Koichi Nagata

PET/CT Colonography for the Preoperative Evaluation of the Colon Proximal to the Obstructive Colorectal Cancer

PurposeThis study was designed to evaluate the usefulness of 18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) colonography in preoperative diagnosis of the tumors proximal to obstructive colorectal cancers, which were defined as cancers that cannot be traversed colonoscopically.MethodsA whole-body PET/CT protocol for tumor staging and a protocol for CT colonography were integrated into one examination. No cathartic bowel preparation was used before this examination. Thirteen prospective patients with obstructive cancer were examined. We compared the detection rates for obstructive colorectal cancers and tumors proximal to the obstruction using air-inflated PET/CT colonography to intraoperative examinations, histopathologic outcome, and follow-up colonoscopy.ResultsPET/CT colonography correctly identified all 13 primary obstructive colorectal cancers and all 2 synchronous colon cancers proximal to the obstruction. The two synchronous colon cancers detected at PET/CT colonography were confirmed and removed at single-stage surgical procedures. PET/CT colonography was able to localize all colorectal cancers precisely. There were no false-negative or false-positive proximal colorectal cancers by PET/CT colonography. Other preoperative examinations missed the synchronous colon cancers.ConclusionsIn patients with obstructive colorectal cancers, preoperative PET/CT colonography provided valuable anatomic and functional information of the entire colon to properly address surgery of colorectal cancer.

Polyethylene glycol solution (PEG) plus contrast medium vs PEG alone preparation for CT colonography and conventional colonoscopy in preoperative colorectal cancer staging

PurposeThis study evaluated the usefulness of combined polyethylene glycol solution plus contrast medium bowel preparation (PEG-C preparation) followed by dual-contrast computed tomography enema (DCCTE) and conventional colonoscopy. The main purpose of these examinations is the preoperative staging of already known tumors.Materials and methodsOne hundred patients with colorectal tumors were alternately allocated to either a polyethylene glycol solution preparation (PEG preparation) group (n=50) or a PEG-C preparation group (n=50) before undergoing conventional colonoscopy and computed tomographic (CT) colonography. After conventional colonoscopy, multidetector row CT scans were performed. Air images were reconstructed for both groups; contrast medium images were additionally reconstructed for the PEG-C preparation group. DCCTE images were a composite of air images and contrast medium images without use of dedicated electronic cleansing software. Quality scores (the presence or absence of blind spots of the colon) were compared between the two groups.ResultsComplete tumor images were obtained by DCCTE for all 50 (100%) lesions in the PEG-C preparation group, as compared with only nine of the 50 lesions (18%) in the PEG preparation group (air-contrast CT enema). The overall quality score in the PEG-C preparation group was significantly better than that in the PEG preparation group (P<0.0001).ConclusionsDCCTE showed the entire colon without blind spots in nearly all patients in the PEG-C preparation group because the areas under residual fluid were reconstructed as contrast medium images. DCCTE and conventional colonoscopy after PEG-C preparation are feasible and safe procedures that can be used for preoperative evaluation in patients with colorectal cancer.

Intraoperative fluoroscopy vs. intraoperative laparoscopic ultrasonography for early colorectal cancer localization in laparoscopic surgery

BackgroundIn colorectal cancer (CRC) surgery, precise tumor localization is important for oncologically correct surgery and adequate tumor and lymph node resection margins. During laparoscopic surgery it is difficult to localize early CRC. The aim of this study was to compare the usefulness of two tumor localization techniques; intraoperative fluoroscopy and intraoperative laparoscopic ultrasonography.MethodsSeventeen patients with CRC necessitating preoperative marking were alternately allocated to either the fluoroscopy (F) group (n = 8) or the laparoscopic ultrasonography (LU) group (n = 9). A three-step technique was used. At first lesions were localized preoperatively by metallic clips that were colonoscopically applied proximally and distally to the tumor site. Second, computed tomography (CT) colonography was taken to obtain preoperative staging. The location of the metallic clips was confirmed by CT colonography, preoperatively. Third, in the F group, intraoperative fluoroscopy was performed to localize the applied clips. In the LU group, the applied clips were detected from the serosal aspect of the colon using intraoperative laparoscopic ultrasonography.ResultsIn all patients, colonoscopic metallic clips were successfully applied and preoperative CT colonography correctly detected the location of the tumor. Marking sites were detected precisely using intraoperative fluoroscopy or intraoperative laparoscopic ultrasonography in all cases, without complications. The mean detection time was 15.8 minutes in the F group and 7.0 minutes in the LU group (p = 0.005). In the LU group, two cases were technically difficult because of interruption of the ultrasound by intestinal air.ConclusionsBoth intraoperative fluoroscopy and intraoperative laparoscopic ultrasonography are safe and accurate techniques for intraoperative localization of early CRC. With regard to detection time, intraoperative laparoscopic ultrasonography is superior to intraoperative fluoroscopy. However, when there is a massive amount of intestinal air, intraoperative laparoscopic ultrasonography is cumbersome in localizing the lesion. Computed tomography colonography is useful for preoperative tumor localization and might be effective for shortening detection time during surgery.

