Quantitative assessment of overall inflammatory bowel disease activity using labelled leucocytes: a direct comparison between indium-111 and technetium-99m HMPAO methods

Role of computed tomography enterography/magnetic resonance enterography: is it in prime time?

Today, cross-sectional imaging modalities, such as computed tomography enterography (CTE) and magnetic resonance enterography (MRE), are particularly suited to evaluate small bowel diseases, especially Crohn's disease (CD). It is well known that CTE/MRE can provide excellent assessment of disease activity as well as the macroscopic features, extramural abnormalities, and complications of the small intestine in patients with CD. In general, CTE is considered as the first-line modality for the evaluation of suspected inflammatory bowel disease and for long-term assessment or follow-up of these patients. Because of the advantage of lack of radiation, MRE is being used more frequently, especially in children or young patients with CD.

Role of MRI in Crohn's disease

The traditional imaging of Crohn's disease has relied on barium and computed tomography (CT) examinations. In recent years magnetic resonance imaging (MRI) has emerged as an imaging method that can be used in the diagnosis and assessment of Crohn's disease. The advantages of MRI include lack of ionizing radiation and its superior tissue contrast resolution. The clinical progression of Crohn's disease can be variable, and MRI can be used to assess inflammatory status, disease progression, and complications of Crohn's disease. MRI of the small bowel is an evolving technique and it has the potential to become the preferred technique for imaging of small bowel Crohn's disease in the future.

Cancer risk among the relatives of patients with pancreatic ductal adenocarcinoma

BACKGROUND/AIMS

Pancreatic cancer is a leading cause of cancer-related death; the most consistently identified risk factors are smoking and family history. Our aims were to examine familial aggregations of pancreas and other cancers, and to determine the relative risk of the family members.

METHODS

We prospectively collected data on the families of patients presenting with pancreatic ductal adenocarcinoma. Smoking habits and alcohol consumption of the probands were compared with the available statistics on the Italian population. Mortality from cancer was investigated in first-degree relatives, and age-dependent risks of dying from pancreatic cancer and other tumors were compared with background population levels.

RESULTS

Data for 570 families were collected, including 9,204 relatives. Probands were 3- to 5-fold more often heavy smokers than the general population, and 9.3% of them reported a positive family history of pancreatic cancer. In first-degree relatives, only mortality from pancreatic cancer was significantly increased (relative risk at age 85 years = 2.7). Lifetime risk of dying of pancreas cancer was 4.1% for the relatives of all probands, and was 7.2% for the relatives of probands who developed disease before 60 years of age.

CONCLUSIONS

The data suggest that genetic susceptibility to pancreatic cancer may be attributable, in addition to BRCA2, to moderate- to low-penetrance gene(s).

[Diagnosis of the infectious complications of continuous ambulatory peritoneal dialysis by 99mTc-HMPAO labelled leukocytes]

OBJECTIVE

To assess the utility of abdominal scintigraphy with 99mTc-HMPAO labelled leukocytes in the diagnosis of infectious complications of continuous ambulatory peritoneal dialysis (CAPD).

MATERIAL AND METHODS

17 patients in CAPD were evaluated (35 studies). They were divided into three groups: group control in asymptomathic patients (5), group of studies in patients with suspicion of exit site infection/catheter tunnel (18) and group of studies in patients with clinical suspicion of peritonitis (12). All patients underwent abdominal scintigraphy with 99mTc-HMPAO labelled leukocytes. The results were compared to final clinical diagnosis, assessing the exit site or dialysis liquid external aspect, material or exit site secretion culture and clinical follow up.

RESULTS

In the case studied, we obtained high sensitivity and specificity values for the exit site infection diagnosis (83 % and 75 % respectively), and a sensitivity of 100 % in the diagnosis of peritonitis as well. We detected a case of catheter tunnel infection confirmed by culture. No pathological uptake was observed in any control case.

CONCLUSIONS

Abdominal scintigraphy with 99mTc-HMPAO labelled leukocytes allows the early diagnosis of infectious complications of CAPD, and the control of treatment response, avoiding its unnecessary prolongation.

