Chronic Diverticulitis vs. Colorectal Cancer: Role of the CTColonography after incomplete Optical Colonoscopy.

Transcription

1 Chronic Diverticulitis vs. Colorectal Cancer: Role of the CTColonography after incomplete Optical Colonoscopy. Poster No.: C-1426 Congress: ECR 2016 Type: Scientific Exhibit Authors: M. J. Martínez-Sapiña Llanas, S. A. Otero Muinelo, T. Pérez Ramos, C. Crespo García, P. Fernández Armendáriz, E Flores ; A Coruña/ES, La Coruña/ES, Coruña/ES Keywords: Cancer, Colonography CT, CT, Colon, Abdomen DOI: /ecr2016/C-1426 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 26

2 Aims and objectives Diverticular disease is an increasing pathology in occidental society because of its relation with age and unhealthy habits like poor-fiber diet. Diverticular disease affects 5-10% of people older than 45 and approximately to 80% of those older than 85 years old. About sex predilection, diverticular disease is more frequent in males, with a rate of 3:2. Diverticula represent small saccular herniations of the mucosa and submucosa through the muscular layers of the bowel wall, principally in the places where blood vessels penetrate the muscular layers. This relation between diverticula and penetrating blood vessels explains their tendency to bleed. Location of diverticula is variable, as they may appear wherever in the colon, but most of times they are located in sigma and descendent colon (in 75% of cases). There are not diverticula in the rectum. Colonic stenosis in chronic diverticular disease appears as a chronic complication of repeated inflammatory processes, leading to fibrosis and stenosis that might simulate cancer; that is why history of recurrent episodes of diverticulitis could help us making a diagnosis Fig. 1 on page 3. The main difficulty in the diagnosis of recurrent diverticulitis or chronic diverticular disease is to exclude the possibility of colon cancer because both are endemic in elderly population and they may coexist in the same patient. An increased risk for sigmoid location of tumors in patients with diverticula has been reported. A common explanation for the similar development of diverticulosis and colorectal neoplasia relates it to the slow colonic transit time for both conditions. Conventional Colonoscopy or Optical Colonoscopy (OC) is the standard technique for the diagnosis of colorectal cancer, but it is an invasive, even risky, and sometimes incomplete procedure (6-26%). Stenoses due to both entities mentioned before are often cause of incomplete conventional colonoscopy because of the inability to pass the endoscope through the stenosed sigma, and reiteration of the study with a gastroscope in a patient with an inflamed and friable colon is not exempt of risk: perforation, bleeding and complications derived from sedation resulting in contraindications for its performace. Since clinical implications and management are so different between diverticular disease and cancer, evaluation of colon when Optical Colonoscopy was incomplete or contraindicated represents an emerging indication for CT- Colonography (CTC). CT-Colonography is a relatively new, non-invasive and rapid imaging technique developed for colorectal cancer screening and so accepted by the American Cancer Society in CTC is currently implementing either as a screening technique or complementary to the OC when the first was, as told before, incomplete or Page 2 of 26

3 contraindicated. CTC allows a complete examination of the colon in two and threedimensional perspectives in a rapid, safe and well tolerated procedure with the advantage of showing extracolonic features. CTC provides a detailed map of the extension of the disease, the inner and outer contour of the bowel wall and an optimal assessment of its thickness. At CTC, differential diagnosis among those two diseases is often hampered by the overlapping of some CT features they share, making it challenging. If diverticular disease is confidently diagnosed, it will not be necessary to perform new OC o surgery, and will lead us to follow patients with CTC and/or with clinical state assessment. Thus, the aim of this study was to retrospectively identify morphologic findings at CTColonography that most reliably enable the differentiation of chronic diverticular disease from sigmoid carcinoma in patients with known diverticular disease and incomplete Optical Colonoscopy presenting with stenotic sigmoid lesions. Images for this section: Page 3 of 26

4 Fig. 1: Typical appearance of chronic diverticular disease that did not manifest as a mass or stenosis (not included in our study). Image in a 50-year-old man who underwent CTC because of rectal blood loss. Note the presence of a long affected segment and moderate wall thickening (arrow) with tapered ends (arrowhead) and presence of diverticula within the involved segment (asterisk). Preserved mucosa is demonstrated with contrast staining of folds. Page 4 of 26

