in patients with bone metastasis is to prevent ________ and reduce _________.
- prevent FRACTURES
- reduce PAIN
☆In patients treated for a spinal cord compression, the treatment field should include approximately two ____________ in each direction beyond demonstrable disease.
approx TWO VERTEBRAL BODIES in each direction beyond demonstrable disease
Which 6 cancers commonly metastasize to the inguinal nodes?
- Distal third of the vagina
- Anal canal
- Uterine Cervix
*Vance Danced Under A Purple Umbrella Crazily*
Total skin electron irradiation (TSEI) is often used in the treatment of cutaneous diseases such as ________ and _________, where a high dose is needed in the first centimeter of tissue over the entire body while the underlying tissues are spared.
- Mycosis Fungoides
- Kaposi's Sarcoma (AIDS)
The total dose prescribed for TSEI treatment of mycosis fungoides is ________ and typically ____ to ____ electron beam energies are used in order to limit the amount of _________.
- 3600 cGy
- 4 to 6 MeV beams
What are the most common sites for bony metastases?
- Long bones in extremeties
________ lesions, which appear on x-rays as a less dense area in a bone, are most frequently associated with __________ or metastasis from malignant disease in breasts, kidneys, or the thyroid gland.
Lytic lesions (reduced bone density)
___________ lesions, areas that appear denser than bone on an x-ray, are often metastatic from the breasts, prostate gland, or Hodgkin's disease.
Osteoblastic lesions (increased bone density)
______ ______ photon fields can be used to spare underlying lung tissue when treating rib metastasis.
OPPOSED TANGENTIALS photon fields for rib mets
What is the average depth of the spinal cord?
4 to 6 cm
The average dose and fractionation schedule for multifocal brain metastasis treatment is _____ cGy in ____ week
_____ cGy in ____ weeks
- 2000 cGy in 1 week
- *3000 cGy in 2 weeks*
A typical treatment regimen of the cervix would include:
- 40-50Gy via a four field box
- ⇨ Cone down with midline block (MLB)
Patients with colorectal carcinoma are usually treated in the prone position, using ________ and ___________ fields.
- Opposed Lateral Wedged fields
- colorectal: prone ↡⇄ω
When treating a prostate tumor with a four-field box technique, the best rectal and bladder protection is achieved through _______ _______ fields.
Conformal Lateral fields
A __________ technique is usually the preferred field arrangement when treating bladder tumors.
power point indicates IMRT as tx of choice
When a posterior and opposed lateral fields with wedges are used to treat a rectal tumor, to reduce the hot spot under the thin portion of the wedges, one can _________ (increase/decrease) the weight on the lateral fields and ________________.
DECREASE the weight on the lateral fields
ADD an ANTERIOR FIELD
The gap between the mantle & para-aortic fields, assuming the same field length and SAD, is calculated and set correctly if the patient is in the same position and the _________ margin of the posterior para-aortic field coincides with the marker indicating the _________ margin of the anterior margin of the mantle field.
- Cephalad (superior)
- Caudal (inferior)
The most serious late consequence of high-dose TBI is __________ but thrombocytopenia occurs after _____ to _____ cGy.
100-150 cGy (thrombocytopenia)
When higher energy beams are not available to treat a prostate, heavier weight should be placed on the _________ & _________ fields.
Anterior & Posterior fields
Patients with cancer of the anal canal are usually treated with _______ and _______ fields.
45-50Gy w/ 15-20Gy boost
- Anterior & Posterior Wedged fields
Lesions in the lower 1/3 of the vagina require that the _______ and _______ lymph nodes be treated.
What does DICOM stand for?
Digital Imaging and Communications in Medicine
DICOM (Digital Imaging and Communications in Medicine) is an established standard format for the use and exchange of medical ________, media and ________ across a computer network. (a LAN or a WAN)
DICOM (Digital Imaging and Communications in Medicine) is an established standard format for the use and exchange of medical DATA, media and IMAGES across a computer network. (a LAN or a WAN)
Factors to consider in deciding btw an SSD or SAD technique are:
1. the importance of ________ in the particular patient
2. the amount of _____ delivered through the field
3. the actual _______ between the collimator and the patient's skin surface.
- 1. the importance of REPRODUCIBILITY in the particular patient
- 2. the amount of DOSE delivered through the field
- 3. the actual DISTANCE between the collimator and the patient's skin surface
Where is Point A located?
- 2cm superior of the external cervical os
- 2cm lateral to the uterine tandem
CT's operate in the energy range of _____ to _____ kev and are highly ___________.
- 20 to 140 kev
- highly collimated
Positron emission tomography utilizes beta ______ decay.
Pet = beta Plus
Nuclear medicine utilizes beta _______ decay.
nuke Med = beta Minus
Positron emission tomography is used because cancer cells metabolize ________ at a higher rate.
The primary particles involved in Magnetic Resonance are:
Electron, protons & neutrons which possess the quality called "spin"
Anatomical MRI's are _____ weighted while Functional MRI's are _____ weighted.
Patients are not to eat for ____ hours prior to a PET/CT.
NPO 6 hours
no exercise for 24 freaking hours!!!!
An off axis point is any point not on the ____________. The off axis point is used as a __________ point to tell the Dr what the dosage and effect on the tissue at that point will be as well as to find the __________.
often used w/ hodgkin's mantle fields
- any point not on the CENTRAL AXIS
- CALCULATION point
- Off Axis Ratio (OAR)
The iliac crest is at the level of ______ in the spine.
What is the typical width of spinal cord fields?
The staging system for Hodgkin's disease is the __________ system.
Ann Arbor system
A _______________ is a computer generated 2D radiograph displaying skeletal anatomy rendered from a three dimensional data set, such as CT or MRI.
Digitally Reconstructed Radiograph (DRR)
In a 3 field abdomen to treat pancreatic ca, increasing the weight of the anterior and left lateral fields or adding a posterior beam will decrease the dose to the ________.
In a 3 field abdomen to treat pancreatic ca, increasing the weight on both lateral fields would decrease the dose to the __________.
TD 5/5 of the bladder:
TD 5/5 of the heart:
TD 5/5 of the intestine:
TD 5/5 of the kidneys:
TD 5/5 of the salivary gland:
TD 5/5 of the rectum:
TD 5/5 of the spinal cord:
What is the most common intracranial tumor?
Metastatic disease from a primary tumor elsewhere in the body
What does ARRT, RT(T) stand for?
American Registry of Radiologic Technologists, Registered Technologist (Radiation Therapy)
When treating a whole abdomen, the _____ field is generally longer than the ____ field in order to treat the inguinal lymph nodes.
Wilm's tumor, which is primarily a tumor of the kidney (peds), has been know to metastasize to the ______ which requires ___________ treatments.
- metastasizes to the LUNG
- "whole lung" treatments
When tumors of the head of the pancreas, bile duct and distal stomach are treated, the _______ kidney is usually included in the treatment field.
When tumors of the body or tail of the pancreas, or tumors in the proximal & mid-gastric area are treated, the _______ kidney is often included in the treatment field.
A patient receiving TSEI and TBI use eye shields to protect the:
The effectiveness of an immobilization method is largely dependent on _______________.
Lymph nodes above the diaphragm treated in a typical Mantle field:
Lymph nodes below the diaphragm treated in a typical Hodgkin's:
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