JOURNAL CLUB: Preparative Fasting for Contrast-Enhanced CT in a Cancer Center: A New Approach.

OBJECTIVE: Most diagnostic imaging centers ask patients to fast for 4-6 hours before contrast-enhanced CT. Previous studies have shown that prolonged fasting can be harmful. In addition, manufacturers of contrast agents claim that there is no special preparation needed before examination. The aim of this study was to evaluate the effects of preparative fasting on contrast-enhanced CT at a cancer center. SUBJECTS AND METHODS: Outpatients (n = 3206) were prospectively evaluated and randomly assigned to two groups: the 1619 patients in group 1 fasted for at least 4 hours before the examination, whereas the 1587 patients in group 2 received a light meal. Adverse symptoms observed before and after contrast agent administration were compared between groups. RESULTS: Adverse symptoms occurring after IV contrast agent administration were reported by 45 patients (1.5%) in group 1 and 30 patients (0.9%) in group 2. The most common symptoms were nausea (n = 32), weakness (n = 12), and vomiting (n = 5). The frequency of symptoms did not differ statistically significantly between groups (p > 0.05). CONCLUSION: In this sample of patients with cancer undergoing contrast-enhanced CT, very few adverse symptoms were reported regardless of preparative fasting. These results support the idea that preparation for contrast-enhanced CT can be simplified, decreasing the discomfort and inconvenience experienced by patients.

A New CT-Guided Modified Trocar Technique for Drainage of Difficult Locations Abscesses.

PURPOSE: Computed tomography (CT) is commonly used to guide drainage of deep-seated abdominal fluid collections. However, in some cases, these collections seem to be inaccessible due to surrounding organs or their being in difficult locations. The aim of this study is to describe a modified Trocar technique to drain collections in difficult locations, especially those in the subphrenic space, without passing through intervening organs. MATERIALS AND METHODS: This retrospective case series study describes seven inpatients who underwent CT-guided drainage using a modified Trocar technique for abscesses that are difficult to access percutaneously. All patients provided written informed consent prior to the procedure. After placement of a 12-14F catheter inside the peritoneum, the Trocar stylet was removed so that the tip of the catheter became blunt and flexible to avoid injury to organs and structures in the catheter route, and the catheter was slowly advanced towards the collection using CT guidance and tactile sensation. After reaching the target, the stylet was reintroduced to enter the abscess wall. RESULTS: All procedures were performed using an anterior abdominal wall access with adequate catheter positioning and resulted in clinical status improvement in the days after the drainage. No complications related to the procedure were identified in any of the patients. CONCLUSIONS: The modified Trocar technique for percutaneous CT-guided drainage of abdominal abscesses may be feasible for lesions that are difficult to access with conventional methods.

Computed tomography-guided percutaneous core needle biopsy in pancreatic tumor diagnosis.

AIM: To evaluate the techniques, results, and complications related to computed tomography (CT)-guided percutaneous core needle biopsies of solid pancreatic lesions. METHODS: CT-guided percutaneous biopsies of solid pancreatic lesions performed at a cancer reference center between January 2012 and September 2013 were retrospectively analyzed. Biopsy material was collected with a 16-20 G Tru-Core needle (10-15 cm; Angiotech, Vancouver, CA) using a coaxial system and automatic biopsy gun. When direct access to the lesion was not possible, indirect (transgastric or transhepatic) access or hydrodissection and/or pneumodissection maneuvers were used. Characteristics of the patients, lesions, procedures, and histologic results were recorded using a standardized form. RESULTS: A total of 103 procedures included in the study were performed on patients with a mean age of 64.8 year (range: 39-94 year). The mean size of the pancreatic lesions was 45.5 mm (range: 15-195 mm). Most (75/103, 72.8%) procedures were performed via direct access, though hydrodissection and/or pneumodissection were used in 22.2% (23/103) of cases and indirect transhepatic or transgastric access was used in 4.8% (5/103) of cases. Histologic analysis was performed on all biopsies, and diagnoses were conclusive in 98.1% (101/103) of cases, confirming 3.9% (4/103) of tumors were benign and 94.2% (97/103) were malignant; results were atypical in 1.9% (2/103) of cases, requiring a repeat biopsy to diagnose a neuroendocrine tumor, and surgical resection to confirm a primary adenocarcinoma. Only mild/moderate complications were observed in 9/103 patients (8.7%), and they were more commonly associated with biopsies of lesions located in the head/uncinate process (n = 8), than of those located in the body/tail (n = 1) of the pancreas, but this difference was not significant. CONCLUSION: CT-guided biopsy of a pancreatic lesion is a safe procedure with a high success rate, and is an excellent option for minimally invasive diagnosis.

Preoperative computed tomography-guided localization of ground-glass opacities with metallic clip.

Intraoperative localization of ground-glass opacities is difficult because they are not easy to palpate and may be invisible at radioscopy. Therefore, various techniques have been developed to improve intraoperative localization of these lesions, allowing an adequate surgical resection. The aim of this study is to report two cases of preoperative localization of ground-glass opacities through computed tomography-guided placement of a metallic clip inside the lesion and to discuss this new technique in comparison with those previously described.

Percutaneous biopsy based on PET/CT findings in cancer patients: technique, indications, and results.

OBJECTIVE: To describe a technique for CT-guided biopsy based on PET/CT findings and to evaluate the indications and results of the technique in cancer patients. METHODS: We evaluated all patients receiving CT-guided percutaneous biopsies whose indication was based on PET/CT findings at an oncology reference center from October 2009 to December 2010. The PET/CT images were evaluated side by side with noncontrast CT images to identify the lesion or area of interest to be biopsied. Biopsies were guided by CT with the needle directed at the area of metabolic activity identified in the PET/CT examination performed before the procedure. RESULTS: A total of 64 cases were included in this study. The most common lesion location was pulmonary (n = 28; 43.8%). The median of the lesions' greatest diameter and maximum SUV were 44.1 ± 31.6 mm (10-186 mm) and 8.4 ± 5.9 (2.1-34.0), respectively. The histologic results of the biopsies were negative for malignancy in 15 cases (23.4%), positive in 46 cases (71.9%), and inconclusive in 3 cases (4.7%). Lesions with an SUV ≥ 4.0 were more likely to be malignant (85.4% vs. 46.2%; P = 0.006). CONCLUSIONS: CT-guided biopsies should be used routinely for lesions identified or better characterized by PET/CT. The results of this study demonstrate that this method is reliable, secure, and very accurate diagnostically, revealing a high percentage of malignant lesions.