5 Methods and materials Institutional review board approval was obtained for the study and the need for signed consent was waived for this retrospective study. Patients We retrospectively reviewed the CTC performed at Complejo Hospitalario Universitario de A Coruña from January, 2010 until September, 2013 finding 59 patients with known diverticular disease, incomplete OC and stenotic lesions in sigma suspicious of colorectal cancer. A Radiology Information System (RIS) and our Electronic Medical Records (IANUS) were used to identify CTCs, reports, further imaging examination, clinical information, histological diagnosis and follow-up. The median age of the patients was 73,93 years old (ranging 39 to 88). 23 of them were male and 36 female (Table 1 on page 7). Diagnosis of carcinoma or chronic diverticular disease was confirmed by surgery, visual diagnosis at endoscopy and biopsy or by negative clinical follow-up over at least two years after initial CTC if none of previous were available. CT-Scanning All patients underwent CTC according to our institution standard protocol. Before starting the test, the process was explained to the patients and they were asked for their cooperation. Informed consent was not required, because the risk from colonic perforation with automatic injectors is practically zero. Bowel preparation The bowel preparation was without cathartics agents with a fiber-free diet three days before the examination. The diet was completed with a liquid nutritional supplement (Isosource ) 1 day before scanning. Oral iodinated contrast (diatrizoate) was administrated two days before the examination in order to tag the stools: 3 doses of 7 cc diluted with water, 2 days before the CTC and 5 doses of 7 cc, diluted with water 1 day before the CTC, and a local action micro- enema (Micralax ) was administered the morning of exploration. Patients were asked to drink 2 liters of water a day. One hour prior the test, a relaxing intestinal agent (Buscopan ), was administered. It was contraindicated in cases of glaucoma, prostatic hypertrophy or heart disease. Page 5 of 26

6 Patients were asked to evacuate residual fluid and fecal material from the rectum just prior to CTC. A rubber catheter was inserted into the rectum and the colon was distended with an Automatic CO2 Injector System, with the patient in left lateral decubitus position and then slowly turned into supine. Between two and six liters of CO2 was mechanically insufflated and a Scout Topogram was obtained to evaluate the colonic distension. If the topograms showed incomplete colonic distension, additional CO2 was insufflated. Once complete distension, both supine and then prone CTC images were obtained by using a 32 or 64-detector row CT scanner (GE Medical Systems LightSpeed PRO 32 or GE Medical Systems LightSpeed VCT 64). In case of inadequate colonic segment distension in the two scan helix, a complementary lateral decubitus scan was performed. No intravenous contrast agent was administered. Scan Parameters Low radiation dose protocols with dose modulation and automatic milliamperage (maximum 140 mas) and 100 kv were used. Thickness: 1.25 mm. Standard reconstruction algorithm. Rotation time: 0.5 s. The acquired data were sent to the Workstation (Advantage Workstation 4.4, GE Medical System), equipped with a CTC Software for further study and manipulation. Software and Tools CTC Software with 2D and 3D visualization. Initial interpretation was using primary 3D navigation through colonic lumen with antegrade and retrograde way. The 2D study with axial reconstructions and MPR was used to complete the study and to resolve diagnostic problems. The post-processing tools available in order to facilitate and increase the diagnostic efficiency were: Virtual Dissection, Virtual Biopsy or Translucency, Second Read CAD and Electronic Subtraction of Fluid and Stool. Review of CTC images The reviewed morphologic signs were established after a literature searching for CT findings in chronic diverticular conditions and colon cancer. On the basis of this literature review, we hypothesized that the following morphologic signs could be promising discriminators (Table 2 on page 7): length of the stenotic segment, degree of bowel wall thickening, degree of distortion of mucosal folds, severity of the occlusion, morphology of the edges of the lesion, adjacent fascial thickening, fat infiltration and lymphadenopathy. Presence of diverticula within the stenosis was also considered. Page 6 of 26

7 Two trained and experienced in CTC radiologists (M.J.M.S. with more than 1500 CTC interpreted and C.G.C. with more than 500 CTC interpreted) retrospectively analyzed CTC data of 59 patients with incomplete OC and stenotic lesions in sigma, in order to exclude cancer in stenotic segments. In case of disagreement, the expertise of the most experienced reader was followed. All the measurements were taken in mm, using twodimensional transverse (axial), coronal and Multiple Plane Reconstruction (MPR) images from the best distended series (supine or prone), using standard soft tissue windowing. The readers, one by one patient, first selected the series in which the colon and particularly sigmoid colon was best distended and then stratified the degree of luminal narrowing, stenotic segment length, wall thickness, presence or not of pericolonic fat stranding, fascial thickening featuring or absent, lymphadenopathy, type of edges and mucosal fold preserved or destroyed pattern. Finally, they made a presumptive diagnosis of cancer or diverticular disease. Radiologists were blinded to the final results. Images for this section: Table 1: Patient Characteristics Page 7 of 26

