Assignment 2 Flashcards
List the four most common primary sites from which metastases can occur:
lung, prostate, breast, and kidney
TD 5/5: bladder
6500 cGy
TD 5/5: rectum
6000 cGy
TD 5/5: testes
100 cGy
TD 5/5: ovaries
200-300 cGy
TD 5/5: prostate
7000 cGy
TD 5/5: uterus
10000 cGy
TD 5/5: vagina
9000 cGy
TD 5/5: femoral head/neck
5200 cGy
TD 5/5: small bowel
4000 cGy
TD 5/5: colon
4500 cGy
How can the patient be positioned during CT Sim so that the small bowel is minimized in the treatment field?
the patient can be positioned prone on a bellyboard with a full bladder
when should the patient’s bladder be full or empty when treating the whole pelvis?
prostate: full
bladder: empty
ovarian: full
how can the bladder be localized on imaging?
Use Cystografin contrast via a Foley catheter
how can the rectum be localized on imaging?
Use a radiopaque rectal marker, or a rectal tube with barium
how can the vagina be localized on imaging?
Use a radiopaque vaginal marker, or a tampon dipped in barium
how can the prostate be localized on imaging?
use fiducials
What is the cisterna chyli and why is it important?
• It is a sac-like lymphatic organ anterior to L1/2 thought to be the origin of the thoracic duct, which is the main duct that collects lymph from the lower part of the body.
what is the vertebral level for the bifurcation of the abdominal aorta
L4
where does the spinal cord start?
foramen magnum
List the type of brachytherapy procedure used in the treatment of uterine cervix.
LDR or HDR using Tandem & Ovoid (aka. Colpostat) applicators (e.g. Fletcher Suite)
What are the most common applicators used?
Tandem & Ovoid (aka. Colpostat) applicators (e.g. Fletcher Suite)
What 2 radioactive materials are used in the treatment of the uterine cervix? What is the half life for each?
Cesium 137: 30 years (used in LDR)
Iridium 192: 74 days (used in HDR)
What type of brachytherapy procedure is used in the treatment of prostate cancer?
- Interstitial – permanent seed implants
* Iridium 192 – temporary needles
What 3 radioactive materials are used in prostate brachytherapy? List the half life of each.
- Iodine 125 (permanent) – 59.4 days
- Palladium 103 (permanent) – 17 days
- Iridium 192 (temporary) – 74 days
- Gold 198 (permanent) – 2.7 days
What is a Fletcher Applicator? How are they used?
• Tandem & Ovoids (aka. Colpostats). A tandem is inserted through the cervix into the uterus, and two ovoids are inserted into the lateral vaginal fornices. Both are stabilized with sterile gauze packing, which also serves to displace the rectum and bladder from the sources.
What is Point A and Point B?
• The anatomic points used historically for cervical and uterine treatment are points A and B. Point A, where the prescription dose is specified, is located 2 cm superior to the top of the ovoids along the tandem and 2 cm lateral to the tandem in the plane of the applicator. It is approximately where the uterine arteries and the ureters intersect, and is chosen to ensure that the part of the cervix located between point A and the applicator receives the prescription dose (at a minimum). Point B, located 2 cm superior to the top of the ovoids and 5 cm lateral to the patient midline, represents where the parametrial nodes are.
list the accompanying disease with the following tumor marker: CEA
colon, breast, SCLC, and rectum
list the accompanying disease with the following tumor marker: serum acid phosphatase
prostate
list the accompanying disease with the following tumor marker: AFP
testes, ovaries, and liver
the histological type of cervix cancer is
squamous cell carcinoma
what lymph nodes are at risk in cancer of the cervix?
Obturator, internal iliac, and external iliac
what is the most radiosensitive organ in the female reproductive system?
ovaries
what is the dose prescription for cervical cancer?
180 cGy/ fraction x 25 fx = 4500 cGy
in ovarian cancer, how does the disease spread?
seeding via cells suspended in abdominal fluid (ascites)
when treating ovarian cancer AP/PA, what critical organ (s) must be blocked in the field?
the kidneys
what is the histolgical type of endometrial cancer?
adenocarcinoma
