In-111-leukocyte scintigraphy for detection of infection associated with peritoneal dialysis catheters

Imaging of Peritoneal Dialysis Complications in Children

Worldwide, peritoneal dialysis (PD) is the preferred renal replacement therapy option for children with end-stage renal disease who are awaiting transplantation. PD involves the instillation of a specifically formulated solution into the peritoneal cavity via a PD catheter, with two-way exchange of solutes and waste products along a concentration gradient. This exchange occurs across the peritoneal membrane. The PD catheter has intraperitoneal, abdominal wall, and external components. Enormous efforts have been directed to augment the efficiency and longevity of the peritoneum as a dialysis system by preventing PD-related infectious and noninfectious complications, which may otherwise result in technique failure and a subsequent temporary or permanent switch to hemodialysis. Imaging has an instrumental role in prompt diagnosis of PD complications and in guiding the management of these complications. The main imaging techniques used in the setting of PD complications-namely, conventional radiography, US, CT, MRI, and peritoneal scintigraphy-as well as the benefits and limitations of these modalities are reviewed. The authors also describe the frequently encountered radiologic findings of each complication. Familiarity with these features enables the radiologist to play a crucial role in early diagnosis of PD complications and aids the pediatric nephrologist in tailoring or discontinuing PD and transitioning to hemodialysis if necessary. Online supplemental material is available for this article. ^©RSNA, 2022.

[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.

Nuclear medicine studies in the dialysis patient

Nuclear medicine (scintigraphy) studies that are performed in patients being prepared for regular dialysis treatment include the measurement of renal clearance and dynamic studies of renal perfusion and function. Static scintigraphy with 99mTc-DMSA may be used in the evaluation of children at risk of renal damage and further functional deterioration. In patients on peritoneal dialysis, nuclear medicine procedures enable the diagnosis of structural complications such as intra-abdominal herniations and leaks. Diagnosis of infections of the vascular access sites in patients on hemodialysis and of the catheter tunnel in patients on peritoneal dialysis can be made with high diagnostic accuracy using radiolabeled, autologous leukocytes. Scintigraphy is valuable in delineating the extent of deposits of amyloid and parenchymal microcalcifications, and may be helpful in the functional evaluation of organs and tissues involved in the pathophysiology of renal impairment and dialysis. If radioiodine therapy with 131I is performed in patients on hemodialysis with benign or malignant thyroid disease, then pretherapeutic dosimetry is necessary to avoid over- and undertreatment. Radioiodine therapy in the dialysis patient leads to only insignificant contamination of dialysis equipment and marginal exposure to the medical staff.

111In-oxine labelled leukocyte scintigraphy in the detection and localization of active inflammation and sepsis

We report an analysis of the results obtained in our first 100 studies with indium-111-oxine labelled leukocyte scintigraphy, a diagnostic technique which has recently become available for clinical evaluation within Australia. We used this technique to assess patients with suspected sepsis or inflammation after other commonly used investigations had failed to confirm a diagnosis. Four patient subgroups were evaluated: fever of unknown origin; suspected abdominal or postoperative sepsis; suspected active inflammatory bowel disease; and suspected sepsis or inflammation of bones or joints. The course of all patients was followed for at least three months to establish the accuracy of the technique. The leukocyte labelling procedure took 90 min and imaging was carried out typically 3-6, 24 and occasionally 48 h after reinjection of the labelled autologous leukocytes. In one patient labelling of leukocytes was unsuccessful. In the remaining 99 studies the overall sensitivity of leukocyte scintigraphy was 88% (36 of 41 patients with a proved inflammatory or infective disease focus had positive scan findings); and the specificity was 95% (55 of 58 cases with no proved disease focus had normal scan findings). This series supports the use of this method as the imaging procedure of choice in nuclear medicine for the evaluation of suspected acute sepsis (symptoms less than four weeks' duration), of inflammatory bowel disease and of suspected infections involving appendicular bones which contain no active bone marrow. It is also a useful secondary scintigraphic procedure, after gallium-67-citrate scintigraphy, in patients with suspected infective disorders of more than four weeks' duration.