Colonisation and infection of the paranasal sinuses in cystic fibrosis patients is accompanied by a reduced PMN response

AbstractBackgroundWe studied whether the sinuses might be foci for Pseudomonas aeruginosa lung infection.MethodsEndoscopic Sinus Surgery was performed in 78 CF patients; PFGE was used for bacterial genotyping. Material from sinuses and lungs were Gram-stained to detect biofilms. Immunoglobulins were measured in serum and saliva.ResultsWhen P. aeruginosa was cultured simultaneously from the sinuses and the lungs they were genetically identical in 38 of the 40 patients (95%). In the sinuses, P. aeruginosa formed biofilms with minimal cellular inflammation, probably because of a significantly higher local production of secretory IgA compared with IgG (p<0.001).ConclusionsWe have shown that P. aeruginosa form biofilm in the sinuses, which constitute an important bacterial reservoir for subsequent lung infection. The high amount of IgA in the upper airways probably protects P. aeruginosa from the inflammatory immune system, and they can proceed unnoticed into a permanent infectious focus that cannot be eradicated with antibiotics

68Ga-PSMA PET/CT compared with MRI/CT and diffusion-weighted MRI for primary lymph node staging prior to definitive radiotherapy in prostate cancer: a prospective diagnostic test accuracy study

BACKGROUND: The aim was to compare the diagnostic accuracy of 68Ga-PSMA PET/CT with conventional cross-sectional imaging and diffusion-weighted MRI (DW-MRI) for detecting lymph node metastasis (LNM) to stage prostate cancer patients. Twenty consecutive, newly- diagnosed prostate cancer patients were prospectively enrolled and underwent 68Ga-PSMA-11 PET/CT, anatomical MRI or contrast-enhanced CT, and DW-MRI prior to laparoscopic, template-based, extended lymph node dissection. Histopathological findings served as the reference test. RESULTS: Histopathology showed LNM in 13 of 20 patients (19 high-risk, 1 intermediate risk). Five patients had metastasis-suspected lymph nodes on 68Ga-PSMA PET/CT. Patient-based analysis showed that the sensitivity and specificity for detecting LNM were 39% and 100% with 68Ga-PSMA PET/CT, 8% and 100% with MRI/CT, and 36% and 83% with DW-MRI, respectively. The positive and negative predictive values were 100% and 49% with 68Ga-PSMA PET/C, 100% and 37% with MRI/CT, and 80% and 42% with DW-MRI. Of 573 dissected lymph nodes, 33 were LNM from 26 regions. True-positive LNM on 68Ga-PSMA PET/CT was 9-11 mm in diameter, whereas false-negative LNM had a median diameter of 4 mm, with only 3 of 30 lymph nodes being larger than 10 mm. LNM were positive for PSMA by immunostaining. CONCLUSIONS: The sensitivity of 68Ga-PSMA PET/CT was notably better than that of MRI/CT and comparable to that of DW-MRI. Some false positive findings with DW-MRI reduced its specificity and positive predictive value compared with those of 68Ga-PSMA PET/CT and MRI/CT

Prospective comparison of ⁶⁸Ga-PSMA PET/CT, ¹⁸F-sodium fluoride PET/CT and diffusion weighted-MRI at for the detection of bone metastases in biochemically recurrent prostate cancer

PurposeTo prospectively compare diagnostic accuracies for detection of bone metastases by Ga-68-PSMA PET/CT, F-18-NaF PET/CT and diffusion-weighted MRI (DW600-MRI) in prostate cancer (PCa) patients with biochemical recurrence (BCR).MethodsSixty-eight PCa patients with BCR participated in this prospective study. The patients underwent Ga-68-PSMA PET/CT, a F-18-NaF PET/CT and a DW600-MRI (performed in accordance with European Society of Urogenital Radiology guidelines, with b values of 0 and 600s/mm(2)). Bone lesions were categorized using a three-point scale (benign, malignant or equivocal for metastases) and a dichotomous scale (benign or metastatic) for each imaging modality by at least two experienced observers. A best valuable comparator was defined for each patient based on study-specific imaging, at least 12months of clinical follow-up and any imaging prior to the study and during follow-up. Diagnostic performance was assessed using a sensitivity analysis where equivocal lesions were handled as non-metastatic and then as metastatic.ResultsTen of the 68 patients were diagnosed with bone metastases. On a patient level, sensitivity, specificity and the area under the curve (AUC) by receiver operating characteristic analysis were, respectively, 0.80, 0.98-1.00 and 0.89-0.90 for Ga-68-PSMA PET/CT (n=68 patients); 0.90, 0.90-0.98 and 0.90-0.94 for (NaF)-Na-18 PET/CT (n=67 patients); and 0.25-0.38, 0.87-0.92 and 0.59-0.62 for DW600-MRI (n=60 patients). The diagnostic performance of DW600-MRI was significantly lower than that of Ga-68-PSMA PET/CT and (NaF)-Na-18 PET/CT for diagnosing bone metastases (p<0.01), and no significant difference in the AUC was seen between Ga-68-PSMA PET/CT and (NaF)-Na-18 PET/CT (p=0.65).Conclusion(68)Ga-PSMA PET/CT and F-18-NaF PET/CT showed comparable and high diagnostic accuracies for detecting bone metastases in PCa patients with BCR. Both methods performed significantly better than DW600-MRI, which was inadequate for diagnosing bone metastases when conducted in accordance with European Society of Urogenital Radiology guidelines