8 Table 2: Criteria analized Page 8 of 26

9 Results In this study, 59 patients met the inclusion criteria for stenotic sigmoid abnormality, known diverticular disease and incomplete OC. Of those patients, 10 obtained a final diagnosis of sigmoid carcinoma, and 49 received the final diagnosis of chronic diverticular disease. Table 3 on page 11 shows the findings at CTC in patients with sigmoid carcinoma versus patients with chronic diverticular disease. In Figures 1 to 12, some of the morphologic criteria analyzed are shown. Carcinoma was seen in 5 men (5 out of 23; 21,74%) and in 5 women (out of 36; 13,89%). Nine diagnosis of carcinoma were confirmed at pathological evaluation of the surgical piece, and one was only assessed performing OC and biopsy, because of the refusal of the patient to undergo a surgical intervention. Diagnosis of the 49 cases of chronic diverticular diseases were confirmed with surgery and pathological examination of the specimen (n=6), OC with a gastroscope and biopsy (n=22), excluding malignancy with clinical following (during two years) and performing a CTC after 1 year (n=11), and only with 2-year clinical assessment (n=10). Both radiologists made a sure and consensual diagnosis in 9 of the 10 cases of cancer. All of those 9 cases had a bowel wall thickness greater than 15mm (more than 20 mm in 7 cases), completely destroyed mucosal fold pattern and shoulder phenomenon. Stenosis was short in 6 cases (#5 cm), moderate in 3 (>5-10 cm) and long in 1 case (>10 cm). All the 9 patients had severe occlusion occasioned by the stenosis. 1 of the patients with definitive diagnosis for cancer was not correctly radiologically classified: the lesion had tapered edges, the mural thickening was less than 15mm and presented a mild luminal occlusion ( Fig. 9 on page 19 ). 1 case of long stenotic segment (>10 cm), shouldering at the edges, distorted pattern in mucosal folds, lymphadenopathy, severe lumen occlusion and diverticula in stenotic segment was tagged as a cancer; but confirmed diagnosis revealed a chronic diverticular disease ( Fig. 6 on page 17 ). 1 patient with moderated long stenosis (9 cm), positive fascia sign, not infiltrated fat, completely distorted mucosa, without lymphadenopathy, diverticula within the stenosis and severe occlusion was tagged as cancer; but definitive diagnosis was diverticular disease ( Fig. 8 on page 18 ). 1 patient with a stenosis of 10 cm long, complete distortion of mucosal fold pattern, wall thickening greater than 20 mm, positive fascia sign, fat stranding, small lymphadenopathy Page 9 of 26

10 and severe luminal occlusion had a non-definitive edge features, so it could not be tagged as cancer means of CTC findings. Final diagnosis with biopsy was chronic diverticular disease ( Fig. 3 on page 14 ). 1 patient with long stenosis (>20 cm), severe wall thickening (16 mm), diverticula within the stenosis, peripheral fat infiltration, severe occlusion and tapered edges obtained from radiologists a doubtful diagnosis at CTC. Contrast enhanced CT was also performed and pathologic evaluation of surgical specimen diagnosed it as a diverticular disease with extense fibrosis and asbcesses ( Fig. 12 on page 22 ). 60% of patients with cancer showed short stenosis (#5 cm) and only the 10% had stenosis longer than 10 cm. Wall thickening was more pronounced in patients with carcinoma (median 18,7mm; range mm ), compared with those in patients with chronic diverticular disease (median, 11,2 mm; range 5-23 mm).wall thickening more than 15 mm was found in 9 of 10 cancers (90%) and in 13 of 49 cases of chronic diverticular disease (26,53%). Shoulder phenomenon was seen in 9 of 10 cancers (90%) and in 2 of 49 cases of chronic diverticular disease (4,08%). Severe occlusion was found in 9 cancers (90%) and in 17 of 49 chronic diverticular diseases (35,42%, one patient missing). All carcinomas showed complete distortion of the normal fold pattern (100%), but so did 10 of 49 cases corresponding to chronic diverticular disease (20,41%). 5 patients with carcinoma shown diverticula within the stenotic lesion (50%), so the isolated considering of this feature as a sign of benignity would lead us to fall into false negative results and consequently, into important misdiagnose. All the chronic diverticular disease cases featured with diverticula in the affected segment. Among a list of CTC findings useful in this differential diagnosis, the destroyed mucosa fold pattern, the wall thickening #15 mm and shouldering at the edges of the mass seem to be good predictors according to our results ( Table 4 on page 23 ). High values for Positive Predictive Value (PPV), Negative Predictive Value (NPV), Sensitivity and Specificity were obtained after the analysis of the edges of the lesions. Of all the cases showing shoulder phenomenon, we only found 2 false positive results and 1 false negative; meaning that both presence or absence of this feature good indicators for cancer or diverticular disease respectively. About mucosal distortion; we found a relatively low value for PPV (0,5) since we observed quite cases of distorted folds in benign diseases. Nevertheless, NPV keeps high, demonstrating that a preserved mucosal pattern is a trustable finding in benign Page 10 of 26

