Imaging biomarkers of resistance to radiation therapy can inform and guide treatment management. Most studies have so far focused on assessing a single imaging biomarker. The goal of this study was to explore a number of different molecular imaging biomarkers (proliferation, hypoxia, metabolism) as surrogates of resistance to radiation therapy. In addition to tumor volume, pronounced tumor proliferative response quantified using FLT PET, especially when associated with high residual FLT PET at midtreatment, is a negative prognostic biomarker of outcome in canine tumors following radiation therapy. Neither FDG PET (metabolism) nor Cu-ATSM PET (hypoxia), which have been so far considered as top candidates, were predictive of outcome.
COBISS.SI-ID: 2862180
Purpose. To assess the short-term efficacy and safety of ultrasonographically (US)-guided high-intensity focused ultrasound (HIFU) ablation for treatment of benign solid thyroid nodules. Materials and Methods. This prospective study was approved by the institutional ethics committee, and written informed consent was acquired. HIFU ablation was performed in one session with US guidance and conscious sedation in 20 euthyroid patients (mean age, 44.5 years) with a benign solitary or dominant thyroid nodule. Thyroid nodule volume, US structure, and Doppler pattern were assessed at baseline, at 1 week, and at 1, 3, and 6 months after treatment. Adverse events associated with HIFU were evaluated. Statistical analysis was conducted by using repeated measures analysis of variance, the Student t test, χ2 test, and correlation analysis. Results. The mean ± standard deviation nodule volume was 4.96 mL ± 2.79 at the start of the study. Nodule volume had decreased to 3.05 mL ± 1.96 at the 3-month follow-up examination (n = 20, P ( .001), and reached 2.91 mL ± 2.43 by the 6-month follow-up examination (n = 16, P ( .001). By then, the mean volume reduction was 48.7% ± 24.3 (P ( .001). Isoechoic nodules showed greater reduction at 1 month than did hypoechoic nodules (31.6% ± 18.1 vs 16.4% ± 8.6, P = .053). Nodules with markedly increased blood flow showed smaller volume reduction at 3 months than did less-vascularized nodules (10.9% ± 14.5 vs 41.5% ± 20.3, P = .054). Minor transient complications (eg, subcutaneous edema, mild skin redness) were observed in two patients. Conclusion. Early data suggest that US-guided HIFU ablation is an effective and safe procedure for treatment of benign solid thyroid nodules. Initial US echogenicity and vascularization influence the ablation outcome.
COBISS.SI-ID: 2244524
Metabolic instability and high kidney retention of minigastrin (MG) analogues hampers their suitability for peptide receptor radionuclide therapy of CCK2/gastrin receptor expressing tumors. High kidney retention has been related to the N-terminal glutamic acids and could be substantially reduced byco-injection of polyglutamic acids or gelofusine. The aim of the present study was to investigate the influence of stereochemistry of N-terminal amino acid spacer on enzymatic stability and pharmacokinetics of 111In-DOTA-(D-Glu)6-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2 (111In-PP11-D) and 111In-DOTA-(L-Glu)6-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2 (111In-PP11-L). By use of circular dichroism measurements we demonstrate the important role of the secondary structure on the pharmacokinetics of the two MG analogues. The higher in vitro serum stability together with better tumor-to-kidney ratio of the (D-Glu)6-congener indicates that this MG analogue might be a good candidate for further clinical study.
COBISS.SI-ID: 3861873
A realistic model of a finger joint, healthy and affected by arthritis, was constructed. Reflectance and transmittance hyperspectral images were determined using 3D Monte Carlo light transport in the models. It was demonstrated, that two diagnostic windows exist in NIR and SWIR regions, and that transmittance image contains valuable information about the disease. The proposed diagnostic technique is being tested using an imaging device prototype in a clinical study.
COBISS.SI-ID: 28864551
In this work, the silicon photomultipliers (SiPMs) were tested for the first time as the photodetectors in Cherenkov TOF PET. The high photon detection efficiency of SiPMs led to a large improvement in detection efficiency. On the other hand, the time response of currently available SiPMs is not as good as that of previously used photodetectors. The SiPM dark counts introduce a new source of random coincidences in Cherenkov method, which would be overwhelming with present SiPM technology at room temperature. When the apparatus was cooled, its performance significantly improved
COBISS.SI-ID: 28934695