LWBK1006-20 LWW-Govindan-Review December 12, 2011 19:4
Chapter 20•Cancer of the Gastrointestinal Tract 249this type of CT, extension of the tumor to the superior mesenteric artery,
celiac axis, superior mesenteric vein/portal vein complex, and contiguous
structures can be clearly determined, as well as an assessment of distant
metastasis. Optimally, CT imaging should precede stent placement and
biopsy because of the possibility of postprocedure inflammation from the
biopsy and artifact from the stent that can confound interpretation of the
images. Magnetic resonance imaging has not been widely used to assess
pancreatic cancer. Endoscopic ultrasound can image the primary cancer
and be a means of obtaining a fine-needle aspiration of pancreatic adeno-
carcinoma, but in general the procedure is noncontributory when CT scan
characterizes the tumor. When a mass cannot be visualized on CT scan,
sonography through the wall of the stomach or duodenum can image
tumors in the body/tail and head of the pancreas, respectively. Although
preoperative ultrasonography is useful in assessing tumor characteristics
and resectability of pancreatic adenocarcinoma, it is particularly opera-
tor dependent. It has a high sensitivity and specificity (92.3% and 72.7%,
respectively) in defining superior mesenteric vein and portal vein invasion,
although lower than helical CT (98% and 79%, respectively).Answer 20.2.5. The answer is A.
Malabsorption is a frequent complication seen in patients after Whipple
surgery because of pancreatic enzyme insufficiency. Most patients require
adjustment of the pancreatic enzyme supplement for adequate control of
this symptomatology. Although small bowel obstruction and metastatic
disease can be seen, the patient’s clinical picture does not go along
with these diagnoses. The aim during adjuvant therapy is to adminis-
ter the chemotherapy with minimal delays to obtain the full benefit from
therapy.Answer 20.2.6. The answer is B.
The Radiation Therapy Oncology Group (RTOG) performed a prospec-
tive randomized trial (RTOG 9704) comparing gemcitabine with infu-
sional 5FU as the systemic component of therapy with all patients also
receiving 5FU-based chemoradiation. There was no survival difference
between patients randomized to gemcitabine and those who received
infusional 5FU. However, among the 380 patients with resected pancre-
atic head lesions, survival was superior for patients randomized to gemc-
itabine compared with those who received infusional 5FU (20.6 months
vs. 15.9 months; hazard ratio [HR] for death 0.79; 95% CI, 0.63 to
0.99;p=.033). In CONKO-001, patients randomized to receive gem-
citabine had a median disease-free survival of 13.9 months (95% CI,
11.4 to 15.3), whereas those patients who underwent surgery alone had
a median disease-free survival of only 6.9 months (95% CI, 6.1 to 7.8;
p=.001). However, there was no statistically significant difference in
overall survival. 5FU-based chemoradiation followed by up to 2 years of
weekly bolus 5FU was evaluated against observation alone in the GITSG
trial. A preliminary analysis of survival was reported after only 43 patients
had completed treatment and showed a striking survival advantage for