11 diseases, because 100% of cancer in our sample presented with completely destroyed mucosal fold pattern. Referring to mural thickening, we obtained a low PPV (0,4) due to the number of false positive results (13). We assumed that it could respond to the low prevalence of cancer in our series (0,17) and that all the patients included in the study had diverticular disease and stenosis some degree of mural thickening. NPV, sensitivity and specificity showed high values, supporting mural thickening # 15 mm as a good criterion for cancer. Finally, those three findings together demonstrated to be confident for a good differential diagnosis, even more when associated with other criteria also taken into account: short stenosis, severe occlusion, fat infiltration, absence of fascia thickening and presence of lymphadenopathy. Concerning the presence of diverticula within the stenosis as an indicator of inflammatory disease, it showed a low sensitivity (0,5) in our sample, since half of the patients with cancer featured with diverticula intra-lesion, so we did not consider this as such a good marker for benignity. Images for this section: Page 11 of 26

12 Table 3: CTC Findings Page 12 of 26

13 Fig. 1: Typical appearance of chronic diverticular disease that did not manifest as a mass or stenosis (not included in our study). Image in a 50-year-old man who underwent CTC because of rectal blood loss. Note the presence of a long affected segment and moderate wall thickening (arrow) with tapered ends (arrowhead) and presence of diverticula within the involved segment (asterisk). Preserved mucosa is demonstrated with contrast staining of folds. Page 13 of 26

14 Fig. 2: 70-year-old woman with unspecific abdominal pain and incomplete OC. CTC shows typical features on chronic diverticular disease: long affected segment with moderate wall thickening (arrow), diverticula, positive fascia sign (curved arrow), tapered edges and distorted but not destroyed mucosal folds. Page 14 of 26

15 Fig. 3: CTC belonging to a 39-year-old woman whose OC was incomplete due to an impassable stenosis 40 cm distant to the anus. CTC shows a moderate length stenosis in descendent colon, with no shouldering edges (arrowheads in sagital plane), diverticula (curved arrow), positive fascia sign (arrows) and mild bowel wall thickening (in axial slice). Chronic diverticular disease was confirmed after biopsy with gastroscope. Page 15 of 26

16 Fig. 4: Typical colon cancer. An 86-year-old man with rectal blood loss and incomplete OC. A typical axial image shows a short segment of sigmoid colon with severe wall thickening, shoulder phenomenon (arrow) and abscense of diverticula within the affected segment (arrowheads pointing diverticula out of the lesion). Virtual 3D images show the destroyed mucosal fold pattern. Page 16 of 26

17 Fig. 5: 86-year-old woman with abdominal pain and diarrhea, undergoing CTC because of incomplete OC. CTC shows a sigmoid cancer with severe occlusive, short stenosis with bulging edges (arrows) and great thickening of the bowel wall. We can see diverticula within the lesion (arrowhead), fatty infiltration and a completely distorted mucosa pattern (virtual 3D image). Fig. 6: The CTC performed to this 49-year-old woman showed a stenosis with severe lumen narrowing, mural thickening with shouldering at the edges (arrows), distortion of mucosal folds (3D reconstruction) and diverticula within the stenosis (curved arrow). Fat stranding close to the lesion is also present (arrowhead). Case of diverticular disease mimicking cancer. Page 17 of 26

18 Fig. 7: Sigmoid tumor. 61-year-old man with rectal blood loss and incomplete OC. A coronal reformatted image shows a short segment with severe wall thickening, shoulder phenomenon (arrow) and diverticula in the affected segment (arrowhead). Virtual 3D image shows a destroyed mucous pattern. Page 18 of 26

19 Fig. 8: This 79-year-old man underwent CTC because of abdominal pain and incomplete OC due to an impassable area. Moderate length stenosis with complete distortion of the mucosa, diverticula and positive fascia sign was documented (arrowhead). Adjacent fat was not affected but shouldering at the proximal end of the lesion (arrow) and severe occlusion of the lumen were evident. Definitive diagnosis was chronic diverticular disease appearing with cancer features. Page 19 of 26

