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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., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the relationship between volumetric parameters calculated using semiautomatic quantification of lesions detected in 68Ga-labeled prostate-specific membrane antigen PET-computed tomography (68Ga-PSMA PET/CT) and clinical characteristics in prostate cancer (PCa) patients with biochemical recurrence., Methods: A total of 85 consecutive PCa patients with biochemical recurrence who underwent 68Ga-PSMA PET/CT at our institution from January 2019 to March 2020 were retrospectively assessed. 68Ga-PSMA PET/CT-derived volumetric parameters, including whole-body PSMA tumor volume (wbPSMA-TV) and whole-body total lesion PSMA (wbTL-PSMA), as well as the established maximum and mean standardized uptake value (SUVmax and SUVmean), were calculated for each patient. All PET-derived parameters were analyzed for correlation with prostate-specific antigen (PSA) levels and for association with Gleason scores., Results: Eighty-five patients with a mean age of 68.9 ± 7.8 years (range, 47-83 years) and a mean PSA level of 40.9 ± 92.1 ng/ml (range, 0.2-533.2 ng/ml) were analyzed. Volumetric parameters, that is, wbPSMA-TV and wbTL-PSMA, demonstrated a statistically significant correlation with PSA levels (r = 0.403 and r = 0.556, respectively, all at P < 0.001) and only the means of wbTL-PSMA were significantly different between the Gleason score groups (P < 0.05)., Conclusions: The results of our study indicate that 68Ga-PSMA PET/CT might be a valuable tool for the detection and follow-up of recurrence in PCa patients. 68Ga-PSMA PET/CT-derived quantitative volumetric parameters demonstrated a highly significant correlation with changes in PSA levels. Larger prospective studies are needed to help reveal the full potential of parameters such as PSMA-TV and TL-PSMA derived from PET imaging with 68Ga-PSMA., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the accuracy of technetium- 99m-methoxyisobutylisonitrile (Tc-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 Tc-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 Tc-MIBI SPECT/CT is more accurate than ultrasound for the preoperative identification of single PTAs in patients with pHPT who are candidates for MIP.