Metabolic pseudoprogression in a patient with metastatic KIT exon 11 GIST after 1 month of first-line imatinib: a case report.

Background: Positron emission tomography (PET) with 18-fluorodeoxyglucose (18FDG) has proven to be highly sensitive in the early assessment of tumor response in gastrointestinal stromal tumors (GIST), especially in cases where there is doubt or when the early prediction of the response could be clinically useful for patient management. As widely known, kinase mutations have an undoubtful predictive value for sensitivity to imatinib, and the inclusion of KIT and PDGFRa mutational analysis in the diagnostic workup of all GIST is now considered standard practice. Case presentation: Herein, we described in detail a case of an exon 11 KIT mutated-metastatic GIST patient, who presented an unexpected metabolic progression at the early 18FDG-PET evaluation after 1 month of first-line imatinib, unconfirmed at the liver biopsy performed near after, which has conversely shown a complete pathological response. Conclusions: This report aims to highlight the existence of this metabolic pseudoprogression in GIST at the beginning of imatinib therapy in order to avoid early treatment discontinuation. Therefore, an early metabolic progression during a molecular targeted therapy always deserves to be evaluated in the context of the disease molecular profiling, and in case of a discordant finding between functional imaging and molecular background, a short-term longitudinal control should be suggested.

Evaluation of incidence of acute transient dyspnea and related artifacts after administration of gadoxetate disodium: a prospective observational study.

AIMS: To evaluate motion artifacts, breath-hold failure, acute transient dyspnea, and clinical parameters during hepatic arterial phase of gadoxetate disodium-enhanced magnetic resonance (MR) imaging. METHODS: This was an institutional review board-approved observational prospective study (written informed consent acquired) performed in 250 consecutive patients, who underwent liver MR with a multiarterial phase technique. Oxygen saturation (SatO2) and heart rate (HR) were monitored, while patients reported subjective symptoms. Breath-holds were assessed using prospective acquisition correction technique (PACE) monitors. Three readers independently analyzed all images to establish the presence of motion artifacts. Nonparametric statistical testing and Fleiss' kappa were used. RESULTS: No statistical differences in SatO2 and HR values were observed during the entire length of MR examination. The PACE graphs showed an altered breath-hold in 16/250 patients (6.4%), however only 6 patients self-reported symptoms during the procedure, and among these 6 subjects, only 2 suffered from acute transient dyspnea (0.8%). Motion-related artifacts increased mostly in the third arterial phase of gadoxetate disodium acquisition (p < 0.0001): The artifacts incidence was 2.9% in the first phase; 4.0% in the second; and 19.5% in the third. This increase was mainly due to patients' inability to hold their breath for the entire duration of the examination. However, at least one gadoxetate disodium arterial phase without motion artifacts and adequate for acquisition timing, was acquired in all MR examinations. CONCLUSION: The incidence of breath-hold failure and acute transient dyspnea after gadoxetate disodium administration increased during the third arterial phase only. Our protocol allowed the acquisition of at least one arterial phase not compromised by motion artifacts and adequate for acquisition timing, in all patients.

Prostate Cancer Detection Rate with Koelis Fusion Biopsies versus Cognitive Biopsies: A Comparative Study.

OBJECTIVE: Targeted fusion biopsies have led to an improved prostate cancer (PCa) detection rate (CDR). Our aim was to assess if device-assisted fusion biopsies are superior to cognitive ones in terms of CDR. The association between multiparametric MRI parameters and PCa was also evaluated. METHODS: We retrospectively enrolled 50 patients who underwent transrectal biopsy with elastic fusion (Koelis; group KB, n = 25) or cognitive approach (group CB, n = 25). Targeted biopsies were done on targets, while a variable number of random biopsies were performed depending on the clinical case. RESULTS: The groups did not significantly differ in terms of age, prostate-specific antigen, prostate volume and previous biopsies. Mean number of random cores was significantly inferior in KB group (8.4 vs. 12.1) and mean number of targeted biopsies was significantly higher (3.6 vs. 2.6). CDR was higher in fusion biopsies (64 vs. 40%), with the gap becoming significant when considering CDR of MRI targets only (59 vs. 27%). The difference was marked for lesions ≤10 mm, where CDR was 52% in KB against 21% in CB group. CONCLUSIONS: According to our study, elastic fusion biopsies performed with Koelis achieve an increased per-patient and per-lesion CDR as compared to cognitive biopsies, especially in the case of lesions ≤10 mm.

Diffusion-weighted imaging and apparent diffusion coefficient values versus contrast-enhanced MR imaging in the identification and characterisation of acute pyelonephritis.

OBJECTIVE: To compare contrast-enhanced (CEMR) and diffusion-weighted (DWI) magnetic resonance imaging in diagnosing acute pyelonephritis (APN) and to assess ADC measurement reliability in differentiating among normal renal parenchyma, APN and abscesses. METHODS: Eighty-eight patients (80 women, mean age 36.5 years) with clinical suspicion of APN were retrospectively reviewed. An experienced observer quantified lesions with a score ranging from 0 to 3. DWI and CEMR were compared on the basis of the assigned score, total examination number (88) and on presence (36)/absence (52) of abscesses. ADC values, calculated at the healthy parenchyma, APN and abscessed were compared to each other. RESULTS: Agreement between CEMR and DWI was 94.3 % (83/88 patients; P < 0.05). In the APN group, DWI was awarded the highest visibility score compared to CEMR (P = 0.05), while in the abscess group CEMR had the highest score (P = 0.04). The difference between ADC values of the APN-healthy parenchyma and abscess-APN groups was significant (P < 0.05). The area under the ROC curve of ADC values of the APN-healthy and abscess-APN groups were found to be 0.94 (95 % CI; cutoff value = 2) and 0.78 (95 % CI; cutoff value = 1.2) respectively. CONCLUSIONS: Diffusion-weighted imaging appears reliable in the diagnosis and follow-up of acute pyelonephritis and could provide a reasonable alternative to contrast-enhanced magnetic resonance imaging.