20 Fig. 9: CTC in an 84-year-old woman with anemia shows sigmoid carcinoma with an atypical appearance, mimicking the appearance of chronic diverticular disease. No shoulder phenomenon was seen, edges of the lesion are tapered (arrow) and wall thickening is moderate. There is not peripheral fat infiltration either and diverticula are seen out of the stenotic segment (arrowhead). Page 20 of 26

21 Fig. 10: Atypical cancer showing tapered edges (arrow) in a 74-year-old man. Long stenosed segment of descendent colon with diverticula (arrowhead), severe mural thickening (star) and destroyed mucosal fold pattern (virtual 3D image). Page 21 of 26

22 Fig. 11: Two patients of 61 and 69 years old featuring with short stenoses, impassable for the endoscope. Tapered edges and moderate wall thickening are documented, corresponding to chronic evolution of diverticular disease. Page 22 of 26

23 Fig. 12: This contrast enhanced CT was performed after CTC in a patient with incomplete OC. Tapered edged stenosis (arrow), mural thickening containing a fluid collection (curved arrow) and fat infiltration meaning acute reactivation of chronic diverticular disease. Page 23 of 26

24 Table 4: PPV, NPV, Sensitivity and Specificity Page 24 of 26

25 Conclusion In our experience, CTC allowed to address the therapeutic management of patients with stenotic sigmoid lesions and diverticulosis, since we dismissed cancer in 79,66%. The strongest morphological signs to identify carcinoma were destroyed mucosal folds pattern, severe wall thickening and shoulder phenomenon. Some authors confirm that the most reliable sign to diagnose cancer is the absence of diverticula in the affected segment (oppositely to chronic diverticular disease), but their presence within the narrow area does not exclude the possibility of neoplasm, since we found 5 cancers out of a total of 10 (50%) showing diverticula within the affected stenotic segment. Personal information References 1.-Gryspeerdt S, Lefere P. Chronic diverticulitis vs. Colorectal Cancer: Findings on CTColonography. Abdominal Imaging 2912;37(6): Pickhart PJ, Hassan C, Halligan S.Marmo R. Colorectal Cancer: CT-Colonography and Colonoscpy for detection -Systematic Review and Meta-Analysis. Radiology 2011; 259(2): Kim DH, Pickhart PJ,Taylos AJ, et al. CT-Colonography versus Colonoscopy for the Detection on Advanced Neoplasia. N Engl. J. Med 2007; 357(14): Lips LM, Cremers PT,Pickhart PJ, Cremers SE,et al. Sigmoid Cancer versus Chronic Diverticular disease: Differentiating Features al CT Colonography. Radiology 2015; 275(1): Flor N, Rigamonti PPisani Ceretti A. Et al.diverticular Disease Severity Score based on CT Colonography. Eu Radiol 2013;23(10): Hern F, Jonas E, Holmstrom B, Josephson T et al. CT Colonography versus Colonoscopy in the Follow-up of Patients after Diverticulitis. A Prospective, Comparative Study. Clin. Radiol. 2007; 62(7): Page 25 of 26

26 7.-Sai VF, Velayos F, NeuhausJ, Westphalen AC. Colonoscopy after CT Diagnosis of Diverticulitis to Exclude Colon Cancer, a Systematic Literature Review. Radiology 2012;263 (2): Lefere P, Gryspeerdt S, Baekelandt M et al. Diverticular Disease in CT Colonography. Eur Radiol (6): L62-L74 9.-Pickhart PJ. Missed Lesions at CT Colonography: Lessons Learned. Abdom. Imag (1): Neri E, Turini F, Cerri F, Faggioni L et al. Comparison of CT Colonography versus Conventional Colonoscopy in Mapping the Segmental Location of Colon Cancer before Surgery. Neri E, Turini F, Cerri F, Faggioni L et al. Abdom Imag 2010;35(5): Atkin W,Dadswell E, Wooldrage K, et al. Computed Tomographyc Colonography versus Colonoscopy for Investigation of Patients with Symptoms Suggestive of Colorectal Cancer (SIGGAR): a Multicentre Randomised Trial. Lancet 2013;381(9873): Lee SJ, KimSA,Ku BH et al. Association Between Colorectal Cancer and Colonic Diverticulosis: Case-Control Study based on Computed Tomographyc Colonography. Abdom Imag 2012; 37( 1): Esgar, CT Colonography Working group. The second ESGAR consensus statement on CT Colonography. Eur Radiol 2013;23: Page 26 of 26