Retroperitoneum Flashcards
Retroperitoneum
What are the superior and inferior borders of the retroperitoneum?
diaphragm
superior aspect of the pelvic diaphragm (levator ani coccygeus muscle)
Retroperitoneum
What are the anterior and posterior borders of the retroperitoneum?
anterior: posterior parietal peritoneum
posterior: transversalis fascia
Retroperitoneum
What are the posterior and lateral borders of the “anterior” pararenal compartment?
posterior: anterior renal fascia
lateral: lateroconal fascia
Retroperitoneum
What are the contents of the perirenal compartment?
kidneys and adrenals
Retroperitoneum
What compartment abuts the bare liver on the right and the subdiaphragmatic space on the left?
perirenal
Retroperitoneum
What is the anterior border of the posterior compartment?
anterior: posterior renal fascia
Retroperitoneum
What are the contents of the posterior compartment?
fat. no organs
Retroperitoneum
What compartments fuse to form the infrarenal retroperitoneal space?
anterior and posterior
Retroperitoneum
What are the two peak decades in the incidence of retroperitoneal tumor malignancies and their corresponding cause/tumor origin/histologies?
1st decade - neuroblastoma or germ cell tumors
6th decade - mesenchymal tumors
Retroperitoneum
What type of tumor is the most commonly diagnosed tumor of the retroperitoneum?
STS
Retroperitoneum
What is the primary treatment and is the only potentially curative option for localized disease?
Surgical resection
Retroperitoneum
Criteria for unresectable tumors
extensive major vessel involvement
spinal cord involvement
peritoneal implants
distant metastasis
Retroperitoneum
R1 resection is a high risk for local recurrence and is suggestive of an inferior survival as well.
TRUE or FALSE?
True (NCDB)
Retroperitoneum
The EORTC’s STRASS trial (62092) is currently investigating the use of preoperative RT vs. surgery alone.
What are the advantages of doing preoperative RT vs. postoperative RT?
Preop:
- gross tumor is clearly defined and smaller (no need to include entire operative bed)
- intact vascular supply, -> more sensitive to radiation (theoretically)
Retroperitoneum
After preoperative RT, surgery is delayed for 3-8 weeks and the patient is restaged or worked up.
If the patient’s disease progress, what is the goal of the next treatment?
Palliative
Retroperitoneum
After preoperative RT, surgery is delayed for 3-8 weeks and the patient is restaged or worked up.
If surgery was done and the patient had R1 resection, what is the next step?
-post-operative RT boost
(though this is discouraged by NCCN)
-consider pre-operative RT again in the setting of a local recurrence
(medj malabo to)
Retroperitoneum
After preoperative RT, surgery is delayed for 3-8 weeks and the patient is restaged or worked up.
If surgery was done and the patient had R2 resection, what is the next step?
re-resection
Retroperitoneum
Chemotherapeutic agents used in the downstaging of retroperitoneal tumors prior to definitive treatment?
AIM
doxorubicin/ifosfamide/mesna
Retroperitoneum
H&P+imaging follow-up schedule after definitive treatment?
every 3-6 months for the first 2-3 years,
every 6 months for the next 2 years,
then annually
Retroperitoneum
Pre-operative RT volumes
What is the expansion for the GTV to make the iGTV?
based on motion throughout the respiratory cyle.
Retroperitoneum
Pre-operative RT volumes
What is the expansion to make the ITV?
1.5 cm from the iGTV.
minus uninvolved bone, liver, kidney, (and skin)
extend 5 mm into any bowel and air cavities
Retroperitoneum
Pre-operative RT volumes
What is the expansion to make the ITV for tumors that extend to the inguinal canal?
inferior expansion should be 3 cm from the iGTV
Retroperitoneum
Pre-operative RT volumes
What is the expansion to make the CTV in a tumor where no 4-D CT was done?
from the GTV
2 to 2.5 cm superior-inferior
1.5 to 2 cm radially
(edited same way as ITV)
Retroperitoneum
Pre-operative RT volumes
What is the expansion to make the CTV in a tumor below the iliac creast?
1.5 cm uniformly
Retroperitoneum
Pre-operative RT
What is the standard RT dose?
50.4/1.8/28
or
50/2.0/25
Retroperitoneum
Pre-operative RT
What is the standard postoperative EBRT boost dose for microscopic residual?
16 to 18 Gy
Retroperitoneum
Pre-operative RT
What is the standard postoperative EBRT boost dose for gross macroscopic residual?
20 to 26 Gy
Retroperitoneum
RT
Dose constraints for the stomach?
V45Gy <100%
Retroperitoneum
RT
Dose constraints for the kidneys?
mean dose bilateral should be below 15 to 18 Gy
if only one kidney, V18Gy <15%
Retroperitoneum
RT
Dose constraints for the liver?
<26 Gy
Retroperitoneum
RT
Typical IORT doses prescribed using electrons for complete resection, microscopic residual, and gross residual, respectively.
10 Gy
12.5-15 Gy
15-20 Gy
Retroperitoneum
RT
What are the advantages of HDR-IORT over IOERT?
HDR-IORT allows for delivery of more conformal treatments along curved surfaces secondary to the flexible nature of the HAM applicator,
the ability to treat large fields without field matching,
and the ability to deliver radiation therapy to areas that may not necessarily be accessible with IOERT.
Retroperitoneum
RT
What are the advantages of IOERT over HDR-IORT?
HDR-IORT is limited to treating target
areas ≤0.5 cm thick.
IOERT can treat both superficial and deeper targets by
varying the electron energy employed for treatment.
Treatment with IOERT is
also generally shorter than HDR-IORT, thus decreasing the overall procedure
time.
Retroperitoneum
Main pattern of failure
Locoregional
Retroperitoneum
Gross total resection had significantly increase in survival compared to incomplete resection.
TRUE or FALSE?
True (103 vs. 18 months)
Retroperitoneum
Incomplete resection had significantly increase in survival compared to unresectable disease.
TRUE or FALSE?
False.
No significant difference
Retroperitoneum
Predictors of survival in the recurrent setting
longer time to recurrence
repeat resection
Retroperitoneum
Other lesions
What is the most common benign tumor in this location?
schwannomas
Retroperitoneum
Other lesions
What is the most common lymphoma in this location?
NHL
Retroperitoneum
Other lesions
What is the treatment for retroperitoneal schwanommas?
complete surgical resection whenever feasible.
adjuvant RT may be necessary
Retroperitoneum
(from in-service bank)
- The anatomy of the retroperitoneum is the following, EXCEPT
A. Anterior border is posterior parietal peritoneum
B. Posterior border is the transversalis fasica
C. Superior is the diaphragm
D. Inferior is the superior aspect of the levator ani
D
pelvic diaphragm which is levator ani and coccygeus
Retroperitoneum
(from in-service bank)
- Following preoperative radiation therapy in the definitive setting, surgical resection is typically delayed 5-10 weeks with radiographic restaging performed to assess for metastasis and treatment response.
A. True
B. False
B.
3-8
Retroperitoneum
(from in-service bank)
- The internal target volume is made using a 1.5-cm uniform margin expansion of the iGTV edited off of uninvolved bowels, bone, kidney, and liver.
A. True
B. False
B.
include a portion of bowel