Triple Colon Cancer Successfully Demonstrated by CT Air-Contrast Enema

Accessible online at: www.karger.com/dsu A 76-year-old man with abdominal discomfort was seen by a physician. Barium enema was performed and demonstrated a protruded lesion in half-circumference at the descending colon and a total obstruction at the distal transverse colon. No information of the proximal side of the obstruction was obtained (fig. 1). He was referred to our institution for further evaluation and treatment. Conventional colonoscopic examination failed to provide the information of the proximal side of the stenosis. Computed tomography air-contrast enema (CT enema) using multidetector-row CT was performed and it revealed another apple core sign in the proximal transverse colon. Diagnosis of synchronous triple colon cancers was made from CT enema (fig. 2). Extended right hemicolectomy was performed and all colon cancers were confirmed in the resected specimen (fig. 3). CT enema correctly showed all three lesions despite the tight stenosis of the transverse colon. The postoperative course was uneventful.

Double colorectal cancer only diagnosed by computed tomographic colonography.

A 58-year-old woman presented to her physician with rectal bleeding and intermittent diarrhea. Optical colonoscopy revealed a bulky tumor which was diagnosed as rectal cancer. She was referred to our institution for further evaluation and treatment. Slim optical colonoscopy showed an obstructive cancer in the rectosigmoid junction and no information of the proximal side of the obstruction. The patient then underwent computed tomographic (CT) colonography for further evaluation of the proximal side. Three-dimensional endoluminal ‘fly-through’ images revealed another protruded lesion in the proximal side of the obstruction. Diagnosis of synchronous double cancer was made by CT colonography. This CT data was not only used to create three-dimensional images but also to decide on a preoperative clinical staging. Laparoscopy-assisted high anterior resection was performed and T3 rectal cancer and T1 sigmoid colon cancer were confirmed in the resected specimen. Follow-up optical colonoscopy revealed no other tumors. CT colonography has recently become a popular preoperative examination tool with significant improvement in quality of image due to a rapid progress in computer technology. CT colonography correctly showed synchronous double cancer in our case and provided crucial information for planning surgery. We recommend that CT colonography should be used for evaluating the proximal side of obstructive colorectal cancer.

CT endoscopy for the follow-up of Cronkhite–Canada syndrome

Dear Editor: The Cronkhite–Canada syndrome is a rare nonhereditary disorder characterized by generalized gastrointestinal polyposis associated with ectodermal changes such as alopecia, hyperpigmentation, and onychodystrophy. Although Cronkhite–Canada syndrome is generally accepted to be a benign disorder, it was recently suggested that malignant changes in patients with this syndrome are not rare. Recent reports recommend periodic examinations of the gastrointestinal tract. In general, conventional endoscopy or conventional radiographic examinations (upper gastrointestinal series and barium enema) were chosen to monitor patients with Cronkhite–Canada syndrome. We report a patient with Cronkhite– Canada syndrome who responded to a regimen of prednisone, total parenteral nutrition, and multivitamin supplementation and who remains symptom-free for 4 years. In addition, we report our experience using multidetector-row computed tomography (CT) endoscopy in the follow-up of Cronkhite–Canada syndrome. The present case is the first case in literature that CT endoscopy is used for the follow-up of Cronkhite– Canada syndrome. A 68-year-old man was referred to a local hospital due to a 1-month history of severe water diarrhea and 1-year history of cutaneous hyperpigmentation. His body weight had fallen by 12 kg in the recent year. In addition, in the past 1 month, he noted a gradual loss of scalp hair. He was admitted to our university hospital for diagnosis and treatment. At admission, he had a chronically ill appearance, loss of scalp hair, pale conjunctiva, and bilateral lower leg edema. Ectodermal changes were also noted, including onychodystrophy of the fingernails and toenails and brownish pigmentation over the palms and soles. Neither focal abdominal tenderness nor mass could be found. The chest and heart were unremarkable. He had no family history of gastrointestinal polyposis. Laboratory data showed anemia (hemoglobin 8.8 g/dl), hypoproteinemia (total serum protein 3.5 g/dl), and hypoalbuminemia (serum albumin 1.5 g/dl). Other laboratory values including tumor markers showed no significant abnormalities. Moreover, proteinuria was not confirmed by urinalysis. Because of body weight loss combined with diarrhea, conventional colonoscopy was performed and revealed polyposis in the entire colon, rectum, and terminal ileum. These polyps were histologically defined as juvenile-type polyps with cystically dilated glands, stromal edema, and mild infiltration of inflammatory cells. On conventional esophagogastroduodenoscopy, numerous reddish K. Nagata (*) . Y. Sato . S. Endo . S.-e. Kudo Digestive Disease Center, Showa University Northern Yokohama Hospital, 35-1 Chigasaki-chuo, Tsuzuki-ku, Yokohama, 224-8503, Japan e-mail: Nagata7@aol.com Tel.: +81-45-9497000 Fax: +81-45-9497927