Treatment planning Chapter 13(pelvis)

  1. When pelvic irradiation is delivered in an obese patient, the advantage of a prone treatment is..?
    Skin marks are more reliable to set up fields

    *also, skin fold reactions are reduced
  2. *****When pelvic irradiation is delivered in an obese patient in the supine position, the concern is that
    (*hint how are skin folds reduced in supine obese patients and how does that effect the setup)
    Uncertainty of dose due to variations in patient thickness would be caused when attempts were made to eliminate skin folds(through taping, etc...hard to reproduce)
  3. ****To reduce the volume of small bowel within a treatment field...?
    The patient should be prone on a belly board
  4. Methods to reduce the volume of small bowel in the pelvis include(name 3)
    • 1)surgically implanted expander
    • 2)placement of a mesh sling(also surgical)
    • 3)prone position
  5. When a pelvic 4-field technique is used for treatment of a carcinoma of the cervix is simulated, which of the following should be used(name 4)
    • 1)small bowel contrast
    • 2)rectal contrast
    • 3)contrasted enhanced vaginal cylinder
    • 4)gold seed in the inferior aspect of the palpable or visible tumor
  6. A patient has a large pelvic tumor that involves the bladder and prostate and there is a presacral mass. Therefor, the treatment should be given through a ___field technique because is is possible to shield normal tissues within the _____ portion of the ______fields.
    • A patient has a large pelvic tumor that involves the bladder and prostate and there is a presacral mass. Therefor, the treatment should
    • be given through a 4 -field technique because is is possible to shield normal tissues within the cephalad portion of the lateral fields.
  7. Patients with carcinoma of the cervix are treated with a combination of external beam and  intracavity irradiation. However, in patients with more advanced disease, a  (larger/smaller) proportion of the dose is delivered via ______.
    Patients with carcinoma of the cervix are treated with a combination of external beam and  intracavity irradiation. However, in patients with more advanced disease, a  larger proportion of the dose is delivered via external beam irradiation..
  8. A central pelvic shield is sometimes used in the treatment of opposed anterior and posterior fields following intracavity irradiation to protect (name 3) irradiated to a high dose via intracavity implant.
    • A central pelvic shield is sometimes used in the treatment of opposed anterior and posterior fields following intracavity irradiation to
    • protect the bladder, rectum, and tissues irradiated to a high dose via intracavity implant.
  9. Treating the pelvis and para-aortic lymph nodes in separate fields (is or is not) preferred because of __________.
    Treating the pelvis and para-aortic lymph nodes in separate fields is not preferred because of concerns regarding field matching.
  10. Treating the whole pelvis and inguinal node can be done using one of the following techniques:?
    Delivering 100% of the prescribed inguinal dose via an anterior pelvic and inguinal field with a pelvic attenuator, made to a thickness that allows 50% of the midpelvic dose to be delivered via this field while 50% of the pelvic dose is delivered via a posterior field covering the pelvis only.
  11. In a 4-field box technique, used to treat a prostate tumor, the best rectal and bladder protection is achieved through_____?
    conformal lateral fields
  12. When bladder tumors are treated, the field arrangement is usually ____?
    a 4-field box technique

    *empty bladder
  13. When posterior and opposed wedged lateral fields are used to treat a rectal tumor, to reduce a hot spot under the thin portion of the wedge, we can_____?
    add an anterior field and decrease the weight on the lateral fields
  14. When a patient treated for rectal carcinoma is treated in the prone position as opposed to the supine position the skin reaction ______ _______ ________ is (reduced/increased).
    • When a patient treated for rectal carcinoma is treated in the prone position as opposed to the supine position the skin reaction between the
    • buttocks is reduced.
  15. *****The primary purpose of a testicular shield is to reduce the amount of ______  ______  dose to the testes.
    The primary purpose of a testicular shield is to reduce the amount of internal scattered dose to the testes.
  16. To insure the inclusion of the inferior aspect of a vaginal lesion in the treatment fields:___?
    To insure the inclusion of the inferior aspect of a vaginal lesion in the treatment fields a radiopaque  gold seed should be inserted into the inferior aspect of the tumor prior to simulation.
  17. When a large patient is treated for a pelvic tumor using a 4-field box technique_____(what could be a problem?).
    When a large patient is treated for a pelvic tumor using a 4-field box technique secondary scatter from the collimator and block trays may be a problem.
  18. ******Of gynecologic tumors treated with RT, the most common type is________?
    squamous cell carcinoma of the cervix
  19. For small bowel contrast during simulation of a 4-field pelvic plan, the patient should drink the barium _________hrs prior to simulation?
    1-1.5 hrs prior to simulation
  20. ******The depth of the deep inguinal lymph nodes can vary from ___-_____cm depending on the patient's size.
    The depth of the deep inguinal lymph nodes can vary from 2-18 cm depending on the patient's size.
  21. What is DICOM?
    • Digital Imaging and Communications in Medicine
    • DICOM is a document which defines a method of communication for various equipment of digital imaging devices/software now in use by the various medical imaging hardware manufacturers. It represents a progress in that it makes it possible to predict the interconnection of various image modalities, through a DOCUMENT OF CONFORMITY or conformance statement emailed from each machine/software following this standard. Thus, the standard makes it possible for the equipment to communicate remotely through a network or media(disk, tape). By ensuring the compatibility of the equipment and by eliminating proprietary formats.

    • From Dicom website:
    • DICOM is a global Information-Technology standard that is used in virtually all hospitals worldwide. Its current structure, which was developed in 1993, is designed to ensure the interoperability of systems used to: Produce, Store, Display, Process, Send, Retrieve, Query or Print medical images and derived structured documents as well as to manage related workflow.

    The universal format for PACS image storage and transfer is DICOM (Digital Imaging and Communications in Medicine)
  22. What is PACS?
    A picture archiving and communication system (PACS) is a medical imaging technology which provides economical storage of, and convenient access to, images from multiple modalities (source machine types).[1] Electronic images and reports are transmitted digitally via PACS; this eliminates the need to manually file, retrieve, or transport film jackets. The universal format for PACS image storage and transfer is DICOM (Digital Imaging and Communications in Medicine).Non-image data, such as scanned documents, may be incorporated using consumer industry standard formats like PDF (Portable Document Format), once encapsulated in DICOM.
  23. How is cervical cancer treated with RT?
    • 1)4-field box to 40-50 Gy
    • 2)Midline(or MLCs) block added to shield rectum, bladder
  24. Pelvic cancers that metastasize to inguinal nodes..(name 6)?
    • 1)cervix
    • 2)vulva
    • 3)distal 1/3 of vagina
    • 4)penis
    • 5)anal canal
  25. Pelvic fields are ___ MV 4-field box or AP/PA with an added  ____ ____ field to inguinal nodes.
    • 6/10-MV
    • AP electron
  26. The treatment of choice for prostate is..? For an open field technique, the field looks like a _____.
    • IMRT
    • stop sign
  27. The treatment of choice for bladder is ____because of its radiosensitivity.
    IMRT
  28. The most common malignancy in the testicles is _______. RT is given post-op(adjuvant radiotherapy), a scrotal shield is used for the remaining testicle, and the field looks like a _____or an inverted_____.
    The most common malignancy in the testicles is seminoma. RT is given post-op(adjuvant radiotherapy), a scrotal shield is used for the remaining testicle, and the field looks like a hockey stick or an inverted "Y".
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jaxkaty5437
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243970
Card Set
Treatment planning Chapter 13(pelvis)
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Treatment planning Chapter 13
Updated