Quantification of disease activity in patients undergoing leucocyte scintigraphy for suspected inflammatory bowel disease

PURPOSE

Whole-body gamma camera counting is an alternative to faecal 111In collection for quantifying disease activity in inflammatory bowel disease (IBD) but requires administration of imaging activities of 111In. The aim of this study was to explore a dedicated whole-body counter which requires 20-fold less activity than gamma camera counting.

METHODS

Thirty patients with known or suspected IBD received 99mTc-granulocytes (approximately 200 MBq) and 111In-granulocytes (approximately 0.5 MBq). The 99mTc-cells were injected 45 min after the 111In-cells and immediately after a baseline 111In whole-body count. The decay-corrected count at 120 h was expressed as a fraction of baseline to give whole-body 111In retention (WBR). One patient was excluded as the injected cells were non-viable.

RESULTS

Median 45-min intravascular 111In recovery was 35% in patients compared with 43% in six normal volunteers (p<0.05). WBR in normals ranged from 91% to 93% and in 11 patients with negative 99mTc imaging from 87% to 96%. Only one of 11 patients with negative imaging had WBR <90% while 11/12 patients with WBR <90% had abnormal imaging. Ten of 13 patients with Crohn's disease (CD) had abnormal imaging. The lowest WBR in these ten was 77% and six had values of >90%. There was a significant association between WBR and 99mTc image grade (Rs=0.73, p<0.002) in 16 patients without CD, but not in 13 patients with CD (Rs=0.54, p>0.05).

CONCLUSION

Dedicated whole-body counting is able to quantify disease activity in IBD but may give normal values in active CD.

Technetium-99m HMPAO-labeled leukocyte imaging compared with endoscopy, ultrasonography, and contrast radiology in children with inflammatory bowel disease

BACKGROUND

The purpose of this study was to evaluate retrospectively the value of leukocyte-labeled scintigraphy, ultrasonography, and contrast radiography compared with endoscopy in children suspected of having inflammatory bowel disease (IBD).

METHODS

Twenty-eight children (17 boys; mean age, 10.2 years) with IBD based on standard colonoscopic, histologic, and radiologic criteria (16 with Crohn's disease, 5 with ulcerative colitis, 5 with nonspecific colitis, I with granulomatous disease, and I with Beh,cet's disease) were included. Endoscopic, ultrasonographic, and contrast radiologic examinations were realized for 28, 23, and 19 children respectively.

RESULTS

Sensitivity and specificity were 75% and 92% for leukocyte-labeled scintigraphy, 39% and 90% for ultrasonography, and 58% and 83% for contrast radiography. The authors noted discontinuous uptake for 14 of 15 true-positive results for patients with Crohn's disease and continuous uptake for 4 of 4 true-positive results for patients with ulcerative colitis. A negative correlation between scan activity index and Lloyd-Still clinical score was found for 11 patients with Crohn's disease (r = -0.77).

CONCLUSIONS

Leukocyte-labeled scintigraphy, a noninvasive and reproducible technique, is a useful tool in the diagnosis and therapeutic strategy of IBD, and provides information on the presence, the intensity, and the extent of the disease, particularly in the terminal ileum. Leukocyte-labeled scintigraphy may not replace colonoscopy with biopsies for diagnosis confirmation. Its reliability seems higher than that of ultrasonography.

Tc-99m HMPAO white blood cell scintigraphy in the assessment of the extent and severity of an acute exacerbation of ulcerative colitis

PURPOSE

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with frequent exacerbations, including the risk for toxic megacolon and severe complications. In very active disease, colonoscopy should not be performed to assess the severity and the extent of the disease. The aim of the current study was to determine whether Tc-99m HMPAO-labeled white blood cell (WBC) scintigraphy can be used as an alternative to colonoscopy to determine the extent and the severity of the disease in critically ill patients.

