Purpose We sought to investigate the performance of radiomics analysis on baseline 18F-FDG PET/CT for predicting response to first-line chemotherapy in diffuse large B-cell lymphoma (DLBCL). Material and methods Forty-five patients who received first-line rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) chemotherapy for DLBCL were included in the study. Radiomics features and standard uptake value (SUV)-based measurements were extracted from baseline PET images for a total of 147 lesions. The selection of the most relevant features was made using the recursive feature elimination algorithm. A machine-learning model was trained using the logistic regression classifier with cross-validation to predict treatment response. The independent predictors of incomplete response were evaluated with multivariable regression analysis. Results A total of 14 textural features were selected by the recursive elimination algorithm, achieving a feature-to-lesion ratio of 1:10. The accuracy and area under the receiver operating characteristic curve of the model for predicting incomplete response were 0.87 and 0.81, respectively. Multivariable analysis revealed that SUVmax and gray level co-occurrence matrix dissimilarity were independent predictors of lesions with incomplete response to first-line R-CHOP chemotherapy. Conclusion Increased textural heterogeneity in baseline PET images was found to be associated with incomplete response in DLBCL.

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Background Stereotactic body radioablation therapy (SBRT) has recently been introduced with the ability to provide ablative energy noninvasively to arrhythmogenic substrate while reducing damage to normal cardiac tissue nearby and minimizing patients’ procedural risk. There is still debate regarding whether SBRT has a predominant effect in the early or late period after the procedure. We sought to assess the time course of SBRT’s efficacy as well as the value of using a blanking period following a SBRT session. Methods Eight patients (mean age 58 ± 14 years) underwent eight SBRT sessions for refractory ventricular tachycardia (VT). SBRT was given using a linear accelerator device with a total dose of 25 Gy to the targeted area. Results During a median follow-up of 8 months, all patients demonstrated VT recurrences; however, implantable cardioverter-defibrillator (ICD) and anti-tachycardia pacing therapies were significantly reduced with SBRT (8.46 to 0.83/per month, p = 0.047; 18.50 to 3.29/per month, p = 0.036, respectively). While analyzing the temporal SBRT outcomes, the 2 weeks to 3 months period demonstrated the most favorable outcomes. After 6 months, one patient was ICD therapy-free and the remaining patients demonstrated VT episodes. Conclusions Our findings showed that the SBRT was associated with a marked reduction in the burden of VT and ICD interventions especially during first 3 months. Although SBRT does not seem to succeed complete termination of VT in long-term period, our findings support the strategy that SBRT can be utilized for immediate antiarrhythmic palliation in critically ill patients with otherwise untreatable refractory VT and electrical storm.

Objective The aim of this study was to evaluate the accuracy of technetium- 99m-methoxyisobutylisonitrile (99mTc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) and ultrasound in preoperative localization of single parathyroid adenomas (PTAs) in patients with primary hyperparathyroidism (pHPT) who would be suitable for minimally invasive parathyroidectomy (MIP). Methods A retrospective study of 143 consecutive patients with biochemical evidence of hyperparathyroidism who underwent preoperative localization of parathyroid lesions using 99mTc-MIBI SPECT/CT and ultrasound, and proceeded to parathyroid surgery at our institution from January 2013 to January 2018. Of these, 125 had single adenomas and are the subject of this study. The sensitivity, positive predictive value (PPV) and accuracy of the two imaging techniques for the accurately identification and lateralization of PTAs were determined using histopathology as the criterion standard. Results Of 125 PTAs, the correct identification and lateralization were significantly higher by SPECT/CT than ultrasound. SPECT/CT and ultrasound detected lesions with histopathologically proven PTAs in 116 and 95 patients, respectively. The sensitivity, PPV and accuracy were 92.17, 94.64 and 87.60%, respectively, for SPECT/CT and 75.89, 90.43 and 70.25%, respectively, for ultrasound in lateralization analysis. Conclusions The results of our study indicate that 99mTc-MIBI SPECT/CT is more accurate than ultrasound for the preoperative identification of single PTAs in patients with pHPT who are candidates for MIP.

In patients with mechanical aortic and mitral valves and left ventricular (LV) tachycardia (VT), catheter ablation is technically challenging due to the limited access to the LV. Promising new alternatives to radiofrequency ablation include pulsed-field electroporation, percutaneous or surgical sympathetic neuromodulation, and noninvasive stereotactic radioablation therapy (SBRT). We herein describe the effect of SBRT as a bailout therapy on the management of a challenging VT case in the presence of double left-sided mechanical valves.