Accuracy of EUS in diagnosis of rectal cancer KKUH experience A.Aljebreen ,N. Azzam , S. Sharqawi,A.Alzubaidi,T.Alturiki

Colorectal cancer is the most common gastrontestinal malignancy and the second cause of cancer-related deaths in West countries

. Colorectal cancer represents an important health problem in western countries, with an increasing incidence in our area over the last few years.

The prognosis of rectal cancer is related to several factors, such as depth of tumoral invasion, number of metastatic lymph nodes, involvement of circumferential margin Preoperative staging is of great importance for adequate management.

Recent data have shown that preoperative radiation therapy can reduce tumor recurrence from 27% to 11% and improve the survival accurate local staging information is paramount for stratifying patients who would benefit from neoadjuvant therapy as well as for predicting the surgical approach . Improved survival with preoperative radiotherapy in resectable rectal cancer. Swedish Rectal Cancer Trial. NEngl JMed 1997;336:980^7.

EUS CT SCAN MRI with endorectal coil

EUS Several studies have shown a high accuracy rate of endoscopic ultrasound (EUS) in the preoperative staging of rectal cancer. These studies reported an overall accuracy of 83% (75−90%) for T stage and 75% (65−80%) for N stage. Bartram C. Gastroenterol Clin North Am 2002; 31: 827-39. Fusaroli P. Eur J Gastroenterol Hepatol 2005; 17: 293-301.

EUS Accuracy two large studies, each of which contained more than 400 patients; in these studies, accuracy was lower (i.e., 63.3% and 69%). most inaccuracy results from over staging of T2 lesions EUS cannot reliably distinguish an irregular outer rectal wall image as being due to peritumoral inflammation or transmural tumor extension. Marusch F, Koch A, Schmidt U, et al. Routine use of transrectal ultrasound in rectal carcinoma: results of a prospective multicenter study. Endoscopy 2002;34: 385^90

T-staging accuracy fell to 52% to 74% when a broader spectrum CT is other diagnostic modalities . Initial data showed CT T-staging accuracy of 79% to 94% in patients with primarily advanced T-stage disease T-staging accuracy fell to 52% to 74% when a broader spectrum of tumor sizes was analyzed The decrease accuracy for early-stage lesions confined to the rectal wall. These data suggest that CT T-stage accuracy improves in more locally advanced tumors. Nodal staging accuracy has ranged from 54% to 70% (11, 18). Rifkin MD. Radiology1989;170:319 Goldman S. Gastrointest Radiol 1991;16:259 ^ 63

MRI

MRI The use of MRI in staging rectal cancer was first reported in 1986 T-staging accuracy of 59% to 88% was reported The development of endorectal coils made detailed imaging of the rectal wall possible, with a corresponding improvement in T-staging accuracy of 71% to 91% Comparative studies of endorectal coil MRI and EUS have shown similar T-staging accuracyMaldjian C, Smith R, KilgerA, Schnall M, Ginsberg G, Kochman M. Endorectal surface coil MR imaging as a staging technique for rectal carcinoma: a comparison study to rectal endosonography. Abdom Imaging 2000;25:75^80.

EUS ,reliable ,safe ,no radiation or contrast CT SCAN ,MRI

Aim of the study The aim of the present study was to determine the accuracy of EUS for preoperative staging in patients with rectal cancer with or without preoperative chemoradiation.

METHODS From January 2004 to February 2008, 34 consecutive patients were referred for local staging of rectal cancer by EUS. These patients were stratified into two groups. Group I 15 paients underwent surgery after EUS evaluation with prior chemoradiation. Once we had the results of the histopathological staging (pTN), which was considered the gold standard, we compared the results of the previous EUS staging (TN) with those of the pTN . Group II 34 patients consisted we evaluated accuracy of CT Scan in staging rectal cancer we used EUS as the gold standard.

EUS accuracy in rectal cancer staging we prospectively included all patients with rectal cancer staged in our unit. We defined the following as inclusion criteria: tumors affecting the last 15 cm of the colon ; patients in whom we could perform a complete EUS staging examination and who were surgically treated . We took histological staging as gold-standard for the analysis of EUS staging results.

Patients were prepared only with two 250-cc enemas before the procedure,. No sedation was required in any patient, and all the explorations were performed by the same endoscopist with a radial echoendoscope (pentax)

Ct Scan of abdomen was reviewed with our radiologist who was not aware of EUS or Histopath result

Symptoms ABDOMINAL PAIN 40% ANAL PAIN 28% BLEEDING /RECTUM 94% DIARRHEA 31% CONSTIPATION ALTERD BOWEL HABBIT 22% ANOREXIA ANEMIA 18% WT LOSS 54%

Results 34 patients with rectal cancer during the mentioned period. Of these 12(36%)women and 22 (64%)men. Mean age was 54.7 ± (range: 21-87). Family HX of colon cancer 4 (11%) patients

The accuracy of Eus vs surgical pathologically defined T-stage (15 patients) 12 out of 15 patients were accurately staged (80%) 2/15 were overstaged (13%) and 1/15 were understaged (7%)

The accuracy of EUS vs surgical pathology in N staging 13/15 were accurately staged (87%) 2/15 were overstaged (13%) 0/15 were understaged (0%)

The accuracy of CT vs surgical pathologically defined T-stage (15 patients) 7/16 were accurately staged (44%) 6/16 were overstaged (38%) 3/16 were understaged (19%)  

The accuracy of CT vs surgical pathology in N staging 9/16 were accurately staged (56%) 5/16 were overstaged (31%) 2/16 were understaged (12.5%)

understaged Overstaged Accurately staged (7%) (13%) (80%) EUS T satge (0%) (87%) EUS N stage (19%) (38%) (44%) ECT Scan T stage (12.5%) (31%) (56%) CT Scan N stage

CT pelvis diagnostic accuracy of T staging when compared to EUS (34) 20/34 were accurately staged (58%) 6/34 were overstaged (17%) 8/34 were understaged (23%)

CT pelvis diagnostic accuracy of N staging when compared to EUS 20/34 were accurately N staged (58%) 10/34 were overstaged (29%) 4/34 were understaged (11%)

Accurately staged Overstaged understaged CT Scan T staging (58%) (17%) (23%) CT Scan N staging (29%) (11%)

In conclusion, we can affirm that, according to our data, EUS offers high accuracy for rectal cancer staging, with a good correlation with histological staging regarding T stage ,it is more safe ,noninvasive .

in our experience, the diagnostic accuracy of EUS for T and N staging of rectal cancer is 80% and 87% respectively, similar results as previously published for T staging for rectal cancer. But N staging was higher than published data

In our study the EUS was more accurate than the Ct scan in staging rectal cancer

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