PET and PET-CT imaging in infection and inflammation: Its critical role in assessing complications related to therapeutic interventions in patients with cancer.

Over the past decade, there has been an increasing evidence of false-positive FDG uptake in several infectious diseases and aseptic inflammatory processes. With the widespread application of FDG-PET imaging in oncology, the interpreting physicians have come across these conditions frequently leading to false-positive diagnosis. Such conditions can coexist with metastatic lesions in patients with cancer, and hence, early and accurate diagnosis or exclusion of infection and inflammation is of utmost importance for the optimal management of these patients. Also, this powerful imaging modality can play an invaluable role for the appropriate management of these complicated benign conditions. The present communication on this non-oncological application of FDG is intended as an educative primer for practicing oncologists on this very important aspect of PET-CT imaging with an ultimate aim for bettering patient management.

Clinical Evaluations of Prosthetic Vascular Graft Infection

Infection of a prosthetic vascular graft is a perilous complication, difficult to eradicate, and if not recognized or adequately treated eventually caused the prosthesis to malfunction, often with life- threatening hemorrhage. Authors retrospectively evaluated the 17 cases of prosthetic vascular graft infection to determine treatment modalities of graft infection from May 1983 to April 1997 at department of surgery, Yeungnam University Hospital. Aortic and peripheral vascular graft infection were 2 and 15 cases, and mortality rate were 50% and 13.3%, respectively. Amputation rate was 13.3% in peripheral vascular graft infection. Most of the patients had experienced symptoms and signs of infection, such as fever, leukocytosis, pus discharge, wound disruption and/or bleeding due to anastomotic disruption. The Most common pathogen was Staphylococcus aureus(12 cases) and others were Staphylococcus epidermidis(4 cases), Escherichia coli(1 cases). The most common site of infection was inguinal area(7 cases) that associated with repeated operation for thromboembolectomy. The diagnosis was made with Duplex ultrasonography, computed tomography and sinography. In one case of aorto-iliac bypass, graft-cutaneous fistula was found by sinography. Treament modalities were local antibiotic soaking dressing only (4 cases), rotational muscle flap(1 case), graft excision with revascularization(4 cases), and graft excision without revascularization(6 cases) in peripheral graft infection and aortic graft excision with extra-anatomic bypass graft(2 cases) in aortic graft infection with systemic antibiotic administration. In conclusion, prevention of vascular graft infection and early diagnosis of infection are very important. The time to infection after operation, infection sites, bacteological pathogens and general condition of patients are also important to select treatment modalities, such as local care only, muscle flap application, interposition graft, and removal of graft with or without revascularization.