METHODS

Twenty consecutive patients (7 women, 13 men; age 38.1 +/- 13.1 years) who had a severe attack of UC underwent scintigraphy on the day of admission. Leukocytes were labeled with 200 MBq (5.35 mCi) Tc-99m HMPAO. Planar anterior and posterior imaging of the abdomen was performed 45 and 120 minutes after WBC reinjection. The tracer uptake in the different colon segments was scored visually compared with bone marrow uptake. A symptom score was made and C-reactive protein was measured as a serologic marker of inflammation. Rectosigmoidoscopy with biopsy was performed within 24 hours of scintigraphy. Scintigraphic, endoscopic, and histologic results were compared for disease activity.

RESULTS

The mean symptom score was 12.7 (+/-0.7) on a scale of 21, and mean the C-reactive protein level was 6.8 (+/-1.2) mg/l. No significant difference was found between the scintigraphic score of the rectum and the endoscopic or the histologic score. The best correlation was found with the latter (r = 0.66, P < 0.01). Based on the results of scintigraphy, disease involved the left side of the colon up to the splenic flexure in 10 patients. The other patients had pancolitis.

CONCLUSIONS

Disease severity can be determined adequately by planar WBC scintigraphy in patients with severe attacks of UC. Because the presence and severity of disease correlates well with endoscopic and histologic findings, WBC scintigraphy can assess disease extent without the need for colonoscopy. This decreases the number and severity of complications that can occur in already critically ill patients.

Clinical applications of technetium Tc 99m hexamethyl propylene amine oxime leukocyte scan in children with inflammatory bowel disease

BACKGROUND

Labeled leukocyte imaging is a helpful diagnostic tool in the detection of inflammation and sepsis. The technetium Tc 99m hexamethyl propylene amine oxime (99mTc HMPAO)-labeled leukocyte scan has been found to be more sensitive than the Indium-111 labeled leukocyte scan in detecting inflammatory bowel disease, with reported sensitivities of 95% to 100%. Experience with the 99mTc HMPAO-labeled leukocyte scan was examined and its clinical applications evaluated in the immediate treatment of patients with inflammatory bowel disease.

METHODS

A retrospective chart review was undertaken that included pediatric patients who underwent 99mTc HMPAO-labeled leukocyte scan at the James Whitcomb Riley Hospital for Children. The disease activity of patients with inflammatory bowel disease was assessed. The leukocyte scan was performed according to the manufacturer's specifications, and images were obtained 30 minutes and 2 hours after administration of the radiopharmaceutical.

RESULTS

During the period of July 1996 through November 1997, 41 scans were performed in 35 patients. Twenty-nine patients had histologically proven inflammatory bowel disease: 24 with Crohn's disease, 4 with ulcerative colitis, and 1 with indeterminate colitis. Active inflammatory bowel disease was suspected in 24 patients when the leukocyte scan was performed. Twenty of the 24 patients (83% sensitivity) had abnormal findings in leukocyte scans that prompted more aggressive management in 15 (75%). Six of the 15 who were receiving maximum medical therapy underwent surgical resection of severely affected bowel segments, and medical treatment was intensified in the other 9. The remaining 5 patients were receiving optimal medical therapy, instituted at their recent visit, and did not require further medication adjustments. Four of the 24 patients with active inflammatory bowel disease had normal leukocyte scans (17% false-negative rate), 3 of whom were receiving corticosteroid therapy at the time the scans were performed. All of the 11 patients in whom inflammatory bowel disease was in remission and 6 patients who did not have inflammatory bowel disease had normal findings in leukocyte scans (100% specificity).

CONCLUSIONS

Although a tissue diagnosis is still recommended, obtained during upper and lower gastrointestinal endoscopic examinations, and contrast radiography of the small bowel for the initial work-up of patients with suspected inflammatory bowel disease, the 99mTc HMPAO-labeled leukocyte scan is a safe and useful diagnostic adjunct for subsequent evaluation of patients known to have inflammatory bowel disease. The results of 99mTc HMPAO-labeled leukocyte scans directly influenced treatment of 75% of the study patients with active inflammatory bowel disease, which included the decision to refer patients for surgical intervention.