Endoscopic transrectal ultrasonography (EUS) is used to stage rectal cancer by assessing depth of invasion through rectal wall layers and/or involvement of lymph nodes. Preoperative EUS and pelvis CT findings were compared with post operative
pathologic
findings to evaluate the effectiveness of EUS in staging rectal cancer. We performed EUS in 38 patients (male 24, female 14, eman age 53 years) with rectal cancer diagnosed with colonoscopic biopsy. The Olympus GF-UM3 and EU-M3 endoscopic
ultrasound and
display system (7.5/12 MHz) was used. Examination was performed with saline enema and diazepam injection. Water filled ballon and free filling of rectum with deaerated water provide good image. Postoperative finding showed 1 cases of mucosal
cancer, 3
cases of submucosal involvement, 9 cases of proper muscle invasion and 25 cases of serosa and perirectal fat involvement. Overall accuracy of EUS in determination of depth of invasion was 84%(32/38). And in cases of relatively early stage of
rectal
cancer (mucosa and submucosa involvement), the accuracy was 75%(3/4). Moreover 1 case of prostate involvement could be correctly diagnosed with EUS. With preoperative pevis CT, it was impossible to diffrentiate layers of rectal wall. The
sensitivity of
perirectal fat invasion was 33%(8/2$) and the false positivity was 15%(2/13).
In conclusion, EUS appears to be promissing method for depth of invasion in pre-operative staging of rectal concer whereas CT scan is useful method for detection of distant metastasis. (Korean J Gastroenterol 1994 ; 26 : 491-497)
|