stomach Flashcards
when is a second CT sim done
when pt loses >10% body weight or when the patient has anatomy changes d/t weight loss
prep for ct SIM/ tx
both CT sim and tx pt should fast for 3 hours prior
CT sim pt will have both oral and IV contrast and will have a 4DCT scan to track tumour motion during tx
patient position for treatment
pt typically will have wing board +/- vac loc and triangle under knees, arms should b above head
CT scanning limits
t4-5 to ischial tuberosities
OARS in general
kidney, heart, liver, spinal cord, small bowel
kidney OAR
2/3 of one kidney should be spared
For proximal lesions >50% lt kidney is in the field therefore rt kidney should be spared
for distal lesions the lRT kidney is in the field and should be spared as much as possible
what is included in CTV of tumours of the proximal GE/gastric lesions
the tumour + LN + 3-5 cm of the distal esophagus
CTV of esophagus
tumour +1.5-2cm margin and LN
(perigastric, celiac, portahepatis, supra pancreatic, splenic hilar, pancreatic duodenal, local PA and retroperitoneal LN
avg field size
15x 15
tx borders
s: t7-8
I: l3-4
lat: edge of body
M: 2-4 cm from vertebral bodies
energy
10-18MV
DOSES
45-50.4/25-28
MOST common s &s
appetite loss, early satiety, abode discomfort, wt loss, anemia, n &v and tarry stools
duration of symptoms
<3 mos in 40% pst
>1 year in 20 % ptr
what s&s is most common in the anTRUM AND cardia
vomiting and dysphagia
+ common age
50-70 yo
M vs f
+ common in men
most common nationalities
most common in back hispanics and native americans than whites
most common pathology
adenocarcinoma
adenocarcinoma subtypes
diffuse and intestinal
which adenocarcinoma has the worst prognosis
diffuse
which adenocarcinoma subtype is most common
intestinal
where does intestinal and diffuse lesions most commonly occur
intestinal occur in distal areas and diffuse occur more commonly in the cardia
proximal vs distal tumours regarding nationality
proximal moe common in whites and distal tumours more common in astern countries
